The effects of non-steroidal anti-inflammatory drugs on the disposition of methotrexate in patients with rheumatoid arthritis

Polymeric Microneedles Enhance Transdermal Delivery of Therapeutics

This research presents the efficacy of polymeric microneedles in improving the transdermal permeation of methotrexate across human skin. These microneedles were fabricated from PLGA Expansorb® 50-2A and 50-8A and subjected to comprehensive characterization via scanning electron microscopy, Fourier-transform infrared spectroscopy, and mechanical analysis. We developed and assessed a methotrexate hydrogel for physicochemical and rheological properties. Dye binding, histological examinations, and assessments of skin integrity demonstrated the effective microporation of the skin by PLGA microneedles. We measured the dimensions of microchannels in the skin using scanning electron microscopy, pore uniformity analysis, and confocal microscopy. The skin permeation and disposition of methotrexate were researched in vitro. PLGA 50-8A microneedles appeared significantly longer, sharper, and more mechanically uniform than PLGA 50-2A needles. PLGA 50-8A needles generated substantially more microchannels, as well as deeper, larger, and more uniform channels in the skin than PLGA 50-2A needles. Microneedle insertion substantially reduced skin electrical resistance, accompanied by an elevation in transepidermal water loss values. PLGA 50-8A microneedle treatment provided a significantly higher cumulative delivery, flux, diffusion coefficient, permeability coefficient, and predicted steady-state plasma concentration; however, there was a shorter lag time than for PLGA 50-2A needles, base-treated, and untreated groups (p < 0.05). Conclusively, skin microporation using polymeric microneedles significantly improved the transdermal delivery of methotrexate.

A critical review of methotrexate clinical interactions: role of transporters

INTRODUCTION

Methotrexate (MTX) is an anti-folate and immunosuppressive drug prescribed for various malignancies and immune diseases. However, delayed elimination of MTX associated with concomitant use of some medications can lead to severe and life-threatening adverse effects.

AREAS COVERED

This paper investigated drug-MTX interactions that lead to elevated MTX levels and related adverse effects due to the role of transporters. Methotrexate toxicity occurs at both low and high doses administrations. According to the studies we reviewed in this paper, most interaction records with methotrexate occurred with co-administration of indomethacin, ketoprofen, omeprazole, piperacillin/tazobactam, ciprofloxacin, co-trimoxazole, probenecid, and imatinib, mainly due to the role of transporters. However, most studies were performed as case reports or series, and confirming the exact drug-methotrexate interaction still needs further clinical investigations.

EXPERT OPINION

Our findings showed no firm evidence of interactions of proton pump inhibitors (PPIs), levetiracetam, and NSAIDS with MTX. Moreover, patients' risk factors, hypoalbuminemia, renal failure, third space fluid retention, the elderly, polypharmacy, and transport inhibition are the most critical factors for MTX toxicity. If substitution or temporary discontinuation is not possible, healthcare providers should be aware of interactions, especially in patients with risk factors for MTX toxicity.

A Natural Plant Ingredient, Menthone, Regulates T Cell Subtypes and Lowers Pro-inflammatory Cytokines of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease with nearly 1.6 billion patients worldwide and an incidence of 0.5-1%. In recent years, basic and clinical studies have revealed that immune cell responses and corresponding secretion of inflammatory factors are important in the control of RA development. Our study found that a natural plant ingredient, menthone, could be used as a potential antirheumatism compound. In vivo observations demonstrated that menthone alleviates collagen II-induced arthritis (CIA) in mice. Furthermore, we found that menthone regulates the number of Th1 and Th17 cells in CIA mice. Importantly, menthone significantly inhibits the release of pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6, in CIA mice. Our study suggests a potential component for the development of drugs to treat rheumatoid arthritis.

Two cases of severe neutropenia in patients on low-dose methotrexate and ceftriaxone

PURPOSE

There are limited data on the effect of ceftriaxone on methotrexate clearance, with results of some studies indicating altered methotrexate pharmacokinetics with the administration of ceftriaxone. We describe 2 possible cases demonstrating an interaction between methotrexate and ceftriaxone, resulting in profound neutropenia.

SUMMARY

The decision to continue methotrexate therapy in the setting of surgery or during treatment of an active infection continues to be a topic of debate due to perceived negative effects on the healing process. Methotrexate is typically administered at a lower dose for inflammatory arthritis than for hematologic indications, thus having less immunosuppression potential. However, if methotrexate is continued during treatment of infection, drug interactions along with effects on the healing process should be considered. Ceftriaxone is commonly considered safe for long-term therapy due to its favorable adverse effect and drug interaction profile. Ceftriaxone is partially eliminated via organic anion transporters in the kidneys, leading to potential competition with methotrexate clearance in the renal tubules. Clinicians using these drugs concurrently should be aware of the potential for development of neutropenia and monitor patients receiving this combination closely.

CONCLUSION

Two patients receiving ceftriaxone therapy in the setting of a joint infection developed profound neutropenia after resuming oral methotrexate therapy for inflammatory arthritis.

Intra-articular injection of indomethacin-methotrexate in situ hydrogel for the synergistic treatment of rheumatoid arthritis

Rheumatoid arthritis is a chronic systemic autoimmune disease that causes joint swelling and cartilage damage. The objective of the present work was to develop a temperature-sensitive hydrogel (D-NGel) containing nanoparticles (D-NPs), which could simultaneously deliver combination indomethacin and methotrexate. D-NPs were formed by multiple non-covalent interactions between PEI-SS and the carboxyl-containing hydrophobic small molecule drugs IND and MTX, which were then loaded into a temperature-sensitive hydrogel matrix. The T_sol/gel of the temperature-sensitive hydrogel matrix composed of 27% F127 and 10% F68 was 33 °C and the gelation time was less than 15 s. The resultant D-NGel was injected into the articular cavity of collagen-induced arthritis rats and quickly transformed in situ into gels which slowly released drug in the joint fluid for up to 72 h. The D-NGel effectively reduced joint swelling, bone erosion and expression of inflammatory cytokines in the ankle fluid and knee joint fluid. In addition, liver and kidney function tests and histopathological examination indicated there was a good biological safety for D-NGel. In conclusion, this work has demonstrated the great potential of the D-NGel for sustained co-delivery of IND and MTX for the synergistic treatment of rheumatoid arthritis, treating both the symptoms and the root causes of rheumatoid arthritis.

Electrically and Ultrasonically Enhanced Transdermal Delivery of Methotrexate

In this study, we used sonophoresis and iontophoresis to enhance the in vitro delivery of methotrexate through human cadaver skin. Iontophoresis was applied for 60 min at a 0.4 mA/sq·cm current density, while low-frequency sonophoresis was applied at a 20 kHz frequency (2 min application, and 6.9 W/sq·cm intensity). The treated skin was characterized by dye binding, transepidermal water loss, skin electrical resistance, and skin temperature measurement. Both sonophoresis and iontophoresis resulted in a significant reduction in skin electrical resistance as well as a marked increase in transepidermal water loss value (p < 0.05). Furthermore, the ultrasonic waves resulted in a significant increase in skin temperature (p < 0.05). In permeation studies, the use of iontophoresis led to a significantly higher drug permeability than the untreated group (n = 4, p < 0.05). The skin became markedly more permeable to methotrexate after the treatment by sonophoresis than by iontophoresis (p < 0.01). A synergistic effect for the combined application of sonophoresis and iontophoresis was also observed. Drug distribution in the skin layers revealed a significantly higher level of methotrexate in the sonicated skin than that in iontophoresis and untreated groups. Iontophoresis and low-frequency sonophoresis were found to enhance the transdermal and intradermal delivery of methotrexate in vitro.

Interaction Between Low-Dose Methotrexate and Nonsteroidal Anti-inflammatory Drugs, Penicillins, and Proton Pump Inhibitors

Objective: To review the potential drug interactions between low-dose methotrexate (LD-MTX) and nonsteroidal anti-inflammatory drugs (NSAIDs), penicillins, and proton-pump inhibitors (PPIs) given the disparity between interactions reported for high-dose and low-dose MTX to help guide clinicians. Data Sources: A literature search was performed in MEDLINE (1946 to September 2016), EMBASE (1974 to September 2016), and International Pharmaceutical Abstracts (1970 to January 2015) to identify reports describing potential drug interactions between LD-MTX and NSAIDS, penicillins, or PPIs. Reference lists of included articles were reviewed to find additional eligible articles. Study Selection and Data Extraction: All English-language observational, randomized, and pharmacokinetic (PK) studies assessing LD-MTX interactions in humans were analyzed to determine clinical relevance in making recommendations to clinicians. Clinical case reports were assigned a Drug Interaction Probability Scale score. Data Synthesis: A total of 32 articles were included (28 with NSAIDs, 3 with penicillins, and 2 with PPIs [1 including both PPI and NSAID]). Although there are some PK data to describe increased LD-MTX concentrations when NSAIDs are used concomitantly, the clinical relevance remains unclear. Based on the limited data on LD-MTX with penicillins and PPIs, no clinically meaningful interaction was identified. Conclusion: Given the available evidence, the clinical importance of the interaction between LD-MTX and NSAIDs, penicillins, and PPIs cannot be substantiated. Health care providers should assess the benefit and risk of LD-MTX regardless of concomitant drug use, including factors known to predispose patients to MTX toxicity, and continue to monitor clinical and laboratory parameters per guideline recommendations.

Uncertainty and variability in human exposure limits - a chemical-specific approach for ciprofloxacin and methotrexate

Human exposure limits (HELs) for chemicals with a toxicological threshold are traditionally derived using default assessment factors that account for variations in exposure duration, species sensitivity and individual sensitivity. The present paper elaborates a probabilistic approach for human hazard characterization and the derivation of HELs. It extends the framework for evaluating and expressing uncertainty in hazard characterization recently proposed by WHO-IPCS, i.e. by the incorporation of chemical-specific data on human variability in toxicokinetics. The incorporation of human variability in toxicodynamics was based on the variation between adverse outcome pathways (AOPs). Furthermore, sources of interindividual variability and uncertainty are propagated separately throughout the derivation process. The outcome is a two-dimensional human dose distribution that quantifies the population fraction exceeding a pre-selected critical effect level with an estimate of the associated uncertainty. This enables policy makers to set separate standards for the fraction of the population to be protected and the confidence level of the assessment. The main sources of uncertainty in the human dose distribution can be identified in order to plan new research for reducing uncertainty. Additionally, the approach enables quantification of the relative risk for specific subpopulations. The approach is demonstrated for two pharmaceuticals, i.e. the antibiotic ciprofloxacin and the antineoplastic methotrexate. For both substances, the probabilistic HEL is mainly influenced by uncertainty originating from: (1) the point of departure (PoD), (2) extrapolation from sub-acute to chronic toxicity and (3) interspecies extrapolation. However, when assessing the tails of the two-dimensional human dose distributions, i.e. the section relevant for the derivation of human exposure limits, interindividual variability in toxicodynamics also becomes important.

Drug safety: The concept, inception and its importance in patients' health

BACKGROUND

Drug safety is one of the hottest topics in daily medical practice, particularly with regard to approving new medication or questioning the possibility of withdrawing a drug from the market.

AIM

The aim of this review is to highlight the importance of the drug safety concept and its impact on patients' health.

METHODS

A literature search was conducted using Pubmed®, EMBASE®, EBSCO and Medline in the period between 1980 and 2013. The terms used in the search included "Drug Safety", "Medication Safety", "Patient Safety", "Drug Interaction", "Drug Pharmacokinetic", and "Adverse Drug Reaction". All retrieved abstracts were evaluated within the context of the review objectives. The full texts of the selected articles were included in this review. Studies in non-English language were excluded in this review.

RESULTS

Since the early days of the past century, many acts, laws, or amendments have been created to make sure that approved drugs are first safe and then effective. Furthermore, these regulations are continuing to change to make sure that these drugs have a positive benefit-risk balance. Personalized medicine should be considered when medications are given to patients because the pharmacokinetic process inside the body varies from patient to patient and from one specific disease state to another. However, adverse drug reactions can be minimized if more precautions are taken by healthcare professionals, especially including the patient as one pillar of the therapeutic plan and providing more patient counseling, which will improve drug safety.

CONCLUSION

The drug safety concept has earned a lot of attention during the past decade due to the fact it plays a major role in patients' health. Recent laws stress this concept should be included in the process of new medications' approval and continued conduct of post-marketing drug evaluations. Benefit-risk assessment should be considered by all health care professionals when they need to give specific drugs to specific groups of patients. Therefore, more care should be given to some patients, such as pregnant women, children and the elderly, since they are considered vulnerable populations.

Coadministration of Lansoprazole and Naproxen Does Not Affect the Pharmacokinetic Profile of Methotrexate in Adult Patients With Rheumatoid Arthritis

Drugs prescribed for rheumatoid arthritis are often associated with gastrointestinal toxicity, and proton pump inhibitors may be coadministered for gastroprotection. In this open-label study, the effect of lansoprazole 30 mg qd and naproxen 500 mg bid on the pharmacokinetic profile of methotrexate was investigated. Twenty-seven adult rheumatoid arthritis patients on stable oral methotrexate doses (7.5-15 mg/week) for a minimum of 3 months were enrolled. Methotrexate pharmacokinetics were assessed on days -1 (methotrexate alone) and 7 (methotrexate with lansoprazole and naproxen). Pharmacokinetics of methotrexate and 7-hydroxymethotrexate were not altered by coadministration of methotrexate with lansoprazole and naproxen; point estimates and 90% confidence intervals for the peak plasma concentration and area under the plasma concentration-time curve of methotrexate and 7-hydroxymethotrexate were within the 0.80 to 1.25 boundaries. Therefore, coadministration of naproxen and lansoprazole for 7 days does not affect the pharmacokinetic profile of low doses of methotrexate.

Effect of ketoprofen and indomethacin on methotrexate pharmacokinetics in mice plasma and tumor tissues

Methotrexate (MTX) has been used in combination with nonsteroidal anti-inflammatory drugs in the treatment of inflammatory diseases as well as malignancies. Severe adverse effects with this combination may occur, usually resulting from inhibition of renal transporters. Solid Ehrlich carcinoma was experimentally induced by implantation of Ehrlich ascites Carcinoma cells subcutaneously into the thigh of mice, and after 30 days, mice were divided into three groups: Group I that served as control group received MTX (50 mg/kg, i.p.); Group II received ketoprofen (100 mg/kg, i.p.) and then after half an hour received MTX (50 mg/kg, i.p.); Group III received indomethacin (10 mg/kg, i.p.) and then after half an hour received MTX (50 mg/kg, i.p.). Plasma and tissue samples were collected at different time points and then MTX concentrations were determined by HPLC. The injection of ketoprofen or indomethacin before MTX injection resulted in significant increase in the AUC and CPmax of MTX (p < 0.05) and significant decrease in CL/F and Vd/F of MTX (p < 0.05) in mice plasma. The effects were more significant after injection of indomethacin than in case of ketoprofen. The study showed that administration of ketoprofen or indomethacin prior to MTX caused significant decrease in MTX elimination and significant increase in MTX extent of absorption which may lead to severe adverse effects if coadministered in human.

Safety of non-steroidal anti-inflammatory drugs, including aspirin and paracetamol (acetaminophen) in people receiving methotrexate for inflammatory arthritis (rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, other spondyloarthritis)

BACKGROUND

Methotrexate is routinely used in the treatment of inflammatory arthritis. There have been concerns regarding the safety of using concurrent non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin, or paracetamol (acetaminophen), or both, in these people.

OBJECTIVES

To systematically appraise and summarise the scientific evidence on the safety of using NSAIDs, including aspirin, or paracetamol, or both, with methotrexate in inflammatory arthritis; and to identify gaps in the current evidence, assess the implications of those gaps and to make recommendations for future research to address these deficiencies.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, second quarter 2010); MEDLINE (from 1950); EMBASE (from 1980); the Cochrane Database of Systematic Reviews (CDSR) and the Database of Abstracts of Reviews of Effects (DARE). We also handsearched the conference proceedings for the American College of Rheumatology (ACR) and European League against Rheumatism (EULAR) (2008 to 2009) and checked the websites of regulatory agencies for reported adverse events, labels and warnings.

SELECTION CRITERIA

Randomised controlled trials and non-randomised studies comparing the safety of methotrexate alone to methotrexate with concurrent NSAIDs, including aspirin, or paracetamol, or both, in people with inflammatory arthritis.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the search results, extracted data and assessed the risk of bias of the included studies.

MAIN RESULTS

Seventeen publications out of 8681 identified studies were included in the review, all of which included people with rheumatoid arthritis using various NSAIDs, including aspirin. There were no identified studies for other forms of inflammatory arthritis.For NSAIDs, 13 studies were included that used concurrent NSAIDs, of which nine studies examined unspecified NSAIDs. The mean number of participants was 150.4 (range 19 to 315), mean duration 2182.9 (range 183 to 5490) days, although the study duration was not always clearly defined, and the studies were mainly of low to moderate quality. Two of these studies reported no evidence for increased risk of methotrexate-induced pulmonary disease; one study assessed the effect of concurrent NSAIDs on renal function and found no adverse effect; one study identified no adverse effect on liver function; three studies demonstrated no increase in methotrexate withdrawal; and one study showed no increase in all adverse events, including major toxic reactions. However, transient thrombocytopenia was demonstrated in one study, specifically when NSAIDs were taken on the same week day as methotrexate. This study was a retrospective review that involved small numbers only and was of moderate quality; these finding have not been replicated since.Four studies looked at specific NSAIDs (etodolac, piroxicam, celecoxib and etoricoxib), with a mean number of participants of 25.8 (range 14 to 50) and mean study duration of 16.8 (range 14 to 23) days. These studies were mainly of moderate quality. The studies were primarily pharmacokinetic studies but also reported adverse events as secondary outcomes. There were no clinically significant adverse effects with concomitant piroxicam or etodolac; and only mild adverse events with celecoxib or etoricoxib, such as nausea and vomiting, and headaches.For aspirin, seven studies provided data on adverse events with the use of aspirin and methotrexate. These studies included a mean number of participants of 100 (range 11 to 232), had a mean duration of 1325 (range 8 to 2928) days and were mainly of low to moderate quality. Two of the studies reported no evidence for increased risk of methotrexate-induced pulmonary disease and two studies showed no increase in all adverse events including major toxic reactions; however, none of these studies specified the dose of aspirin that was used. One study demonstrated that concurrent aspirin adversely affected liver function at a mean dose of 6.84 tablets of aspirin per day, which is a possible daily dose of 2.1 g presuming that 300 mg aspirin tablets were given. A further study described a partially reversible decline in renal function with 2 g daily of aspirin. One study reported no increase in adverse events with 975 g aspirin daily, however the study duration was only one week.For paracetamol, no studies were identified for inclusion.

AUTHORS' CONCLUSIONS

In the management of rheumatoid arthritis, the concurrent use of NSAIDs with methotrexate appears to be safe provided appropriate monitoring is performed. The use of anti-inflammatory doses of aspirin should be avoided.

Canadian recommendations for use of methotrexate in patients with rheumatoid arthritis

OBJECTIVE

To develop recommendations for the use of methotrexate (MTX) in patients with rheumatoid arthritis.

METHODS

Canadian rheumatologists who participated in the international 3e Initiative in Rheumatology (evidence, expertise, exchange) in 2007-2008 formulated 5 unique Canadian questions. A bibliographic team systematically reviewed the relevant literature on these 5 topics. An expert committee consisting of 26 rheumatologists from across Canada was convened, and a set of recommendations was proposed based on the results of systematic reviews combined with expert opinions using a nominal group consensus process.

RESULTS

The 5 questions addressed drug interactions, predictors of response, strategies to reduce non-serious side effects, variables to assess clinical response, and incorporating patient preference into decision-making. The systematic review retrieved 93 pertinent articles; this evidence was presented to the expert committee during the interactive workshop. After extensive discussion and voting, a total of 9 recommendations were formulated: 2 on drug interactions, 1 on predictors of response, 2 on strategies to reduce non-serious side effects, 3 on variables to assess clinical response, and 1 on incorporating patient preferences into decision-making. The level of evidence and the strength of recommendations are reported. Agreement among panelists ranged from 85% to 100%.

CONCLUSION

Nine recommendations pertaining to the use of MTX in daily practice were developed using an evidence-based approach followed by expert/physician consensus with high level of agreement.

Methotrexate drug interactions in the treatment of rheumatoid arthritis: a systematic review

OBJECTIVE

Patients with rheumatoid arthritis (RA) often have comorbidities that require multiple medications. Several of these medications may alter the efficacy or increase the toxicity of methotrexate (MTX). The purpose of our study was to determine which drugs used in combination with MTX (excluding disease modifying antirheumatic drugs, folic and folinic acid, corticosteroids, and biologic agents) enhance side effects or toxicity of MTX or lower its efficacy.

METHODS

A systematic literature search was performed with Medline, Embase, Cochrane Register and Database, and abstracts from the 2006/2007 annual congresses of the American College of Rheumatology and the European League Against Rheumatism. A manual search of the citation lists of retrieved publications was performed.

RESULTS

Of the 1172 articles identified, 67 were included: 21 pharmacokinetics studies, 5 observational studies, and 78 case reports. Most medications do not significantly affect the pharmacokinetics profile of MTX. Among the clinical studies, cytopenia and elevation of liver enzymes were the main reported toxicities. The use of trimethoprim-sulfamethoxazole (TMP-SMX) was mentioned as a risk factor for developing cytopenia in one observational study and in 17 case reports. Thirty case reports of cytopenia were attributed to the use of concomitant nonsteroidal antiinflammatory drugs, including acetylsalicylic acid. Two studies described mild abnormalities of liver enzymes with the use of isoniazid, and one study with the use of high-dose ASA.

CONCLUSION

Based on the published literature, MTX has limited drug interactions, with the exception of TMP-SMX and high-dose ASA, which can exacerbate toxicity of MTX. The clinical significance of these interactions has not been substantiated by extensive clinical observations.

Synergistic effect of iontophoresis and soluble microneedles for transdermal delivery of methotrexate

The aim of this study was to investigate the transdermal iontophoretic delivery of methotrexate, alone or in combination with microneedles, in-vitro and in-vivo using intracutaneous microdialysis in the hairless rat. The average depth of the microdialysis probe in the skin was found to be 0.54 mm. Methotrexate was stable in the presence of an applied electric field as determined by cyclic voltammetry. A current density of 0.4 mA cm−2 applied for 60 min was used in combination with maltose microneedles to enhance delivery of methotrexate across the skin. Delivery was enhanced by iontophoresis and microneedles, both in-vitro and in-vivo. A synergistic 25-fold enhancement of delivery was observed in-vivo when a combination of microneedles and iontophoresis was used compared with either modality alone.

Aberrant Phenotype and Function of Myeloid Dendritic Cells in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is characterized by a systemic autoimmune response with profound and diverse T cell changes. Dendritic cells (DCs) are important orchestrators of immune responses and have an important role in the regulation of T cell function. The objective of this study was to determine whether myeloid DCs from individuals with SLE display abnormalities in phenotype and promote abnormal T cell function. Monocyte-derived DCs and freshly isolated peripheral blood myeloid DCs from lupus patients displayed an abnormal phenotype characterized by accelerated differentiation, maturation, and secretion of proinflammatory cytokines. These abnormalities were characterized by higher expression of the DC differentiation marker CD1a, the maturation markers CD86, CD80, and HLA-DR, and the proinflammatory cytokine IL-8. In addition, SLE patients displayed selective down-regulation of the maturation marker CD83 and had abnormal responses to maturation stimuli. These abnormalities have functional relevance, as SLE DCs were able to significantly increase proliferation and activation of allogeneic T cells when compared with control DCs. We conclude that myeloid DCs from SLE patients display significant changes in phenotype which promote aberrant T cell function and could contribute to the pathogenesis of SLE and organ damage.

Lumiracoxib Does Not Affect Methotrexate Pharmacokinetics in Rheumatoid Arthritis Patients

BACKGROUND

Methotrexate and nonsteroidal antiinflammatory drugs are frequently coadministered in the treatment of rheumatoid arthritis (RA).

OBJECTIVE

To evaluate the effect of lumiracoxib, a novel cyclooxygenase-2 selective inhibitor, on methotrexate pharmacokinetics and short-term safety in patients with RA.

METHODS

This multicenter, randomized, double-blind, placebo-controlled crossover study enrolled 18 patients (mean age 49.1 y) with stable RA. Patients were randomized to receive methotrexate 7.5–15 mg orally once weekly plus either lumiracoxib 400 mg/day or placebo for 7 days. Patients then received the other treatment combination for an additional 7 days. Serial blood and urine were collected for 24 hours after the methotrexate dose on day 1 (methotrexate alone) and days 8 and 15 (combination treatment).

RESULTS

Plasma methotrexate pharmacokinetics (AUC0–t, maximum concentration [Cmax], time to Cmax) and methotrexate protein binding were similar for methotrexate alone (108.0 ng•h/mL, 26.7 ng/mL, 1.5 h, and 57.1%, respectively), methotrexate/lumiracoxib (110.2 ng•h/mL, 27.5 ng/mL, 1.0 h, and 53.7%, respectively), and methotrexate/placebo (101.8 ng•h/mL, 22.6 ng/mL, 1.0 h, and 57.0%, respectively). Similarly, no clinically significant difference was found in the urinary excretion of methotrexate. Mean exposure to the 7–OH metabolite was lower when methotrexate was given with lumiracoxib compared with placebo, shown by a reduction in AUC and Cmax, although similar amounts of the metabolite were recovered in urine following both lumiracoxib and placebo. Coadministration of methotrexate and lumiracoxib was well tolerated.

CONCLUSIONS

Lumiracoxib had no significant effect on the pharmacokinetics, protein binding, or urinary excretion of coadministered methotrexate in patients with RA.

Lack of pharmacokinetic interaction between rofecoxib and methotrexate in rheumatoid arthritis patients

Rofecoxib is a highly selective and potent inhibitor of cyclooxgenase-2 (COX-2). Methotrexate is a disease-modifying agent with a narrow therapeutic index frequently prescribed for the management of rheumatoid arthritis. The objective of this study was to investigate the influence of clinical doses of rofecoxib on the pharmacokinetics of methotrexate in patients with rheumatoid arthritis. This was a randomized, double-blind, placebo-controlled study in 25 rheumatoid arthritis patients on stable doses of methotrexate. Patients received oral methotrexate (7.5 to 20 mg) on days -1, 7, 14, and 21. Nineteen patients received rofecoxib 12.5, 25, and 50 mg once daily on days 1 to 7, 8 to 14, and 15 to 21, respectively. Six patients received placebo on days 1 to 21 only to maintain a double-blinded design for assessment of adverse experiences. Plasma and urine samples were analyzed for methotrexate and its major although inactive metabolite, 7-hydroxymethotrexate. The AUC(0-infinity) geometric mean ratios (GMR) and their 90% confidence intervals (90% CI) (rofecoxib + methotrexate/methotrexate alone) for day 7/day -1, day 14/day -1, and day 21/day -1, for rofecoxib 12.5, 25, and 50 mg, were 1.03 (0.93, 1.14), 1.02 (0.92, 1.12), and 1.06 (0.96, 1.17), respectively (p > 0.2 for all comparisons to day -1). All AUC(0-infinity), GMR and Cmax GMR 90% CIs fell within the predefined comparability limits of (0.80, 1.25). Similar results were observed for renal clearance of methotrexate and 7-hydroxymethotrexate at the highest dose of rofecoxib tested (50 mg). It was concluded that rofecoxib at doses of 12.5, 25, and 50 mg once daily has no effect on the plasma concentrations or renal clearance (tested at the highest dose of rofecoxib) of methotrexate in rheumatoid arthritis patients.

The safety profile, tolerability, and effective dose range of rofecoxib in the treatment of rheumatoid arthritis. Phase II Rofecoxib Rheumatoid Arthritis Study Group

Nonsteroidal anti-inflammatory drugs. (NSAIDs) inhibit both cyclooxygenase (COX)-1 and COX-2 isoenzymes and are effective in the treatment of inflammatory disorders. This 8-week, double-masked, placebo-controlled trial was undertaken to assess the safety profile, tolerability, and effective dose range of once-daily rofecoxib, a COX-2-specific inhibitor, in the treatment of rheumatoid arthritis (RA). After a 3- to 15-day washout of prior NSAID therapy, 658 patients were randomly allocated to receive placebo or rofecoxib 5 mg, 25 mg, or 50 mg once daily. Safety profile, tolerability, and efficacy were evaluated after 2, 4, and 8 weeks of therapy. Six hundred fifty-eight patients (168, 158, 171, and 161 in the placebo and 5-mg, 25-mg, and 50-mg rofecoxib groups, respectively) were enrolled at 79 clinical centers in the United States. Mean age was 55 years, mean duration of RA was 10 years, and 506 (77%) of the 658 patients were female. All groups had similar baseline demographic characteristics. Patients taking rofecoxib 25 and 50 mg showed significant clinical improvement compared with those taking placebo; 43.9% in the rofecoxib 25-mg group and 49.7% in the rofecoxib 50-mg group completed the treatment period and achieved an American College of Rheumatology 20 response (P = 0.025 and 0.001 vs. placebo, respectively). The 5-mg dose of rofecoxib did not differ significantly from placebo. Patients in the rofecoxib 25- and 50-mg groups showed significant improvement in key individual efficacy measurements, including patient global assessment of pain, patient and investigator global assessment of disease activity, and Stanford Health Assessment Questionnaire Disability Index (P<0.05 vs placebo). Compared with placebo, significantly fewer patients in the 25-mg and 50-mg rofecoxib groups discontinued therapy because of lack of efficacy (P = 0.02 and P = 0.032, respectively). Our results show that rofecoxib 25 and 50 mg once daily was effective and generally well-tolerated in patients with RA.