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Wright DFB, Hishe HZ, Stocker SL, Dalbeth N, Horne A, Drake J, Haslett J, Phipps-Green AJ, Merriman TR, Stamp LK. The development and evaluation of dose-prediction tools for allopurinol therapy (Easy-Allo tools). Br J Clin Pharmacol 2024; 90:1268-1279. [PMID: 38359899 DOI: 10.1111/bcp.16005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 02/17/2024] Open
Abstract
AIMS Dose escalation at the initiation of allopurinol therapy can be protracted and resource intensive. Tools to predict the allopurinol doses required to achieve target serum urate concentrations would facilitate the implementation of more efficient dose-escalation strategies. The aim of this research was to develop and externally evaluate allopurinol dosing tools, one for use when the pre-urate-lowering therapy serum urate is known (Easy-Allo1) and one for when it is not known (Easy-Allo2). METHODS A revised population pharmacokinetic-pharmacodynamic model was developed using data from 653 people with gout. Maintenance doses to achieve the serum urate target of <0.36 mmol L-1 in >80% of individuals were simulated and evaluated against external data. The predicted and observed allopurinol doses were compared using the mean prediction error (MPE) and root mean square error (RMSE). The proportion of Easy-Allo predicted doses within 100 mg of the observed was quantified. RESULTS Allopurinol doses were predicted by total body weight, baseline urate, ethnicity and creatinine clearance. Easy-Allo1 produced unbiased and suitably precise dose predictions (MPE 2 mg day-1 95% confidence interval [CI] -13-17, RMSE 91%, 90% within 100 mg of the observed dose). Easy-Allo2 was positively biased by about 70 mg day-1 and slightly less precise (MPE 70 mg day-1 95% CI 52-88, RMSE 131%, 71% within 100 mg of the observed dose). CONCLUSIONS The Easy-Allo tools provide a guide to the allopurinol maintenance dose requirement to achieve the serum urate target of <0.36 mmol L-1 and will aid in the development of novel dose-escalation strategies for allopurinol therapy.
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Affiliation(s)
- Daniel F B Wright
- School of Pharmacy, University of Otago, Dunedin, New Zealand
- Sydney Pharmacy School, University of Sydney, Sydney, Australia
| | - Hailemichael Z Hishe
- School of Pharmacy, University of Otago, Dunedin, New Zealand
- School of Pharmacy, Mekelle University, Mekelle, Tigray, Ethiopia
| | - Sophie L Stocker
- Sydney Pharmacy School, University of Sydney, Sydney, Australia
- Department of Clinical Pharmacology & Toxicology, St Vincent's Hospital Sydney, Darlinghurst, Australia
- Musculoskeletal Health, University of Sydney, Sydney, Australia
| | - Nicola Dalbeth
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Anne Horne
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Jill Drake
- Department of Rheumatology, Immunology and Allergy, Te Whatu Ora Health New Zealand Waitaha Canterbury, Christchurch, New Zealand
| | - Janine Haslett
- Department of Medicine, University of Otago, Christchurch, New Zealand
| | | | - Tony R Merriman
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
- School of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Lisa K Stamp
- Department of Rheumatology, Immunology and Allergy, Te Whatu Ora Health New Zealand Waitaha Canterbury, Christchurch, New Zealand
- Department of Medicine, University of Otago, Christchurch, New Zealand
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Stamp LK, Dalbeth N. Moving urate-lowering therapy in gout beyond guideline recommendations. Semin Arthritis Rheum 2024; 65:152358. [PMID: 38219395 DOI: 10.1016/j.semarthrit.2023.152358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/05/2023] [Accepted: 12/18/2023] [Indexed: 01/16/2024]
Abstract
The 'treat-to target serum urate strategy' when using urate-lowering therapy has been recommended by most specialist rheumatology societies for many years. An alternative "treat-to-avoid-symptoms" in gout has been suggested, albeit without a clear definition of what this means and how it might be implemented in clinical trials or clinical practice. This has hampered efforts to design clinical trials that compare the "treat-to-target [urate]" and "treat-to-avoid-symptoms" strategies in the long-term management of gout. In this review we consider the rationale for the treat-to-target urate strategy when using urate-lowering therapy, potential definitions of a "treat-to-avoid-symptoms" strategy, or perhaps what is not "treat-to-avoid-symptoms", and approaches that might address this uncertainty.
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Affiliation(s)
- Lisa K Stamp
- Department of Medicine, University of Otago, Christchurch, Christchurch, New Zealand.
| | - Nicola Dalbeth
- Faculty of Medicine, University of Auckland, Auckland, New Zealand
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3
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Wen YF, Brundage RC, Roman YM, Culhane-Pera KA, Straka RJ. Population pharmacokinetics, pharmacodynamics and pharmacogenetics modelling of oxypurinol in Hmong adults with gout and/or hyperuricemia. Br J Clin Pharmacol 2023; 89:2964-2976. [PMID: 37202871 PMCID: PMC10527451 DOI: 10.1111/bcp.15792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 05/04/2023] [Accepted: 05/10/2023] [Indexed: 05/20/2023] Open
Abstract
AIMS The aim of this study was to quantify identifiable sources of variability, including key pharmacogenetic variants in oxypurinol pharmacokinetics and their pharmacodynamic effect on serum urate (SU). METHODS Hmong participants (n = 34) received 100 mg allopurinol twice daily for 7 days followed by 150 mg allopurinol twice daily for 7 days. A sequential population pharmacokinetic pharmacodynamics (PKPD) analysis with non-linear mixed effects modelling was performed. Allopurinol maintenance dose to achieve target SU was simulated based on the final PKPD model. RESULTS A one-compartment model with first-order absorption and elimination best described the oxypurinol concentration-time data. Inhibition of SU by oxypurinol was described with a direct inhibitory Emax model using steady-state oxypurinol concentrations. Fat-free body mass, estimated creatinine clearance and SLC22A12 rs505802 genotype (0.32 per T allele, 95% CI 0.13, 0.55) were found to predict differences in oxypurinol clearance. Oxypurinol concentration required to inhibit 50% of xanthine dehydrogenase activity was affected by PDZK1 rs12129861 genotype (-0.27 per A allele, 95% CI -0.38, -0.13). Most individuals with both PDZK1 rs12129861 AA and SLC22A12 rs505802 CC genotypes achieve target SU (with at least 75% success rate) with allopurinol below the maximum dose, regardless of renal function and body mass. In contrast, individuals with both PDZK1 rs12129861 GG and SLC22A12 rs505802 TT genotypes would require more than the maximum dose, thus requiring selection of alternative medications. CONCLUSIONS The proposed allopurinol dosing guide uses individuals' fat-free mass, renal function and SLC22A12 rs505802 and PDZK1 rs12129861 genotypes to achieve target SU.
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Affiliation(s)
- Ya-Feng Wen
- Department of Experimental and Clinical Pharmacology,
College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA
| | - Richard C. Brundage
- Department of Experimental and Clinical Pharmacology,
College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA
| | - Youssef M. Roman
- Department of Pharmacotherapy & Outcomes Science,
School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, USA
| | | | - Robert J. Straka
- Department of Experimental and Clinical Pharmacology,
College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA
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Sekine M, Okamoto K, Pai EF, Nagata K, Ichida K, Hille R, Nishino T. Allopurinol and oxypurinol differ in their strength and mechanisms of inhibition of xanthine oxidoreductase. J Biol Chem 2023; 299:105189. [PMID: 37625592 PMCID: PMC10511816 DOI: 10.1016/j.jbc.2023.105189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 08/27/2023] Open
Abstract
Xanthine oxidoreductase is a metalloenzyme that catalyzes the final steps in purine metabolism by converting hypoxanthine to xanthine and then uric acid. Allopurinol, an analog of hypoxanthine, is widely used as an antigout drug, as xanthine oxidoreductase-mediated metabolism of allopurinol to oxypurinol leads to oxypurinol rotation in the enzyme active site and reduction of the molybdenum Mo(VI) active center to Mo(IV), inhibiting subsequent urate production. However, when oxypurinol is administered directly to a mouse model of hyperuricemia, it yields a weaker urate-lowering effect than allopurinol. To better understand its mechanism of inhibition and inform patient dosing strategies, we performed kinetic and structural analyses of the inhibitory activity of oxypurinol. Our results demonstrated that oxypurinol was less effective than allopurinol both in vivo and in vitro. We show that upon reoxidation to Mo(VI), oxypurinol binding is greatly weakened, and reduction by xanthine, hypoxanthine, or allopurinol is required for reformation of the inhibitor-enzyme complex. In addition, we show oxypurinol only weakly inhibits the conversion of hypoxanthine to xanthine and is therefore unlikely to affect the feedback inhibition of de novo purine synthesis. Furthermore, we observed weak allosteric inhibition of purine nucleoside phosphorylase by oxypurinol which has potentially adverse effects for patients. Considering these results, we propose the single-dose method currently used to treat hyperuricemia can result in unnecessarily high levels of allopurinol. While the short half-life of allopurinol in blood suggests that oxypurinol is responsible for enzyme inhibition, we anticipate multiple, smaller doses of allopurinol would reduce the total allopurinol patient load.
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Affiliation(s)
- Mai Sekine
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan; Department of Pathophysiology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan.
| | - Ken Okamoto
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Emil F Pai
- Departments of Biochemistry and Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Princess Margaret Cancer Centre, Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Koji Nagata
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Kimiyoshi Ichida
- Department of Pathophysiology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Russ Hille
- Department of Biochemistry, University of California, Riverside, California, USA
| | - Takeshi Nishino
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
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Hishe HZ, Stocker SL, Stamp LK, Dalbeth N, Merriman TR, Phipps-Green A, Wright DFB. The impact of genetic variability in urate transporters on oxypurinol pharmacokinetics. Clin Transl Sci 2023; 16:422-428. [PMID: 36398357 PMCID: PMC10014700 DOI: 10.1111/cts.13460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 11/02/2022] [Accepted: 11/08/2022] [Indexed: 11/19/2022] Open
Abstract
The genetic determinants of the allopurinol dose-concentration relationship have not been extensively studied. We aimed to clarify what factors, including genetic variation in urate transporters, influence oxypurinol pharmacokinetics (PKs). A population PK model for oxypurinol was developed with NONMEM (version 7.3). The influence of urate transporter genetic variants for ABCG2 (rs2231142 and rs10011796), SLC2A9/GLUT9 (rs11942223), SLC17A1/NPT1 (rs1183201), SLC22A12/URAT1 (rs3825018), SLC22A11/OAT4 (rs17300741), and ABCC4/MRP4 (rs4148500), as well as other participant factors on oxypurinol PKs was assessed. Data from 325 people with gout were available. The presence of the T allele for ABCG2 (rs2231142) and SLC17A1/NPT1 (rs1183201) was associated with a 24% and 22% increase in oxypurinol clearance, respectively, in univariate analysis. This effect was not significant in the multivariate analysis. In the final model, oxypurinol PKs were predicted by creatinine clearance, diuretic use, ethnicity, and body weight. We have found that genetic variability in the transporters examined does not appear to influence oxypurinol PKs.
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Affiliation(s)
- Hailemichael Z Hishe
- School of Pharmacy, University of Otago, Dunedin, New Zealand.,School of Pharmacy, Mekelle University, Mekelle, Tigray, Ethiopia
| | - Sophie L Stocker
- School of Pharmacy, University of Sydney, New South Wales, Sydney, Australia.,Department of Clinical Pharmacology & Toxicology, St. Vincent's Hospital Sydney, Darlinghurst, New South Wales, Australia
| | - Lisa K Stamp
- Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Nicola Dalbeth
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Tony R Merriman
- Department of Biochemistry, University of Otago, Dunedin, New Zealand.,Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Tayama Y, Sugihara K, Sanoh S, Miyake K, Kitamura S, Ohta S. Xanthine oxidase and aldehyde oxidase contribute to allopurinol metabolism in rats. J Pharm Health Care Sci 2022; 8:31. [PMID: 36476607 PMCID: PMC9730672 DOI: 10.1186/s40780-022-00262-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 10/20/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Allopurinol is used to treat hyperuricemia and gout. It is metabolized to oxypurinol by xanthine oxidase (XO), and aldehyde oxidase (AO). Allopurinol and oxypurinol are potent XO inhibitors that reduce the plasma uric acid levels. Although oxypurinol levels show large inter-individual variations, high concentrations of oxypurinol can cause various adverse effects. Therefore, it is important to understand allopurinol metabolism by XO and AO. In this study we aimed to estimate the role of AO and XO in allopurinol metabolism by pre-administering Crl:CD and Jcl:SD rats, which have known strain differences in AO activity, with XO inhibitor febuxostat. METHODS Allopurinol (30 or 100 mg/kg) was administered to Crl:CD and Jcl:SD rats with low and high AO activity, respectively, after pretreatment with or without febuxostat. The serum concentrations of allopurinol and oxypurinol were measured, and the area under the concentration-time curve (AUC) was calculated from the 48 h serum concentration-time profile. In vivo metabolic activity was measured as the ratio AUCoxypurinol /AUCallopurinol. RESULTS Although no strain-specific differences were observed in the AUCoxypurinol/AUCallopurinol ratio in the allopurinol (30 mg/kg)-treated group, the ratio in Jcl:SD rats was higher than that in Crl:CD rats after febuxostat pretreatment. Contrastingly, the AUC ratio of allopurinol (100 mg/kg) was approximately 2-fold higher in Jcl:SD rats than that in Crl:CD rats. These findings showed that Jcl:SD rats had higher intrinsic AO activity than Crl:CD rats did. However, febuxostat pretreatment substantially decreased the activity, as measured by the AUC ratio using allopurinol (100 mg/kg), to 46 and 63% in Crl:CD rats and Jcl:SD rats, respectively, compared to the control group without febuxostat pretreatment. CONCLUSIONS We elucidated the role of XO and AO in allopurinol metabolism in Crl:CD and Jcl:SD rats. Notably, AO can exert a proportionately greater impact on allopurinol metabolism at high allopurinol concentrations. AO's impact on allopurinol metabolism is meaningful enough that individual differences in AO may explain allopurinol toxicity events. Considering the inter-individual differences in AO activity, these findings can aid to dose adjustment of allopurinol to avoid potential adverse effects.
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Affiliation(s)
- Yoshitaka Tayama
- grid.412153.00000 0004 1762 0863Faculty of Pharmaceutical Science, Hiroshima International University, 5-1-1 Hirokoshingai, Kure-shi, Hiroshima, 737-0112 Japan
| | - Kazumi Sugihara
- grid.412153.00000 0004 1762 0863Faculty of Pharmaceutical Science, Hiroshima International University, 5-1-1 Hirokoshingai, Kure-shi, Hiroshima, 737-0112 Japan
| | - Seigo Sanoh
- grid.412857.d0000 0004 1763 1087School of Pharmaceutical Health Sciences, Wakayama Medical University, 25-1 Shichibancho, Wakayama, 640-8156 Japan
| | - Katsushi Miyake
- grid.412153.00000 0004 1762 0863Faculty of Pharmaceutical Science, Hiroshima International University, 5-1-1 Hirokoshingai, Kure-shi, Hiroshima, 737-0112 Japan
| | - Shigeyuki Kitamura
- grid.444657.00000 0004 0606 9754Nihon Pharmaceutical University, Komuro 10281, Inamachi, Kitaadachi-gun, Saitama, 362-0806 Japan
| | - Shigeru Ohta
- grid.412857.d0000 0004 1763 1087School of Pharmaceutical Health Sciences, Wakayama Medical University, 25-1 Shichibancho, Wakayama, 640-8156 Japan
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Bathini L, Garg AX, Sontrop JM, Weir MA, Blake PG, Dixon SN, McArthur E, Muanda FT. Initiation Dose of Allopurinol and the Risk of Severe Cutaneous Reactions in Older Adults With CKD: A Population-Based Cohort Study. Am J Kidney Dis 2022; 80:730-739. [PMID: 35644439 DOI: 10.1053/j.ajkd.2022.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 04/08/2022] [Indexed: 02/02/2023]
Abstract
RATIONALE & OBJECTIVE Allopurinol should be started at lower doses in patients with chronic kidney disease (CKD) to avoid adverse effects. We examined the risk of severe cutaneous reactions in older adults with CKD who were newly prescribed allopurinol at varied doses. STUDY DESIGN Population-based cohort study using linked health care databases. SETTING & PARTICIPANTS Patients in Ontario, Canada (2008-2019) aged ≥66 years, with an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m2, and who were new users of allopurinol. EXPOSURE A new prescription for allopurinol >100 mg/d versus a dose ≤100 mg/d. OUTCOME The primary outcome was a hospital visit with a severe cutaneous reaction within 180 days of starting allopurinol. Secondary outcomes included all-cause hospitalization and all-cause mortality. ANALYTICAL APPROACH The exposure and referent groups were balanced on indicators of baseline health using inverse probability of treatment weighting on the propensity score. Weighted risk ratios (RR) were obtained using modified Poisson regression and weighted risk differences (RD) using binomial regression. RESULTS Of 47,315 patients (median age, 76 years; median eGFR, 45 mL/min/1.73 m2), 55% started allopurinol at >100 mg/d. Starting allopurinol at >100 versus ≤100 mg/d was associated with an increased risk of a severe cutaneous reaction: number of events (weighted), 103 of 25,802 (0.40%) versus 46 of 25,816 (0.18%), respectively (weighted RR, 2.25 [95% CI, 1.50-3.37]; weighted RD, 0.22% [95% CI, 0.12%-0.32%]. Starting allopurinol at >100 versus ≤100 mg/d was associated with an increased risk of all-cause hospitalization but not with all-cause mortality. LIMITATIONS This study was underpowered to detect risk differences in the association of allopurinol dose with outcomes across eGFR categories (ie, 45-59, 30-44, and <30 mL/min/1.73 m2). CONCLUSIONS Older patients with CKD who started allopurinol at >100 mg/d versus ≤100 mg/d were twice as likely to visit a hospital with a severe cutaneous reaction in the next 180 days.
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Affiliation(s)
- Lavanya Bathini
- ICES, Ontario, Canada; Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada.
| | - Amit X Garg
- ICES, Ontario, Canada; Department of Epidemiology & Biostatistics, Western University, London, Ontario, Canada; Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada
| | - Jessica M Sontrop
- ICES, Ontario, Canada; Department of Epidemiology & Biostatistics, Western University, London, Ontario, Canada
| | - Matthew A Weir
- ICES, Ontario, Canada; Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada
| | - Peter G Blake
- Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada
| | - Stephanie N Dixon
- ICES, Ontario, Canada; Department of Epidemiology & Biostatistics, Western University, London, Ontario, Canada
| | - Eric McArthur
- ICES, Ontario, Canada; Department of Epidemiology & Biostatistics, Western University, London, Ontario, Canada
| | - Flory T Muanda
- ICES, Ontario, Canada; Department of Epidemiology & Biostatistics, Western University, London, Ontario, Canada
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Bletsa E, Paschou SA, Tsigkou V, Stampouloglou PK, Vasileiou V, Kassi GN, Oikonomou E, Siasos G. The effect of allopurinol on cardiovascular outcomes in patients with type 2 diabetes: a systematic review. Hormones (Athens) 2022; 21:599-610. [PMID: 36197637 DOI: 10.1007/s42000-022-00403-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 09/27/2022] [Indexed: 11/04/2022]
Abstract
BACKGROUND Cardiovascular disease (CVD) remains the main cause of death in patients with type 2 diabetes (T2D). Although hyperuricemia has been associated with multiple CV complications, it is not officially recognized as a target parameter for CVD risk reduction. AIM To systematically review the literature in order to determine whether treating hyperuricemia with allopurinol in patients with T2D reduces CVD risk. METHODS A thorough literature search in the PubMed, CENTRAL, and EMBASE databases from inception to August 2022 was performed. After application of selection criteria, 6 appropriate studies were identified. RESULTS Detailed analysis of the data derived indicated that there is an association between allopurinol treatment and CV benefits, resulting in a reduced risk of CVD events and mortality rates. This association can be attributed mainly to the reduction of inflammation and oxidative burden, as well as to the improvement of glycemic and lipid profiles. CONCLUSIONS This systematic review provides evidence that allopurinol may reduce CVD risk in patients with T2D. Randomized, placebo-controlled trials should be performed in order to confirm these findings and identify specific subgroups of patients who will benefit most.
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Affiliation(s)
- Evanthia Bletsa
- 3rd Department of Cardiology, School of Medicine, Sotiria Chest Disease Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Stavroula A Paschou
- Endocrine Unit and Diabetes Centre, Department of Clinical Therapeutics, School of Medicine, Alexandra Hospital, National and Kapodistrian University of Athens, 80 Vasilisis Sophias Ave, 11528, Athens, Greece.
| | - Vasiliki Tsigkou
- 3rd Department of Cardiology, School of Medicine, Sotiria Chest Disease Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Panagiota K Stampouloglou
- 3rd Department of Cardiology, School of Medicine, Sotiria Chest Disease Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | | | - Georgia N Kassi
- Department of Endocrinology, Alexandra Hospital, Athens, Greece
| | - Evangelos Oikonomou
- 3rd Department of Cardiology, School of Medicine, Sotiria Chest Disease Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Gerasimos Siasos
- 3rd Department of Cardiology, School of Medicine, Sotiria Chest Disease Hospital, National and Kapodistrian University of Athens, Athens, Greece
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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Abstract
INTRODUCTION Gout is the most common form of inflammatory arthritis affecting millions of people around the world. Painful flares and tophaceous deposits can be debilitating, reducing quality of life among those affected and putting strain on health care systems. AREAS COVERED This review provides an overview of the treatment of gout for flare pain management and lowering serum urate. Firstline agents are discussed with emphasis on emerging evidence. Novel therapies are also covered. EXPERT OPINION Lifestyle modifications form a part of gout prevention. Regarding gout flare pharmacotherapy NSAIDs, colchicine and glucocorticoids are first line agents. The IL-1β antagonists also are highly effective for arresting flares but their cost-effectiveness render them as salvage therapies. Allopurinol is an agent of first choice for urate lowering therapy (ULT). In South East Asian and Black populations screening for HLA*B58:01 mutation is a cost-effective approach to decrease the occurrence of the rare but potentially very serious allopurinol hypersensitivity syndrome (AHS.). Febuxostat is another efficacious urate lowering therapy but it has received U.S. FDA black box warning for cardiovascular safety and careful consideration is warranted before its initiation in patients with high cardiovascular risk. Novel uricosurics are a class for continued drug development; verinurad and arhalofenate are agents with future promise. For patients with recalcitrant gout, pegloticase is another effective option in the rheumatologist's armamentarium. Its immunogenicity significantly threatens the achievement of sustained urate lowering responses. Abrogating pegloticase's immunogenicity with immunomodulatory co-therapy may lend to sustained efficacy.
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Affiliation(s)
- K E G Blake
- Clinical Fellow, Division of Clinical Immunology and Rheumatology, The University of Alabama at Birmingham, 1720 2nd Ave South, FOT 839. Birmingham, AL 35294-3408
| | - Jordan L Saag
- Medical Student, University of Central Florida College of Medicine, 6850 Lake Nona Blvd. Orlando, FL 32827
| | - Kenneth G Saag
- Director, Division of Clinical Immunology and Rheumatology, The University of Alabama at Birmingham, 1720 2nd Ave South, FOT 839. Birmingham, AL 35294-3408
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Toroghi MK, Cluett WR, Mahadevan R. A Personalized Multiscale Modeling Framework for Dose Selection in Precision Medicine. Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.0c01070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Masood Khaksar Toroghi
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada, M5S 3E5
| | - William R. Cluett
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada, M5S 3E5
| | - Radhakrishnan Mahadevan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada, M5S 3E5
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada, M5S 3E5
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11
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Abstract
Allopurinol, a first line urate-lowering therapy, has been associated with serious cutaneous reactions that have a high mortality. A number of risk factors for these serious adverse reactions have been identified including ethnicity, HLA-B∗5801 genotype, kidney impairment, allopurinol starting dose, and concomitant diuretic use. There is a complex interplay between these risk factors, which may (albeit rarely) lead to allopurinol-related serious adverse events. Although oxypurinol, the active metabolite of allopurinol, has been implicated, there is no defined drug concentration at which the reaction will occur. There is no specific treatment other than the cessation of allopurinol and supportive care. Whether hemodialysis, which rapidly removes oxypurinol, improves outcomes remains to be determined. Strategies to help reduce this risk are therefore important, which includes screening for HLA-B∗5801 in high-risk individuals, commencing allopurinol at low dose, and educating patients about the signs and symptoms of severe cutaneous adverse reactions, and what to do if they occur.
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Park HJ, Yun J, Kang DY, Park JW, Koh YI, Kim S, Kim SH, Nam YH, Jeong YY, Kim CW, Park HK, Kim SH, Kang HR, Jung JW. Unique Clinical Characteristics and Prognosis of Allopurinol-Induced Severe Cutaneous Adverse Reactions. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2019; 7:2739-2749.e3. [DOI: 10.1016/j.jaip.2019.05.047] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/12/2019] [Accepted: 05/25/2019] [Indexed: 12/17/2022]
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Stamp LK, Chapman PT, Barclay M, Horne A, Frampton C, Merriman TR, Wright DFB, Drake J, Dalbeth N. Relationships Between Allopurinol Dose, Oxypurinol Concentration and Urate-Lowering Response-In Search of a Minimum Effective Oxypurinol Concentration. Clin Transl Sci 2019; 13:110-115. [PMID: 31444839 PMCID: PMC6951452 DOI: 10.1111/cts.12686] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 07/24/2019] [Indexed: 11/26/2022] Open
Abstract
The aims of this study were to determine factors that predict serum urate (SU) lowering response to allopurinol and the conversion of allopurinol to oxypurinol, and to determine a minimum therapeutic oxypurinol concentration. Data from 129 participants in a 24-month open, randomized, controlled, parallel-group, comparative clinical trial were analyzed. Allopurinol dose, SU, and plasma oxypurinol concentrations were available at multiple time points. The slope for the association between allopurinol dose and SU was calculated as a measure of sensitivity to allopurinol. The slope for the association between allopurinol dose and oxypurinol was calculated as a measure of allopurinol metabolism. Receiver operating characteristic (ROC) curves were used to identify a minimum oxypurinol concentration predictive of SU < 6 mg/dL. There was a wide range of SU concentrations for each allopurinol dose. The relationship between sensitivity to allopurinol and allopurinol metabolism for each 100 mg allopurinol dose increase varied between individuals. Body mass index (P = 0.023), creatinine clearance (CrCL; P = 0.037), ABCG2 Q141K (P = 0.019), and SU (P = 0.004) were associated with sensitivity to allopurinol. The minimum oxypurinol concentration for achieving the urate target was found to be about 104 μmol/L, but predictive accuracy was poor (ROC curve area under the curve (AUC) 0.65). The minimum therapeutic oxypurinol concentration was found to increase with decreasing renal function. Although there is a positive relationship between change in oxypurinol and change in SU concentration, a minimum therapeutic oxypurinol is dependent on CrCL and cannot reliably predict SU target. Other variables, including ABCG2 Q141K genotype, impact on sensitivity to allopurinol (ACTRN12611000845932).
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Affiliation(s)
- Lisa K Stamp
- Department of Medicine, University of Otago, Christchurch, New Zealand.,Department of Rheumatology, Immunology, and Allergy, Christchurch Hospital, Christchurch, New Zealand
| | - Peter T Chapman
- Department of Rheumatology, Immunology, and Allergy, Christchurch Hospital, Christchurch, New Zealand
| | - Murray Barclay
- Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Anne Horne
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | | | - Tony R Merriman
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | | | - Jill Drake
- Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Nicola Dalbeth
- Department of Medicine, University of Auckland, Auckland, New Zealand
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15
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Ultra-performance hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry for simultaneous determination of allopurinol, oxypurinol and lesinurad in rat plasma: Application to pharmacokinetic study in rats. PLoS One 2019; 14:e0213786. [PMID: 30870504 PMCID: PMC6417734 DOI: 10.1371/journal.pone.0213786] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 03/01/2019] [Indexed: 02/05/2023] Open
Abstract
A fixed dose combination of lesinurad and allopurinol has been recently approved by USFDA and EMA for treatment of gout-associated hyperuricemia in patients who have not achieved target serum uric acid levels with allopurinol alone. In this study, an ultra-performance hydrophilic interaction liquid chromatography (UPHILIC) coupled with tandem mass spectrometry method was developed and validated for simultaneous determination of allopurinol, oxypurinol and lesinurad in rat plasma. Liquid liquid extraction using ethyl acetate as extracting agent was used for samples extraction procedure. Acquity UPLC HILIC column (100 mm x 2.1, 1.7μm) was used for separation of allopurinol, oxypurinol, lesinurad and internal standard (5-Florouracil). The mobile phase consisting of acetonitrile, water and formic acid (95:5:0.1, v/v/v), were eluted at 0.3 mL/min flow rate having total chromatographic run time of 3 min per sample. The analytes were detected on Acquity triple quadrupole mass spectrometer equipped with a Z-Spray electrospray ionization (ESI). The ESI source was operated in negative mode and multiple reaction monitoring was used for ion transition for all compounds. The precursor to product ion transition of m/z 134.94 > 64.07 for allopurinol, 150.89 > 41.91 for oxypurinol, 401.90 > 176.79 for lesinurad and 128.85 >41.92 for internal standard were used for identification and quantification. The calibration curves for all analytes were found to be linear with weighing factor of 1/x2 using regression analysis. The developed assay was successfully applied in an oral pharmacokinetic study of allopurinol, oxypurinol and lesinurad in rats.
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16
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Stamp LK, Wallace M, Roberts RL, Frampton C, Miner JN, Merriman TR, Dalbeth N. ABCG2 rs2231142 (Q141K) and oxypurinol concentrations in people with gout receiving allopurinol. Drug Metab Pharmacokinet 2018; 33:241-242. [PMID: 30274827 DOI: 10.1016/j.dmpk.2018.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 08/26/2018] [Accepted: 09/05/2018] [Indexed: 12/14/2022]
Affiliation(s)
- Lisa K Stamp
- Department of Medicine, University of Otago, Christchurch, PO Box 4345, New Zealand.
| | - Mary Wallace
- Department of Surgical Sciences, University of Otago, PO Box 56, Dunedin, New Zealand
| | - Rebecca L Roberts
- Department of Surgical Sciences, University of Otago, PO Box 56, Dunedin, New Zealand
| | - Christopher Frampton
- Department of Medicine, University of Otago, Christchurch, PO Box 4345, New Zealand
| | - Jeffrey N Miner
- Viscentio Bio 3550 General Atomics Court, San Diego, CA, 92121, USA
| | - Tony R Merriman
- Department of Biochemistry, University of Otago, PO Box 56, Dunedin, New Zealand
| | - Nicola Dalbeth
- Department of Medicine, University of Auckland, 85 Park Rd, Grafton, Auckland, 1023, New Zealand
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Hirai T, Itoh T, Kimura T, Echizen H. Evaluation of a pharmacokinetic-pharmacodynamic model for hypouricaemic effects of febuxostat using datasets obtained from real-world patients. Br J Clin Pharmacol 2018; 84:2260-2269. [PMID: 29876951 DOI: 10.1111/bcp.13666] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 05/16/2018] [Accepted: 05/27/2018] [Indexed: 01/24/2023] Open
Abstract
AIM Febuxostat is an active xanthine oxidase (XO) inhibitor which is widely used in the treatment of hyperuricaemia. We aimed to evaluate the predictive performance of a pharmacokinetic-pharmacodynamic (PK-PD) model of the hypouricaemic effects of febuxostat. METHODS Previously, we formulated a PK-PD model for predicting the hypouricaemic effects of febuxostat as a function of baseline serum urate levels, body weight, renal function and drug dose, using datasets reported in preapproval studies. Using an updated model with a sensitivity analysis, we examined the predictive performance of the PK-PD model, using datasets obtained from the medical records of patients who received febuxostat from March 2011 to December 2015 at Tokyo Women's Medical University Hospital. Multivariate regression analysis was performed to explore clinical variables to improve the predictive performance of the model. RESULTS A total of 1199 serum urate values were retrieved from 168 patients (age: 60.5 ± 17.7 years; 71.4% male) who were receiving febuxostat as a treatment for hyperuricaemia. There was a significant correlation (r = 0.68; P < 0.01) between the serum urate levels observed and those predicted by the modified PK-PD model. A multivariate regression analysis revealed that the predictive performance of the model could be improved further by considering comorbidities (such as diabetes mellitus), estimated glomerular filtration rate (eGFR) and the coadministration of loop diuretics (r = 0.77, P < 0.01). CONCLUSIONS The PK-PD model may be useful for predicting individualized maintenance doses of febuxostat in real-world patients.
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Affiliation(s)
- Toshinori Hirai
- Department of Pharmacy, Tokyo Women's Medical University Medical Center East, 2-1-10, Nishiogu, Arakawa-ku, Tokyo, 116-8567, Japan
| | - Toshimasa Itoh
- Department of Pharmacy, Tokyo Women's Medical University Medical Center East, 2-1-10, Nishiogu, Arakawa-ku, Tokyo, 116-8567, Japan
| | - Toshimi Kimura
- Department of Pharmacy, Tokyo Women's Medical University Hospital, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Hirotoshi Echizen
- Department of Pharmacotherapy, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan
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Wright DFB, Dalbeth N, Phipps-Green AJ, Merriman TR, Barclay ML, Drake J, Tan P, Horne A, Stamp LK. The impact of diuretic use and ABCG2 genotype on the predictive performance of a published allopurinol dosing tool. Br J Clin Pharmacol 2018; 84:937-943. [PMID: 29341237 DOI: 10.1111/bcp.13516] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 12/31/2017] [Accepted: 01/09/2018] [Indexed: 01/12/2023] Open
Abstract
AIM This research aims to evaluate the predictive performance of a published allopurinol dosing tool. METHODS Allopurinol dose predictions were compared to the actual dose required to achieve serum urate (SU) <0.36 mmol l-1 using mean prediction error. The influence of patient factors on dose predictions was explored using multilinear regression. RESULTS Allopurinol doses were overpredicted by the dosing tool; however, this was minimal in patients without diuretic therapy (MPE 63 mg day-1 , 95% CI 40-87) compared to those receiving diuretics (MPE 295 mg day-1 , 95% CI 260-330, P < 0.0001). ABCG2 genotype (rs2231142, G>T) had an important impact on the dose predictions (MPE 201, 107, 15 mg day-1 for GG, GT and TT, respectively, P < 0.0001). Diuretic use and ABCG2 genotype explained 53% of the variability in prediction error (R2 = 0.53, P = 0.0004). CONCLUSIONS The dosing tool produced acceptable maintenance dose predictions for patients not taking diuretics. Inclusion of ABCG2 genotype and a revised adjustment for diuretics would further improve the performance of the dosing tool.
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Affiliation(s)
| | - Nicola Dalbeth
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | | | - Tony R Merriman
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Murray L Barclay
- Department of Medicine, University of Otago, Christchurch, New Zealand.,Department of Clinical Pharmacology, Christchurch Hospital, Christchurch, New Zealand
| | - Jill Drake
- Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Paul Tan
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Anne Horne
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Lisa K Stamp
- Department of Medicine, University of Otago, Christchurch, New Zealand
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Bredemeier M, Lopes LM, Eisenreich MA, Hickmann S, Bongiorno GK, d’Avila R, Morsch ALB, da Silva Stein F, Campos GGD. Xanthine oxidase inhibitors for prevention of cardiovascular events: a systematic review and meta-analysis of randomized controlled trials. BMC Cardiovasc Disord 2018; 18:24. [PMID: 29415653 PMCID: PMC5804046 DOI: 10.1186/s12872-018-0757-9] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 01/23/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Xanthine oxidase inhibitors (XOI), classified as purine-like (allopurinol and oxypurinol) and non-purine (febuxostat and topiroxostat) XOI, present antioxidant properties by reducing the production of reactive oxygen species derived from purine metabolism. Oxidative stress is an important factor related to endothelial dysfunction and ischemia-reperfusion injury, and may be implicated in the pathogenesis of heart failure, hypertension, and ischemic heart disease. However, there is contradictory evidence regarding the possible cardiovascular (CV) protective effect exerted by XOI. Our objective is to compare the incidence of major adverse cardiovascular events (MACE), mortality, total (TCE) and specific CV events in randomized controlled trials (RCTs) testing XOI against placebo or no treatment. METHODS PubMed, EMBASE, Web of Science, Cochrane Central, Lilacs databases were searched from inception to Dec 30 2016, along with hand searching. RCTs including exclusively adult individuals, lasting ≥ 4 weeks, with no language restriction, were eligible. Independent paired researchers selected studies and extracted data. Considering the expected rarity of events, Peto and DerSimonian/Laird odds ratios (OR), the latter in case of heterogeneity, were used for analysis. Random-effects meta-regression was used to explore heterogeneity. RESULTS The analysis of MACE included 81 articles (10,684 patients, 6434 patient-years). XOI did not significantly reduce risk of MACE (ORP = 0.71, 95% CI 0.46-1.09) and death (0.89, 0.59-1.33), but reduced risk of TCE (0.60, 0.44-0.82; serious TCE: 0.64, 0.46 to 0.89), and hypertension (0.54, 0.37 to 0.80). There was protection for MACE in patients with previous ischemic events (0.42, 0.23-0.76). Allopurinol protected for myocardial infarction (0.38, 0.17-0.83), hypertension (0.32, 0.18-0.58), TCE (0.48, 0.31 to 0.75, I2 = 55%) and serious TCE (0.56, 0.36 to 0.86, I2 = 44%). Meta-regression associated increasing dose of allopurinol with higher risk of TCE and serious TCE (P < 0.05). Accordingly, lower doses (≤ 300 mg/day) of allopurinol reduced the risk of TCE, unlike higher doses. Non-purine-like XOI did not significantly reduce or increase the risk of adverse CV events, but confidence intervals were wide. Quality of evidence was generally low to moderate. CONCLUSIONS Purine-like XOI may reduce the incidence of adverse CV outcomes. However, higher doses of allopurinol (> 300 mg/day) may be associated with loss of CV protection.
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Affiliation(s)
- Markus Bredemeier
- Rheumatology Service at Hospital Nossa Senhora da Conceição, Grupo Hospitalar Conceição, Porto Alegre, RS Brazil
- Serviço de Reumatologia do Hospital Nossa Senhora da Conceição, Avenida Francisco Trein, 596, sala 2048, Porto Alegre, RS 91350-200 Brazil
| | - Lediane Moreira Lopes
- Rheumatology Service at Hospital Nossa Senhora da Conceição, Grupo Hospitalar Conceição, Porto Alegre, RS Brazil
| | - Matheus Augusto Eisenreich
- Rheumatology Service at Hospital Nossa Senhora da Conceição, Grupo Hospitalar Conceição, Porto Alegre, RS Brazil
| | - Sheila Hickmann
- Rheumatology Service at Hospital Nossa Senhora da Conceição, Grupo Hospitalar Conceição, Porto Alegre, RS Brazil
| | - Guilherme Kopik Bongiorno
- Rheumatology Service at Hospital Nossa Senhora da Conceição, Grupo Hospitalar Conceição, Porto Alegre, RS Brazil
| | - Rui d’Avila
- Rheumatology Service at Hospital Nossa Senhora da Conceição, Grupo Hospitalar Conceição, Porto Alegre, RS Brazil
| | | | - Fernando da Silva Stein
- Rheumatology Service at Hospital Nossa Senhora da Conceição, Grupo Hospitalar Conceição, Porto Alegre, RS Brazil
| | - Guilherme Gomes Dias Campos
- Rheumatology Service at Hospital Nossa Senhora da Conceição, Grupo Hospitalar Conceição, Porto Alegre, RS Brazil
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20
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Stamp LK, Barclay ML. How to prevent allopurinol hypersensitivity reactions? Rheumatology (Oxford) 2017; 57:i35-i41. [DOI: 10.1093/rheumatology/kex422] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Indexed: 12/13/2022] Open
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21
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Kannangara DRW, Graham GG, Wright DFB, Stocker SL, Portek I, Pile KD, Barclay ML, Williams KM, Stamp LK, Day RO. Individualising the dose of allopurinol in patients with gout. Br J Clin Pharmacol 2017; 83:2015-2026. [PMID: 28417592 DOI: 10.1111/bcp.13307] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 03/14/2017] [Accepted: 04/04/2017] [Indexed: 12/01/2022] Open
Abstract
AIMS The aims of the study were to: 1) determine if a plasma oxypurinol concentration-response relationship or an allopurinol dose-response relationship best predicts the dose requirements of allopurinol in the treatment of gout; and 2) to construct a nomogram for calculating the optimum maintenance dose of allopurinol to achieve target serum urate (SU) concentrations. METHODS A nonlinear regression analysis was used to examine the plasma oxypurinol concentration- and allopurinol dose-response relationships with serum urate. In 81 patients (205 samples), creatinine clearance (CLCR ), concomitant diuretic use and SU concentrations before (UP ) and during (UT ) treatment were monitored across a range of allopurinol doses (D, 50-700 mg daily). Plasma concentrations of oxypurinol (C) were measured in 47 patients (98 samples). Models (n = 47 patients) and predictions from each relationship were compared using F-tests, r2 values and paired t-tests. The best model was used to construct a nomogram. RESULTS The final plasma oxypurinol concentration-response relationship (UT = UP - C*(UP - UR )/(ID50 + C), r2 = 0.64) and allopurinol dose-response relationship (UT = UP - D* (UP - UR )/(ID50 + D), r2 = 0.60) did not include CLCR or diuretic use as covariates. There was no difference (P = 0.87) between the predicted SU concentrations derived from the oxypurinol concentration- and allopurinol dose-response relationships. The nomogram constructed using the allopurinol dose-response relationship for all recruited patients (n = 81 patients) required pretreatment SU as the predictor of allopurinol maintenance dose. CONCLUSIONS Plasma oxypurinol concentrations, CLCR and diuretic status are not required to predict the maintenance dose of allopurinol. Using the nomogram, the maintenance dose of allopurinol estimated to reach target concentrations can be predicted from UP .
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Affiliation(s)
- Diluk R W Kannangara
- Department of Clinical Pharmacology & Toxicology, St Vincent's Hospital, Sydney, Australia.,School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Garry G Graham
- Department of Clinical Pharmacology & Toxicology, St Vincent's Hospital, Sydney, Australia.,School of Medical Sciences, University of New South Wales, Sydney, Australia
| | | | - Sophie L Stocker
- Department of Clinical Pharmacology & Toxicology, St Vincent's Hospital, Sydney, Australia.,School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Ian Portek
- Department of Rheumatology, St George Hospital, Sydney, Australia
| | - Kevin D Pile
- Department of Medicine, Western Sydney University, Campbelltown, Australia
| | - Murray L Barclay
- Department of Medicine, University of Otago, Christchurch, New Zealand.,Department of Clinical Pharmacology, Christchurch Hospital, Christchurch, New Zealand
| | - Kenneth M Williams
- Department of Clinical Pharmacology & Toxicology, St Vincent's Hospital, Sydney, Australia.,School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Lisa K Stamp
- Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Richard O Day
- Department of Clinical Pharmacology & Toxicology, St Vincent's Hospital, Sydney, Australia.,School of Medical Sciences, University of New South Wales, Sydney, Australia.,St Vincent's Clinical School, University of New South Wales, Sydney, Australia
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Day RO, Kannangara DR, Stocker SL, Carland JE, Williams KM, Graham GG. Allopurinol: insights from studies of dose–response relationships. Expert Opin Drug Metab Toxicol 2016; 13:449-462. [DOI: 10.1080/17425255.2017.1269745] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Richard O. Day
- Department of Clinical Pharmacology & Toxicology, St Vincent’s Hospital, Darlinghurst, Sydney, Australia
- St Vincent’s Clinical School, UNSW Australia, Darlinghurst, Sydney, Australia
| | - Diluk R.W. Kannangara
- Department of Clinical Pharmacology & Toxicology, St Vincent’s Hospital, Darlinghurst, Sydney, Australia
- St Vincent’s Clinical School, UNSW Australia, Darlinghurst, Sydney, Australia
| | - Sophie L. Stocker
- Department of Clinical Pharmacology & Toxicology, St Vincent’s Hospital, Darlinghurst, Sydney, Australia
- School of Medical Sciences, UNSW Australia, Kensington, Sydney, Australia
| | - Jane E. Carland
- Department of Clinical Pharmacology & Toxicology, St Vincent’s Hospital, Darlinghurst, Sydney, Australia
- School of Medical Sciences, UNSW Australia, Kensington, Sydney, Australia
| | - Kenneth M. Williams
- Department of Clinical Pharmacology & Toxicology, St Vincent’s Hospital, Darlinghurst, Sydney, Australia
- School of Medical Sciences, UNSW Australia, Kensington, Sydney, Australia
| | - Garry G. Graham
- Department of Clinical Pharmacology & Toxicology, St Vincent’s Hospital, Darlinghurst, Sydney, Australia
- School of Medical Sciences, UNSW Australia, Kensington, Sydney, Australia
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Wright DFB, Doogue MP, Barclay ML, Chapman PT, Cross NB, Irvine JH, Stamp LK. A population pharmacokinetic model to predict oxypurinol exposure in patients on haemodialysis. Eur J Clin Pharmacol 2016; 73:71-78. [DOI: 10.1007/s00228-016-2133-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 09/09/2016] [Indexed: 01/22/2023]
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Hmar RC, Kannangara DRW, Ramasamy SN, Baysari MT, Williams KM, Day RO. Understanding and improving the use of allopurinol in a teaching hospital. Intern Med J 2016; 45:383-90. [PMID: 25644128 DOI: 10.1111/imj.12701] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 01/25/2015] [Indexed: 11/29/2022]
Abstract
BACKGROUND An emphasis on renal function in deciding maintenance doses of allopurinol to prevent allopurinol hypersensitivity has resulted in ineffective prevention of attacks of gout. New therapeutic guidelines for gout have shifted the focus back to titrating maintenance doses to reach a serum uric acid (SUA) concentration target of ≤ 0.36 mmol/L. AIMS To examine trends in the prescribing of allopurinol in a teaching hospital and their concordance with the new guidelines for gout management, and to explore prescribers' approaches and attitudes to the use of allopurinol. METHODS An audit was conducted of all inpatients prescribed allopurinol at a teaching hospital between January 2008 and December 2012. Allopurinol dose, SUA, serum creatinine concentrations and estimated glomerular filtration rates were extracted from the hospital databases. Doctors from medical units who regularly prescribed allopurinol were interviewed. RESULTS The allopurinol dose prescribed in gout patients most commonly was a continuation of the pre-admission dosage. Dosage change during admission was rarely observed. Dosages reflected a consideration of renal function. SUA concentrations were measured in only 21% (n = 269) of gout patients. Prescriber interviews (n = 12) reflected adequate knowledge regarding allopurinol use, but most maintained that the primary care setting was more suitable for the management of dose titration in gout. CONCLUSIONS SUA concentrations were not routinely measured in the majority of admitted gout patients taking allopurinol. Without SUA measurements and allopurinol dose titration, patients with SUA > 0.36 mmol/L are at increased risk for acute attacks of gout in hospital.
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Affiliation(s)
- R C Hmar
- Department of Clinical Pharmacology and Toxicology, St Vincent's Hospital, Sydney, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, Sydney, New South Wales, Australia
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25
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Wright DFB, Duffull SB, Merriman TR, Dalbeth N, Barclay ML, Stamp LK. Predicting allopurinol response in patients with gout. Br J Clin Pharmacol 2015; 81:277-89. [PMID: 26451524 DOI: 10.1111/bcp.12799] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 09/25/2015] [Accepted: 10/03/2015] [Indexed: 12/11/2022] Open
Abstract
AIMS The primary aim of this research was to predict the allopurinol maintenance doses required to achieve the target plasma urate of ≤0.36 mmol l(-1) . METHODS A population analysis was conducted in nonmem using oxypurinol and urate plasma concentrations from 133 gout patients. Maintenance dose predictions to achieve the recommended plasma urate target were generated. RESULTS The urate response was best described by a direct effects model. Renal function, diuretic use and body size were found to be significant covariates. Dose requirements increased approximately 2-fold over a 3-fold range of total body weight and were 1.25-2 fold higher in those taking diuretics. Renal function had only a modest impact on dose requirements. CONCLUSIONS Contrary to current guidelines, the model predicted that allopurinol dose requirements were determined primarily by differences in body size and diuretic use. A revised guide to the likely allopurinol doses to achieve the target plasma urate concentration is proposed.
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Affiliation(s)
| | | | | | - Nicola Dalbeth
- Department of Medicine, University of Auckland, Auckland
| | - Murray L Barclay
- Department of Medicine, University of Otago, Christchurch.,Department of Clinical Pharmacology, Christchurch Hospital, Christchurch, New Zealand
| | - Lisa K Stamp
- Department of Medicine, University of Otago, Christchurch
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26
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Stamp LK, Day RO, Yun J. Allopurinol hypersensitivity: investigating the cause and minimizing the risk. Nat Rev Rheumatol 2015; 12:235-42. [PMID: 26416594 DOI: 10.1038/nrrheum.2015.132] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Allopurinol is the most commonly prescribed urate-lowering therapy for the management of gout. Serious adverse reactions associated with allopurinol, while rare, are feared owing to the high mortality. Such reactions can manifest as a rash combined with eosinophilia, leukocytosis, fever, hepatitis and progressive kidney failure. Risk factors for allopurinol-related severe adverse reactions include the recent introduction of allopurinol, the presence of the HLA-B(*)58:01 allele, and factors that influence the drug concentration. The interactions between allopurinol, its metabolite, oxypurinol, and T cells have been studied, and evidence exists that the presence of the HLA-B(*)58:01 allele and a high concentration of oxypurinol function synergistically to increase the number of potentially immunogenic-peptide-oxypurinol-HLA-B(*)58:01 complexes on the cell surface, thereby increasing the risk of T-cell sensitization and a subsequent adverse reaction. This Review will discuss the above issues and place this in the clinical context of reducing the risk of serious adverse reactions.
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Affiliation(s)
- Lisa K Stamp
- Department of Medicine, University of Otago, Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand
| | - Richard O Day
- Department of Clinical Pharmacology &Toxicology, St Vincent's Hospital, Darlinghurst, NSW 2010, Australia
| | - James Yun
- Department of Clinical Immunology and Allergy, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
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27
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Management of gout and hyperuricemia. Rheumatology (Oxford) 2015. [DOI: 10.1016/b978-0-323-09138-1.00189-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Abstract
BACKGROUND Allopurinol, a xanthine oxidase inhibitor, is considered one of the most effective urate-lowering drugs and is frequently used in the treatment of chronic gout. OBJECTIVES To assess the efficacy and safety of allopurinol compared with placebo and other urate-lowering therapies for treating chronic gout. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE on 14 January 2014. We also handsearched the 2011 to 2012 American College of Rheumatology (ACR) and European League against Rheumatism (EULAR) abstracts, trial registers and regulatory agency drug safety databases. SELECTION CRITERIA All randomised controlled trials (RCTs) or quasi-randomised controlled clinical trials (CCTs) that compared allopurinol with a placebo or an active therapy in adults with chronic gout. DATA COLLECTION AND ANALYSIS We extracted and analysed data using standard methods for Cochrane reviews. The major outcomes of interest were frequency of acute gout attacks, serum urate normalisation, pain, function, tophus regression, study participant withdrawal due to adverse events (AE) and serious adverse events (SAE). We assessed the quality of the body of evidence for these outcomes using the GRADE approach. MAIN RESULTS We included 11 trials (4531 participants) that compared allopurinol (various doses) with placebo (two trials); febuxostat (four trials); benzbromarone (two trials); colchicine (one trial); probenecid (one trial); continuous versus intermittent allopurinol (one trial) and different doses of allopurinol (one trial). Only one trial was at low risk of bias in all domains. We deemed allopurinol versus placebo the main comparison, and allopurinol versus febuxostat and versus benzbromarone as the most clinically relevant active comparisons and restricted reporting to these comparisons here.Moderate-quality evidence from one trial (57 participants) indicated allopurinol 300 mg daily probably does not reduce the rate of gout attacks (2/26 with allopurinol versus 3/25 with placebo; risk ratio (RR) 0.64, 95% confidence interval (CI) 0.12 to 3.52) but increases the proportion of participants achieving a target serum urate over 30 days (25/26 with allopurinol versus 0/25 with placebo, RR 49.11, 95% CI 3.15 to 765.58; number needed to treat for an additional beneficial outcome (NNTB) 1). In two studies (453 participants), there was no significant increase in withdrawals due to AE (6% with allopurinol versus 4% with placebo, RR 1.36, 95% CI 0.61 to 3.08) or SAE (2% with allopurinol versus 1% with placebo, RR 1.93, 95% CI 0.48 to 7.80). One trial reported no difference in pain reduction or tophus regression, but did not report outcome data or measures of variance sufficiently and we could not calculate the differences between groups. Neither trial reported function.Low-quality evidence from three trials (1136 participants) indicated there may be no difference in the incidence of acute gout attacks with allopurinol up to 300 mg daily versus febuxostat 80 mg daily over eight to 24 weeks (21% with allopurinol versus 23% with febuxostat, RR 0.89, 95% CI 0.71 to 1.1); however more participants may achieve target serum urate level (four trials; 2618 participants) with febuxostat 80 mg daily versus allopurinol 300 mg daily (38% with allopurinol versus 70% with febuxostat, RR 0.56, 95% CI 0.48 to 0.65, NNTB with febuxostat 4). Two trials reported no difference in tophus regression between allopurinol and febuxostat over a 28- to 52-week period; but as the trialists did not provide variance, we could not calculate the mean difference between groups. The trials did not report pain reduction or function. Moderate-quality evidence from pooled data from three trials (2555 participants) comparing allopurinol up to 300 mg daily versus febuxostat 80 mg daily indicated no difference in the number of withdrawals due to AE (7% with allopurinol versus 8% with febuxostat, RR 0.89, 95% CI 0.62 to 1.26) or SAE (4% with allopurinol versus 4% with febuxostat, RR 1.13, 95% CI 0.71 to 1.82) over a 24- to 52-week period.Low-quality evidence from one trial (65 participants) indicated there may be no difference in the incidence of acute gout attacks with allopurinol up to 600 mg daily compared with benzbromarone up to 200 mg daily over a four-month period (0/30 with allopurinol versus 1/25 with benzbromarone, RR 0.28, 95% CI 0.01 to 6.58). Based on the pooled results of two trials (102 participants), there was moderate-quality evidence of no probable difference in the proportion of participants achieving a target serum urate level with allopurinol versus benzbromarone (58% with allopurinol versus 74% with benzbromarone, RR 0.79, 95% CI 0.56 to 1.11). Low-quality evidence from two studies indicated there may be no difference in the number of participants who withdrew due to AE with allopurinol versus benzbromarone over a four- to nine-month period (6% with allopurinol versus 7% with benzbromarone, pooled RR 0.80, 95% CI 0.18 to 3.58). There were no SAEs. They did not report tophi regression, pain and function.All other comparisons were supported by small, single studies only, limiting conclusions. AUTHORS' CONCLUSIONS Our review found low- to moderate-quality evidence indicating similar effects on withdrawals due to AEs and SAEs and incidence of acute gout attacks when allopurinol (100 to 600 mg daily) was compared with placebo, benzbromarone (100 to 200 mg daily) or febuxostat (80 mg daily). There was moderate-quality evidence of little or no difference in the proportion of participants achieving target serum urate when allopurinol was compared with benzbromarone. However, allopurinol seemed more successful than placebo and may be less successful than febuxostat (80 mg daily) in achieving a target serum urate level (6 mg/dL or less; 0.36 mmol/L or less) based on moderate- to low-quality evidence. Single studies reported no difference in pain reduction when allopurinol (300 mg daily) was compared with placebo over 10 days, and no difference in tophus regression when allopurinol (200 to 300 mg daily) was compared with febuxostat (80 mg daily). None of the trials reported on function, health-related quality of life or participant global assessment of treatment success, where further research would be useful.
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Affiliation(s)
- Rakhi Seth
- University Hospital Southampton NHS Foundation TrustDepartment of RheumatologySouthamptonUK
| | - Alison SR Kydd
- University of British ColumbiaDivision of Rheumatology1650 Terminal Ave, Suite 206NanaimoBCCanadaV9S 0A3
| | - Rachelle Buchbinder
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash UniversityMonash Department of Clinical Epidemiology, Cabrini HospitalSuite 41, Cabrini Medical Centre183 Wattletree RoadMalvernVictoriaAustralia3144
| | - Claire Bombardier
- Institute for Work & Health481 University Avenue, Suite 800TorontoONCanadaM5G 2E9
| | - Christopher J Edwards
- University Hospital Southampton NHS Foundation TrustDepartment of RheumatologySouthamptonUK
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Stamp LK, Barclay M. Therapeutic drug monitoring in rheumatic diseases: utile or futile? Rheumatology (Oxford) 2014; 53:988-97. [PMID: 24196384 DOI: 10.1093/rheumatology/ket355] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Rapid and effective suppression of inflammation is a primary goal in the treatment of rheumatic diseases. However, the therapeutic effect of most medications may be slow to manifest, in the order of weeks or months in the case of DMARDs. Monitoring of drug concentrations allows the possibility of appropriate dose adjustment or changes in medication to achieve more rapid or better outcomes. We review the evidence for drug concentration monitoring. Despite the theoretical utility for monitoring of MTX polyglutamate concentrations in red blood cells in patients with RA, studies have not shown a clear association between concentrations and either efficacy or toxicity and routine measurement is not yet recommended. Small studies associating disease control with concentrations of anti-TNF therapies and anti-drug antibodies suggest that routine monitoring may be useful in the future. However, the data are not yet sufficient for this recommendation. With the use of allopurinol in gout, there is a putative therapeutic range for the active metabolite oxypurinol; however, adjusting the allopurinol dose to achieve a target urate concentration is likely to be most effective, and measuring oxypurinol may be best suited to assessing drug adherence. Although measuring thiopurine metabolite concentrations with AZA therapy has been shown to be useful in IBD, studies in rheumatic diseases have so far failed to confirm a useful association between concentrations and disease control or drug toxicity. Whole blood concentrations of HCQ have been associated with disease control in SLE and future studies may be able to determine a therapeutic range.
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Chung WH, Chang WC, Stocker SL, Juo CG, Graham GG, Lee MHH, Williams KM, Tian YC, Juan KC, Jan Wu YJ, Yang CH, Chang CJ, Lin YJ, Day RO, Hung SI. Insights into the poor prognosis of allopurinol-induced severe cutaneous adverse reactions: the impact of renal insufficiency, high plasma levels of oxypurinol and granulysin. Ann Rheum Dis 2014; 74:2157-64. [PMID: 25115449 DOI: 10.1136/annrheumdis-2014-205577] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 07/26/2014] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Allopurinol, an antihyperuricaemic agent, is one of the common causes of life-threatening severe cutaneous adverse reactions (SCAR), including drug rash with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS) and toxic epidermal necrosis (TEN). The prognostic factors for allopurinol-related SCAR remain unclear. This study aimed to investigate the relationship of dosing, renal function, plasma levels of oxypurinol and granulysin (a cytotoxic protein of SJS/TEN), the disease severity and mortality in allopurinol-SCAR. METHODS We prospectively enrolled 48 patients with allopurinol-SCAR (26 SJS/TEN and 22 DRESS) and 138 allopurinol-tolerant controls from 2007 to 2012. The human leucocyte antigen (HLA)-B*58:01 status, plasma concentrations of oxypurinol and granulysin were determined. RESULTS In this cohort, HLA-B*58:01 was strongly associated with allopurinol-SCAR (p<0.001, OR (95% CI) 109 (25 to 481)); however, the initial/maintenance dosages showed no relationship with the disease. Poor renal function was significantly associated with the delayed clearance of plasma oxypurinol, and increased the risk of allopurinol-SCAR (p<0.001, OR (95% CI) 8.0 (3.9 to 17)). Sustained high levels of oxypurinol after allopurinol withdrawal correlated with the poor prognosis of allopurinol-SCAR. In particular, the increased plasma levels of oxypurinol and granulysin linked to the high mortality of allopurinol-SJS/TEN (p<0.01), and strongly associated with prolonged cutaneous reactions in allopurinol-DRESS (p<0.05). CONCLUSIONS Impaired renal function and increased plasma levels of oxypurinol and granulysin correlated with the poor prognosis of allopurinol-SCAR. Allopurinol prescription is suggested to be avoided in subjects with renal insufficiency and HLA-B*58:01 carriers. An early intervention to increase the clearance of plasma oxypurinol may improve the prognosis of allopurinol-SCAR.
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Affiliation(s)
- Wen-Hung Chung
- Department of Dermatology, Keelung Chang Gung Memorial Hospital, Keelung, Taiwan Department of Dermatology, Drug Hypersensitivity Clinical and Research Center, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Wan-Chun Chang
- Institute of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Sophie L Stocker
- Department of Clinical Pharmacology & Toxicology, St. Vincent's Hospital, Sydney, New South Wales, Australia St Vincent's Hospital Clinical School and School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Chiun-Gung Juo
- Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan
| | - Garry G Graham
- Department of Clinical Pharmacology & Toxicology, St. Vincent's Hospital, Sydney, New South Wales, Australia St Vincent's Hospital Clinical School and School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Ming-Han H Lee
- Department of Clinical Pharmacology & Toxicology, St. Vincent's Hospital, Sydney, New South Wales, Australia St Vincent's Hospital Clinical School and School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Kenneth M Williams
- Department of Clinical Pharmacology & Toxicology, St. Vincent's Hospital, Sydney, New South Wales, Australia St Vincent's Hospital Clinical School and School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Ya-Chung Tian
- College of Medicine, Chang Gung University, Taoyuan, Taiwan Department of Nephrology, Kidney Research Center, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan
| | - Kuo-Chang Juan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan Department of Nephrology, Kidney Research Center, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan
| | - Yeong-Jian Jan Wu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan Division of Allergy, Immunology and Rheumatology, Department of Medicine, Chang Gung Memorial Hospital, Keelung, Taiwan
| | - Chih-Hsun Yang
- Department of Dermatology, Drug Hypersensitivity Clinical and Research Center, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chee-Jen Chang
- Graduate Institute of Clinical Medical Science, Clinical Informatics and Medical Statistics Research Center, Chang Gung University, Taoyuan, Taiwan Biostatistical Center for Clinical Research, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Yu-Jr Lin
- Graduate Institute of Clinical Medical Science, Clinical Informatics and Medical Statistics Research Center, Chang Gung University, Taoyuan, Taiwan Biostatistical Center for Clinical Research, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Richard O Day
- Department of Clinical Pharmacology & Toxicology, St. Vincent's Hospital, Sydney, New South Wales, Australia St Vincent's Hospital Clinical School and School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Shuen-Iu Hung
- Institute of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
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Stamp LK, Turner R, Khalilova IS, Zhang M, Drake J, Forbes LV, Kettle AJ. Myeloperoxidase and oxidation of uric acid in gout: implications for the clinical consequences of hyperuricaemia. Rheumatology (Oxford) 2014; 53:1958-65. [PMID: 24899662 DOI: 10.1093/rheumatology/keu218] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVES The aims of this study were to establish whether, in patients with gout, MPO is released from neutrophils and urate is oxidized to allantoin and if these effects are attenuated by allopurinol. METHODS MPO, urate, allantoin and oxypurinol were measured in plasma from 54 patients with gout and 27 healthy controls. Twenty-three patients had acute gout, 13 of whom were receiving allopurinol, and 31 had intercritical gout, 20 of whom were receiving allopurinol. Ten additional gout patients had samples collected before and after 4 weeks of allopurinol. RESULTS Plasma MPO and its specific activity were higher (P < 0.05) in patients with acute gout not receiving allopurinol compared with controls. MPO protein in patients' plasma was related to urate concentration (r = 0.5, P < 0.001). Plasma allantoin was higher (P < 0.001) in all patient groups compared with controls. In controls and patients not receiving allopurinol, allantoin was associated with plasma urate (r = 0.62, P < 0.001) and MPO activity (r = 0.45, P < 0.002). When 10 patients were treated with allopurinol, it lowered their plasma urate and allantoin (P = 0.002). In all patients receiving allopurinol, plasma allantoin was related to oxypurinol (r = 0.65, P < 0.0001). Oxypurinol was a substrate for purified MPO that enhanced the oxidation of urate. CONCLUSION Increased concentrations of urate in gout lead to the release of MPO from neutrophils and the oxidation of urate. Products of MPO and reactive metabolites of urate may contribute to the pathology of gout and hyperuricaemia. At low concentrations, oxypurinol should reduce inflammation, but high concentrations may contribute to oxidative stress.
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Affiliation(s)
- Lisa K Stamp
- Department of Medicine, Department of Pathology, Centre for Free Radical Research, University of Otago, and Clinical Pharmacology Canterbury Health Laboratories, Christchurch, New Zealand
| | - Rufus Turner
- Department of Medicine, Department of Pathology, Centre for Free Radical Research, University of Otago, and Clinical Pharmacology Canterbury Health Laboratories, Christchurch, New Zealand
| | - Irada S Khalilova
- Department of Medicine, Department of Pathology, Centre for Free Radical Research, University of Otago, and Clinical Pharmacology Canterbury Health Laboratories, Christchurch, New Zealand
| | - Mei Zhang
- Department of Medicine, Department of Pathology, Centre for Free Radical Research, University of Otago, and Clinical Pharmacology Canterbury Health Laboratories, Christchurch, New Zealand
| | - Jill Drake
- Department of Medicine, Department of Pathology, Centre for Free Radical Research, University of Otago, and Clinical Pharmacology Canterbury Health Laboratories, Christchurch, New Zealand
| | - Louisa V Forbes
- Department of Medicine, Department of Pathology, Centre for Free Radical Research, University of Otago, and Clinical Pharmacology Canterbury Health Laboratories, Christchurch, New Zealand
| | - Anthony J Kettle
- Department of Medicine, Department of Pathology, Centre for Free Radical Research, University of Otago, and Clinical Pharmacology Canterbury Health Laboratories, Christchurch, New Zealand.
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Stamp LK, Merriman TR, Barclay ML, Singh JA, Roberts RL, Wright DFB, Dalbeth N. Impaired response or insufficient dosage? Examining the potential causes of "inadequate response" to allopurinol in the treatment of gout. Semin Arthritis Rheum 2014; 44:170-4. [PMID: 24925693 DOI: 10.1016/j.semarthrit.2014.05.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 04/06/2014] [Accepted: 05/02/2014] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Gout is one of the most common forms of arthritis. It is well established that urate-lowering therapy that aims for a serum urate less than at least 0.36 mmol/l (6 mg/dl) is required for the successful management of gout. Allopurinol, a xanthine oxidase (XO) inhibitor, is the most commonly used urate-lowering therapy. However, many patients fail to achieve the target serum urate on allopurinol; these patients can be considered to have "inadequate response" to allopurinol. Herein, we examine the potential mechanisms and implications of inadequate response to allopurinol. METHODS The literature was reviewed for potential causes for failure to reach target serum urate in patients receiving allopurinol. RESULTS The two most common causes of inadequate response to allopurinol are poor adherence and under-dosing of allopurinol. Adherent patients who fail to achieve target serum urate on standard doses of allopurinol form a group that could be considered to be "partially resistant" to allopurinol. There are four potential mechanisms for partial allopurinol resistance: decreased conversion of allopurinol to oxypurinol; increased renal excretion of oxypurinol; abnormality in XO structure and/or function such that oxypurinol is rendered less effective and/or drug interactions. CONCLUSIONS It is important to determine the reasons for failure to achieve treatment targets with allopurinol, particularly as newer agents become available. The knowledge of the mechanisms for inadequate response may help guide the clinician towards making a therapeutic choice that is more likely to result in achieving the serum urate target.
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Affiliation(s)
- Lisa K Stamp
- Department of Medicine, University of Otago, Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand.
| | - Tony R Merriman
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Murray L Barclay
- Department of Clinical Pharmacology, Christchurch Hospital, Christchurch, New Zealand
| | - Jasvinder A Singh
- Medicine Service, Birmingham VA Medical Center, Birmingham, AL; Rheumatology Division, University of Alabama, Birmingham, AL
| | - Rebecca L Roberts
- Department of Surgical Sciences, University of Otago, Dunedin, New Zealand
| | | | - Nicola Dalbeth
- Department of Medicine, University of Auckland, Auckland, New Zealand
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Kaandorp JJ, van den Broek MPH, Benders MJNL, Oudijk MA, Porath MM, Bambang Oetomo S, Wouters MGAJ, van Elburg R, Franssen MTM, Bos AF, Mol BWJ, Visser GHA, van Bel F, Rademaker CMA, Derks JB. Rapid target allopurinol concentrations in the hypoxic fetus after maternal administration during labour. Arch Dis Child Fetal Neonatal Ed 2014; 99:F144-8. [PMID: 24352085 DOI: 10.1136/archdischild-2013-304876] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE Perinatal hypoxia-induced free radical formation is an important cause of hypoxic-ischaemic encephalopathy and subsequent neurodevelopmental disabilities. Allopurinol reduces the formation of free radicals, which potentially limits hypoxia-induced brain damage. We investigated placental transfer and safety of allopurinol after maternal allopurinol treatment during labour to evaluate its potential role as a neuroprotective agent in suspected fetal hypoxia. DESIGN We used data from a randomised, double-blind multicentre trial comparing maternal allopurinol versus placebo in case of imminent fetal hypoxia (NCT00189007). PATIENTS We studied 58 women in labour at term, with suspected fetal hypoxia prompting immediate delivery, in the intervention arm of the study. SETTING Delivery rooms of 11 Dutch hospitals. INTERVENTION 500 mg allopurinol, intravenously to the mother, immediately prior to delivery. MAIN OUTCOME MEASURES Drug disposition (maternal plasma concentrations, cord blood concentrations) and drug safety (maternal and fetal adverse events). RESULTS Within 5 min after the end of maternal allopurinol infusion, target plasma concentrations of allopurinol of ≥2 mg/L were present in cord blood. Of all analysed cord blood samples, 95% (52/55) had a target allopurinol plasma concentration at the moment of delivery. No adverse events were observed in the neonates. Two mothers had a red and/or painful arm during infusion. CONCLUSIONS A dose of 500 mg intravenous allopurinol rapidly crosses the placenta and provides target concentrations in 95% of the fetuses at the moment of delivery, which makes it potentially useful as a neuroprotective agent in perinatology with very little side effects. TRIAL REGISTRATION The study is registered in the Dutch Trial Register (NTR1383) and the Clinical Trials protocol registration system (NCT00189007).
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Affiliation(s)
- J J Kaandorp
- Department of Perinatology, University Medical Centre, , Utrecht, The Netherlands
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An audit of a therapeutic drug monitoring service for allopurinol therapy. Ther Drug Monit 2013; 35:863-6. [PMID: 24263644 DOI: 10.1097/ftd.0b013e318299920a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Oxypurinol, the active metabolite of allopurinol, is the major determinant of the hypouricemic effect of allopurinol. Monitoring oxypurinol concentrations is undertaken to determine adherence to therapy, to investigate reasons for continuing attacks of acute gout and/or insufficiently low plasma urate concentrations despite allopurinol treatment, and to assess the risk of allopurinol hypersensitivity, an adverse effect that has been putatively associated with elevated plasma oxypurinol concentrations. METHODS An audit of request forms requesting plasma oxypurinol concentration measurements received by the pathology service (SydPath) at St Vincent's Hospital, Darlinghurst, Sydney was undertaken for the 7-year period January 2005-December 2011. Patient demographics, biochemical data, including plasma creatinine and uric acid concentrations, comorbidities, and concomitant medications were recorded. RESULTS There were 412 requests for determination of an oxypurinol concentration. On 48% of occasions, the time of allopurinol dosing was recorded, while just 79 (19%) blood samples were collected 6-9 hours postdosing, the time window used to establish the therapeutic range for oxypurinol. For these optimally interpretable concentrations, 32 (8%) were within the putative therapeutic range (5-15 mg/L), while 5 (1%) were below and 41 (10%) above this range. The daily dose of allopurinol was documented on only one-third of the request forms. Individually, plasma urate and creatinine concentrations were requested concomitantly with plasma oxypurinol concentrations in 66% and 58% of the cases, respectively; while plasma oxypurinol, urate, and creatinine concentrations were requested concomitantly in 49% of the cases. CONCLUSIONS Requesting clinicians and blood specimen collectors often fail to provide relevant information (dose, times of last dose, and blood sample collection) to allow the most useful interpretation of oxypurinol concentrations. Concomitant plasma urate and creatinine concentrations should be requested to allow more complete interpretation of the data.
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Ramasamy SN, Korb-Wells CS, Kannangara DRW, Smith MWH, Wang N, Roberts DM, Graham GG, Williams KM, Day RO. Allopurinol Hypersensitivity: A Systematic Review of All Published Cases, 1950–2012. Drug Saf 2013; 36:953-80. [DOI: 10.1007/s40264-013-0084-0] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Wright DFB, Stamp LK, Merriman TR, Barclay ML, Duffull SB, Holford NHG. The population pharmacokinetics of allopurinol and oxypurinol in patients with gout. Eur J Clin Pharmacol 2013; 69:1411-21. [DOI: 10.1007/s00228-013-1478-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Accepted: 02/02/2013] [Indexed: 11/28/2022]
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Hershfield MS, Callaghan JT, Tassaneeyakul W, Mushiroda T, Thorn CF, Klein TE, Lee MTM. Clinical Pharmacogenetics Implementation Consortium guidelines for human leukocyte antigen-B genotype and allopurinol dosing. Clin Pharmacol Ther 2013; 93:153-8. [PMID: 23232549 PMCID: PMC3564416 DOI: 10.1038/clpt.2012.209] [Citation(s) in RCA: 152] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 10/04/2012] [Indexed: 01/11/2023]
Abstract
Allopurinol is the most commonly used drug for the treatment of hyperuricemia and gout. However, allopurinol is also one of the most common causes of severe cutaneous adverse reactions (SCARs), which include drug hypersensitivity syndrome, Stevens–Johnson syndrome, and toxic epidermal necrolysis. A variant allele of the human leukocyte antigen (HLA)-B, HLA-B*58:01, associates strongly with allopurinolinduced SCAR. We have summarized the evidence from the published literature and developed peer-reviewed guidelines for allopurinol use based on HLA-B genotype.
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Affiliation(s)
- M S Hershfield
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina, USA
| | - J T Callaghan
- ACOS for Research, Department of Veterans Affairs Medical Center, Indianapolis, Indiana, USA
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Pharmacology/Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - W Tassaneeyakul
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - T Mushiroda
- Laboratory for Pharmacogenetics, RIKEN Center for Genomic Medicine, Yokohama, Japan
| | - C F Thorn
- Department of Genetics, Stanford University Medical Center, Stanford, California, USA
| | - T E Klein
- Department of Genetics, Stanford University Medical Center, Stanford, California, USA
| | - M T M Lee
- National Center for Genome Medicine, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
- School of Chinese Medicine, China Medical University, Taichung, Taiwan
- Laboratory for International Alliance, RIKEN Center for Genomic Medicine, Yokohama, Japan
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Stocker SL, McLachlan AJ, Savic RM, Kirkpatrick CM, Graham GG, Williams KM, Day RO. The pharmacokinetics of oxypurinol in people with gout. Br J Clin Pharmacol 2013; 74:477-89. [PMID: 22300439 DOI: 10.1111/j.1365-2125.2012.04207.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
AIMS Our aim was to identify and quantify the sources of variability in oxypurinol pharmacokinetics and explore relationships with plasma urate concentrations. METHODS Non-linear mixed effects modelling was applied to concentration-time data from 155 gouty patients with demographic, medical history and renal transporter genotype information. RESULTS A one compartment pharmacokinetic model with first order absorption best described the oxypurinol concentration-time data. Renal function and concomitant medicines (diuretics and probenecid), but not transporter genotype, significantly influenced oxypurinol pharmacokinetics and reduced the between subject variability in the apparent clearance of oxypurinol (CL/F(m)) from 65% to 29%. CL/F(m) for patients with normal, mild, moderate and severe renal impairment was 1.8, 0.6, 0.3 and 0.18 l h(-1), respectively. Model predictions showed a relationship between plasma oxypurinol and urate concentrations and failure to reach target oxypurinol concentrations using suggested allopurinol dosing guidelines. CONCLUSIONS In conclusion, this first established pharmacokinetic model provides a tool to achieve target oxypurinol plasma concentrations, thereby optimizing the effectiveness and safety of allopurinol therapy in gouty patients with various degrees of renal impairment.
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Sundy JS. The rheumatology of gout. Adv Chronic Kidney Dis 2012; 19:404-12. [PMID: 23089276 DOI: 10.1053/j.ackd.2012.07.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 07/24/2012] [Indexed: 11/11/2022]
Abstract
Gout is a metabolic disorder of purine metabolism with primary manifestations of acute and chronic arthritis and tophus formation. The prevalence of gout appears to be increasing and may affect up to 8 million people in the United States. The development of novel therapies for gout after a 40-year hiatus has opened new understanding of this disease. In addition to causing severe musculoskeletal pain, gout is associated with impaired quality of life, reduced functional status, and injury to joints. The quality of care for many patients with gout is unfortunately not in keeping with current guidelines. The approval of new therapies to treat hyperuricemia, such as febuxostat and pegloticase, has increased our knowledge of the challenges of adequately controlling the disease. Rather than providing a comprehensive overview of gout, this review focuses on new developments in the clinical aspects of gout and highlights advances in the drug therapy of gout.
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Pérez-Mazliah D, Albareda MC, Alvarez MG, Lococo B, Bertocchi GL, Petti M, Viotti RJ, Laucella SA. Allopurinol reduces antigen-specific and polyclonal activation of human T cells. Front Immunol 2012; 3:295. [PMID: 23049532 PMCID: PMC3448060 DOI: 10.3389/fimmu.2012.00295] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 09/04/2012] [Indexed: 11/13/2022] Open
Abstract
Allopurinol is the most popular commercially available xanthine oxidase inhibitor and it is widely used for treatment of symptomatic hyperuricaemia, or gout. Although, several anti-inflammatory actions of allopurinol have been demonstrated in vivo and in vitro, there have been few studies on the action of allopurinol on T cells. In the current study, we have assessed the effect of allopurinol on antigen-specific and mitogen-driven activation and cytokine production in human T cells. Allopurinol markedly decreased the frequency of IFN-γ and IL-2-producing T cells, either after polyclonal or antigen-specific stimulation with Herpes Simplex virus 1, Influenza (Flu) virus, tetanus toxoid and Trypanosoma cruzi-derived antigens. Allopurinol attenuated CD69 upregulation after CD3 and CD28 engagement and significantly reduced the levels of spontaneous and mitogen-induced intracellular reactive oxygen species in T cells. The diminished T cell activation and cytokine production in the presence of allopurinol support a direct action of allopurinol on human T cells, offering a potential pharmacological tool for the management of cell-mediated inflammatory diseases.
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Affiliation(s)
- Damián Pérez-Mazliah
- Instituto Nacional de Parasitología "Dr. Mario Fatala Chaben" Ciudad Autónoma de Buenos Aires, Argentina
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Keenan RT. Safety of urate-lowering therapies: managing the risks to gain the benefits. Rheum Dis Clin North Am 2012; 38:663-80. [PMID: 23137576 DOI: 10.1016/j.rdc.2012.08.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Gout is a metabolic disorder of purine metabolism and uric acid elimination. Over time, acute gout can develop into a chronic, disabling arthropathy, often associated with multiple comorbidities. Gout patients have often been undertreated, partly because of the clinician's perceived risks of a therapy outweighing its potential benefits. The approval of new therapies to treat hyperuricemia in gout has led to a new understanding of gout management and medication safety regarding new and old therapies. This review focuses on potential safety issues of currently available urate-lowering therapies and outlines strategies to minimize risks so their benefits can be reached.
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Affiliation(s)
- Robert T Keenan
- Duke Gout and Crystal Arthropathies Clinic, Duke Specialty Infusion Center, Durham, NC 27710, USA.
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Stamp LK, Taylor WJ, Jones PB, Dockerty JL, Drake J, Frampton C, Dalbeth N. Starting dose is a risk factor for allopurinol hypersensitivity syndrome: A proposed safe starting dose of allopurinol. ACTA ACUST UNITED AC 2012; 64:2529-36. [DOI: 10.1002/art.34488] [Citation(s) in RCA: 203] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Stamp LK, Barclay ML, O'Donnell JL, Zhang M, Drake J, Frampton C, Chapman PT. Furosemide increases plasma oxypurinol without lowering serum urate--a complex drug interaction: implications for clinical practice. Rheumatology (Oxford) 2012; 51:1670-6. [DOI: 10.1093/rheumatology/kes091] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Improving the use of allopurinol in chronic gout: monitoring oxypurinol levels to guide therapy. Clin Pharmacol Ther 2011; 90:363-4. [PMID: 21862966 DOI: 10.1038/clpt.2011.146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Urate-lowering therapy (ULT), adjusted to achieve and maintain a serum uric acid (SUA) of <6 mg/dl, remains the standard of care for the chronic management of gout. New urate-lowering medications are important options; however, these agents should be reserved for patients who do not tolerate or cannot achieve SUA <6 mg/dl on allopurinol. The result of oxypurinol monitoring to guide allopurinol therapy suggests that allopurinol should still be considered first-line ULT for gout.
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