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Wang WJ, Li Y, Hu YH, Wang J, Zhang YY, Fan L, Dai HR, Guo HL, Ding XS, Chen F. Population pharmacokinetics of valproic acid in children with epilepsy: Implications for dose tailoring when switching from oral syrup to sustained-release tablets. CPT Pharmacometrics Syst Pharmacol 2024. [PMID: 38923247 DOI: 10.1002/psp4.13191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 05/14/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024] Open
Abstract
Significant pharmacokinetic (PK) differences exist between different forms of valproic acid (VPA), such as syrup and sustained-release (SR) tablets. This study aimed to develop a population pharmacokinetic (PopPK) model for VPA in children with epilepsy and offer dose adjustment recommendation for switching dosage forms as needed. The study collected 1411 VPA steady-state trough concentrations (Ctrough) from 617 children with epilepsy. Using NONMEM software, a PopPK model was developed, employing a stepwise approach to identify possible variables such as demographic information and concomitant medications. The final model underwent internal and external evaluation via graphical and statistical methods. Moreover, Monte Carlo simulations were used to generate a dose tailoring strategy for typical patients weighting 20-50 kg. As a result, the PK characteristics of VPA were described using a one-compartment model with first-order absorption. The absorption rate constant (ka) was set at 2.64 and 0.46 h-1 for syrup and SR tablets. Body weight and sex were identified as significant factors affecting VPA's pharmacokinetics. The final PopPK model demonstrated acceptable prediction performance and stability during internal and external evaluation. For children taking syrup, a daily dose of 25 mg/kg resulted in the highest probability of achieving the desired target Ctrough, while a dose of 20 mg/kg/day was appropriate for those taking SR tablets. In conclusion, we established a PopPK model for VPA in children with epilepsy to tailor VPA dosage when switching between syrup and SR tablets, aiming to improve plasma VPA concentrations fluctuations.
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Affiliation(s)
- Wei-Jun Wang
- Department of Pharmacy, Pharmaceutical Sciences Research Center, Children's Hospital of Nanjing Medical University, Nanjing, China
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Yue Li
- Department of Pharmacy, Pharmaceutical Sciences Research Center, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Ya-Hui Hu
- Department of Pharmacy, Pharmaceutical Sciences Research Center, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Jie Wang
- Department of Pharmacy, Pharmaceutical Sciences Research Center, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Yuan-Yuan Zhang
- Department of Pharmacy, Pharmaceutical Sciences Research Center, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Lin Fan
- Department of Pharmacy, Pharmaceutical Sciences Research Center, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Hao-Ran Dai
- Department of Pharmacy, Pharmaceutical Sciences Research Center, Children's Hospital of Nanjing Medical University, Nanjing, China
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Hong-Li Guo
- Department of Pharmacy, Pharmaceutical Sciences Research Center, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Xuan-Sheng Ding
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Feng Chen
- Department of Pharmacy, Pharmaceutical Sciences Research Center, Children's Hospital of Nanjing Medical University, Nanjing, China
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Sh Dashyan S, Babaev EV, Ayvazyan AG, Mamyan SS, Paronikyan EG, Nikoghosyan TA, Hunanyan LS, Paronikyan RG. Synthesis, evaluation of biological activity and SAR of new thioalkyl derivatives of pyridine. Bioorg Chem 2024; 148:107435. [PMID: 38762999 DOI: 10.1016/j.bioorg.2024.107435] [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: 03/16/2024] [Revised: 05/06/2024] [Accepted: 05/07/2024] [Indexed: 05/21/2024]
Abstract
BACKGROUND Pyridine and its derivatives play a vital role in medicinal chemistry, serving as key scaffolds for drugs. The ability to bind to biological targets makes pyridine compounds significant, sparking interest in creating new pyridine-based drugs. Thus, the purpose of the research is to synthesize new thioalkyl derivatives of pyridine, predict their biological spectrum, study their psychotropic properties, and based on these findings, perform structure-activity relationships to assess pharmacophore functional groups. METHODS Classical organic methods were employed for synthesizing new thioalkyl derivatives of pyridine, with a multifaceted pharmacological profiles. Various software packages and methods were employed to evaluate the biological spectrum of the newly synthesized compounds. For the evaluation of neurotropic activity of new synthesized compounds, some biological methods were used according to indicators characterizing anticonvulsant, sedative and antianxiety activity as well as side effects. RESULTS Effective synthetic methods for 6-amino-4-phenyl-2-thio-2H-thiopyran-5-carboxylic acid ethyl ester, 2-amino substituted thiopyridine derivatives and 6-cycloamino-2-thioalkyl-4-phenylnicotinate derivatives were obtained in high yield. Predicted biological spectra and pharmacokinetic data indicated high gastrointestinal absorption and low blood-brain barrier passage for most compounds and demonstrated potential various biological effects, particularly psychotropic properties. Studied compounds demonstrated high anticonvulsant activity through antagonism with pentylenetetrazole. They exhibited low toxicity without inducing muscle relaxation in the studied doses. In psychotropic studies, the compounds displayed activating, sedative, and anxiolytic effects. Notably, the 6-amino-2-thioalkyl-4-phenylnicotinate derivatives demonstrated significant anxiolytic activity (about four times more compared to diazepam). They also exhibited pronounced sedative effects. Ethyl 2-({2-[(diphenylmethyl)amino]-2-oxoethyl}thio)-4-phenyl-6-pyrrolidin-1-ylnicotinate exhibited anxiolytic activity even two times greater than diazepam. Moreover, all studied compounds showed statistically significant antidepressant effects. Noteworthy ethyl 2-({2-oxo-2-[(tetrahydrofuran-2-ylmethyl)amino]ethyl}thio)-4-phenyl-6-pyrrolidin-1-ylnicotinate showcasing its unique psychotropic effect. CONCLUSIONS The selected compounds demonstrate anticonvulsant properties, activating behavior, and anxiolytic effects, while simultaneously exhibiting antidepressant effects and these compounds as promising candidates for further exploration in the development of therapeutics with a broad spectrum of neuropsychiatric applications.
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Affiliation(s)
- Shushanik Sh Dashyan
- Scientific Technological Center of Organic and Pharmaceutical Chemistry of National Academy of Sciences of Republic of Armenia, Ave. Azatutyan 26, Yerevan 0014, Armenia; Eurasia International University of Republic of Armenia, Pharmacy faculty, Ave. Azatutyan 24/2, Yerevan 0014, Armenia.
| | - Eugene V Babaev
- Faculty of Chemistry, Moscow State University, 1, GSP-1, 1-3 Leninskiye Gory, 119991 Moscow, Russia
| | - Armen G Ayvazyan
- Scientific Technological Center of Organic and Pharmaceutical Chemistry of National Academy of Sciences of Republic of Armenia, Ave. Azatutyan 26, Yerevan 0014, Armenia
| | - Suren S Mamyan
- Scientific Technological Center of Organic and Pharmaceutical Chemistry of National Academy of Sciences of Republic of Armenia, Ave. Azatutyan 26, Yerevan 0014, Armenia
| | - Ervand G Paronikyan
- Scientific Technological Center of Organic and Pharmaceutical Chemistry of National Academy of Sciences of Republic of Armenia, Ave. Azatutyan 26, Yerevan 0014, Armenia
| | - Tigranuhi A Nikoghosyan
- Scientific Technological Center of Organic and Pharmaceutical Chemistry of National Academy of Sciences of Republic of Armenia, Ave. Azatutyan 26, Yerevan 0014, Armenia
| | - Lernik S Hunanyan
- Scientific Technological Center of Organic and Pharmaceutical Chemistry of National Academy of Sciences of Republic of Armenia, Ave. Azatutyan 26, Yerevan 0014, Armenia
| | - Ruzanna G Paronikyan
- Scientific Technological Center of Organic and Pharmaceutical Chemistry of National Academy of Sciences of Republic of Armenia, Ave. Azatutyan 26, Yerevan 0014, Armenia
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Zhang CQ, Li HY, Wan Y, Bai XY, Gan L, Wang J, Sun HB. Efficacy, Safety, and Retention Rate of Extended-Release Divalproex Versus Conventional Delayed-Release Divalproex: A Meta-Analysis of Controlled Clinical Trials. Front Pharmacol 2022; 13:811017. [PMID: 35479307 PMCID: PMC9037144 DOI: 10.3389/fphar.2022.811017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/23/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose: A novel once-daily divalproex-extended release (ER) dose formulation has been developed; this formulation prolongs the therapeutic serum levels of the drug, compared with the twice-daily conventional divalproex-delayed release (DR) formulation. This study aimed to systematically examine and compare the efficacy, safety, and retention rates of the ER divalproex (VPA-ER) and conventional DR divalproex (VPA-DR) formulations. Methods: Randomized control trials (RCTs) reporting the efficacy, adverse events (AEs), and medication compliance of ER and DR divalproex were searched in online databases, including PubMed, Embase, and Cochrane Library databases, by searching MeSH words and term words. Observational studies with potential biases were excluded. The meta-analysis was performed using Stata 16.0 software. Findings: Thirteen RCTs, involving 1,028 participants, were included in this meta-analysis. Efficacy, AEs, and drug retention rates were the main study outcomes. According to our study, VPA-ER presented clinically significant benefits compared with the placebo in the population with bipolar disorder (BD) (39.5% versus 27.2%, p < 0.001). A similar efficacy of VPA-ER and VPA-DR in controlling seizures was observed in epilepsy patients (87.4% versus 86.5%, p = 0.769). A significantly lower incidence of AEs was reported in the VPA-ER group than in the placebo group (26.8% versus 34.8%, p = 0.003). By contrast, there was no evidence of difference in safety between VPA-ER and VPA-DR (29.4% versus 30.5%, p = 0.750). In addition, the drug retention rate was significantly lower in the VPA-ER group than in the placebo group (76.0% versus 82.7%, p = 0.020), especially in migraine patients (p = 0.022) and in patients who were treated for fewer than 4 weeks (p = 0.018). Implications: The efficacy of VPA-ER was significantly superior to that of the placebo treatment, which provided efficacy similar to that of conventional VPA-DR. VPA-ER is well tolerated with a low rate of AEs compared to the placebo. In addition, the acceptable medicine compliance of VPA-ER was conducive to the long-term maintenance treatment of chronic diseases. Although we analyzed open labels and crossover design RCTs, large-scale multicenter studies on the efficacy and medicine compliance of new ER formulations with less AEs are required to validate our conclusion.
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Affiliation(s)
- Chen Qi Zhang
- Department of Special-Need Medical, Chengdu BOE Hospital, Chengdu, China
| | - Hong Yan Li
- Department of Special-Need Medical, Chengdu BOE Hospital, Chengdu, China
| | - Yong Wan
- Department of Special-Need Medical, Chengdu BOE Hospital, Chengdu, China
| | - Xue Yang Bai
- Department of Special-Need Medical, Chengdu BOE Hospital, Chengdu, China
| | - Lu Gan
- Department of Special-Need Medical, Chengdu BOE Hospital, Chengdu, China
| | - Juan Wang
- Department of Special-Need Medical, Chengdu BOE Hospital, Chengdu, China
| | - Hong Bin Sun
- Department of Neurology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
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Zhang CQ, Bai XY, Wan Y, Li HY, Sun H. Efficacy, safety, and retention rate of extended-release divalproex versus conventional delayed-release divalproex: A protocol for systematic review and meta-analysis. Medicine (Baltimore) 2021; 100:e28290. [PMID: 34918705 PMCID: PMC8678006 DOI: 10.1097/md.0000000000028290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 11/29/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND A novel once-daily divalproex-extended release (VPA-ER) dose formulation has been developed, which prolongs therapeutic serum levels compared with that of twice-daily conventional divalproex-delayed release (VPA-DR). Currently, there is lack of meta-analysis focusing on drug retention rate between VPA-ER and VPA-DR. Thus, our study is the first one that aims to systematically examine and compare the efficacy, safety, and retention rate of VPA-ER and VPA-DR. METHODS Online databases including MEDLINE via PubMed, Cochrane Library, Embase (up to October 30, 2021) will be applied for literature screen. We will conduct meta-analysis by using Stata16.0 software. RESULTS This study aims to evaluate the efficacy, safety, and drug retention rate of VPA-ER versus conventional VPA-DR. CONCLUSION Once-daily VPA-ER may present a positive efficacy and not increase the incidence of AEs and has a higher retention rate for patients, which can be used as a substitute for conventional VPA-DR.INPLASY registration number: INPLASY2021110090(DOI: 10.37766/inplasy2021.11.0090).
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Affiliation(s)
- Chen Qi Zhang
- Department of Special Medical, Chengdu BOE Hospital, Chengdu, Sichuan Province, China
| | - Xue Yang Bai
- Department of Special Medical, Chengdu BOE Hospital, Chengdu, Sichuan Province, China
| | - Yong Wan
- Department of Special Medical, Chengdu BOE Hospital, Chengdu, Sichuan Province, China
| | - Hong Yan Li
- Department of Special Medical, Chengdu BOE Hospital, Chengdu, Sichuan Province, China
| | - Hongbin Sun
- Department of Neurology, The Air Force Hospital of Western Theater Command, Chengdu, Sichuan Province, China
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Jost J, Preux PM, Druet-Cabanac M, Ratsimbazafy V. How to reduce the treatment gap for people with epilepsy in resource-limited settings by innovative galenic formulations: A review of the current situation, overview of potential techniques, interests and limits. Epilepsy Res 2016; 119:49-61. [DOI: 10.1016/j.eplepsyres.2015.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 08/24/2015] [Accepted: 10/25/2015] [Indexed: 10/22/2022]
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Verrotti A, Nanni G, Agostinelli S, Alleva ET, Aloisi P, Franzoni E, Spalice A, Chiarelli F, Coppola G. Effects of the abrupt switch from solution to modified-release granule formulation of valproate. Acta Neurol Scand 2012; 125:e14-8. [PMID: 21707552 DOI: 10.1111/j.1600-0404.2011.01568.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND A new modified-release (MR) granule formulation of valproate (VPA) has been recently developed for the treatment of children with epilepsy. It consists of tasteless microspheres that can be sprinkled on soft foods and easily swallowed. There are no data on the effectiveness of this formulation in pediatric age. AIM OF THE STUDY To evaluate the effects of the abrupt switch from solution to VPA MR granules in children undergoing chronic treatment. METHODS We enrolled children receiving VPA solution as sole or adjunctive therapy and switched them to MR granules at identical dosages. VPA blood level, treatment efficacy (clinical and EEG data), tolerability (adverse reactions), palatability, ease of administration, and compliance were evaluated before switching (T0) and after 4 weeks (T1). RESULTS Out of 112 enrolled children, 108 (96.4%) completed the evaluation. We observed no significant differences between the patients at T0 and T1 in VPA blood levels, treatment efficacy, tolerability, and compliance. MR granules were judged more palatable (P < 0.05) and easier to administer (P < 0.05) than solution by children and parents. At 6-month follow-up, all patients continued to use MR granules. CONCLUSION Modified-release granule formulation of VPA may be a reliable alternative to solution for its convenience of use.
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Affiliation(s)
- A Verrotti
- Department of Pediatrics, University of Chieti, Italy
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Dedeurwaerdere S, van Raay L, Morris M, Reed R, Hogan R, O’Brien T. Fluctuating and constant valproate administration gives equivalent seizure control in rats with genetic and acquired epilepsy. Seizure 2011; 20:72-9. [DOI: 10.1016/j.seizure.2010.10.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 10/04/2010] [Accepted: 10/15/2010] [Indexed: 11/28/2022] Open
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Zaid AN. Attitude and perception of patients and health care practitioners toward oral sustained release dosage forms in Palestine. Saudi Pharm J 2010; 18:251-6. [PMID: 23960735 DOI: 10.1016/j.jsps.2010.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 07/04/2010] [Indexed: 10/18/2022] Open
Abstract
AIM To evaluate the knowledge of health professionals in Palestine regarding the advantages of sustained release dosage forms (SRDFs) over conventional therapy. METHODS Data were gathered from a questionnaire that was handed out to community pharmacists, physicians and patients. Pharmaceutical industry decision makers were enrolled in this study. Data were analyzed using the SPSS. RESULTS Pharmacists (92.9%) and 89.2% of physicians thought that SRDFs improve patient compliance. 81.5% of pharmacists and 77% of physicians were in agreement regarding the capacity of SRDFs to maintain therapeutic activity during night. In this study, 81.5% of pharmacists and 81% of physicians believed that SRDFs provide further advantage with psychiatric patients who forget to take their medications. Pharmacists (63.1%) and only 63.5% of physicians believed that SRDFs yield a time saving for nurses who use SRDFs in hospital. Only 45.3% of physicians and 43.4% of pharmacists thought that SRDFs result in cost saving due to better disease management. Pharmacists (95.2%) and 95.9% of physicians agreed that SRDFs could be the right choice for faith patient's who must take their medication during the month of Ramadan. Pharmacists (66.7%) and 50.7% of physicians recognize that SRDFs may be unsafe if they are improperly formulated. Bad swallowing was also recognized as inconveniences of SRDFs by 67.9% of pharmacists and 57.3% of physicians. Given the above advantages, 75% of patients showed economical problems regarding the cost of the single course therapy of SRDFs and 100% of interviewed patients were enthusiastic about the advantage of SRDFs during Ramadan. CONCLUSION The advantages of SRDFs are not completely understood by Palestinian health professionals. Pharmaceutical industries should pay more attention to the development and advertising of SRDFs due to the valuable advantages of these dosage forms.
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Affiliation(s)
- Abdel Naser Zaid
- Pharmaceutical Chemistry and Technology, College of Pharmacy, An-Najah National University, Nablus, Palestine
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Reed RC, Meinhold J, Dutta S, Liu W, Qiu Y. What do the suffixes - XR, ER, Chrono, Chronosphere - really mean as it pertains to modified-release antiepileptic drugs? J Clin Pharm Ther 2010; 35:373-83. [DOI: 10.1111/j.1365-2710.2009.01117.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Senn SM, Kantor S, Poulton IJ, Morris MJ, Sims NA, O'Brien TJ, Wark JD. Adverse effects of valproate on bone: defining a model to investigate the pathophysiology. Epilepsia 2010; 51:984-93. [PMID: 20163440 DOI: 10.1111/j.1528-1167.2009.02516.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Bone disease and fractures are common with chronic antiepileptic drug (AED) therapy, but the underlying mechanisms are poorly understood. This study aimed to characterize adverse bone effects of valproate and to identify mouse strains either resistant or sensitive to these effects. METHODS Seven mouse strains (n = 40/strain; 10/diet) were screened for the effect of chronic (8 weeks) valproate treatment (0, 2, 4, and 6 g/kg food) on total bone mineral content (BMC, by dual energy x-ray absorptiometry). In a confirmatory study the effect of valproate (0 or 4 g/kg food) over 16 weeks was assessed in five of the mouse strains (n = 60/strain; 30/diet) identified in the screening phase as either sensitive or resistant. Ex vivo volumetric bone measures and structural changes were assessed using peripheral quantitative computed tomography (pQCT) and histomorphometry. RESULTS Chronic valproate treatment reproducibly affected bone in C3H/HeJ mice, with a 9.1% (p < 0.01) reduction in total BMC and a 10.7% (p < 0.01) reduction in trabecular volumetric density, indicating a sensitive strain to AED-induced bone loss. Histomorphometry was consistent, revealing reductions in trabecular volume (19.6%, p < 0.05) and number (14.3%, p < 0.04), and a 19.9% (p < 0.05) increase in trabecular separation. In contrast the A/J mice were reproducibly resistant to the bone effects. CONCLUSION Mouse strains sensitive and resistant to the adverse bone effects of chronic valproate treatment were identified. The strain-specific effects suggest a role of genetic factors in the pathogenesis of AED-induced bone disease. This novel model provides a new, powerful tool to investigate the pathophysiology and therapy of AED-associated bone disease.
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Affiliation(s)
- Susan M Senn
- Department of Medicine, Bone Mineral Service and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Melbourne, Victoria, Australia
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Once-daily dosing is appropriate for extended-release divalproex over a wide dose range, but not for enteric-coated, delayed-release divalproex: evidence via computer simulations and implications for epilepsy therapy. Epilepsy Res 2009; 87:260-7. [PMID: 19892524 DOI: 10.1016/j.eplepsyres.2009.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Revised: 09/02/2009] [Accepted: 09/20/2009] [Indexed: 11/22/2022]
Abstract
Divalproex sodium extended-release (divalproex-ER), administered once-daily, maintains plasma valproic acid (VPA) concentrations for 24h, whereas enteric-coated, delayed-release divalproex sodium (divalproex) requires multiple-daily doses to do the same. We hypothesize that a once-daily divalproex regimen should not be administered to epilepsy patients requiring high total daily doses, e.g., 35.6-56 mg/kg/day, due to the potential for high (>125 mg/L) maximum VPA concentrations (C(max)). We examined the impact of once-daily dosing, divalproex vs. divalproex-ER, on steady-state plasma VPA concentration-time profiles at commonly used doses in monotherapy (uninduced) and polytherapy (hepatic enzyme-induced) virtual adult patients. Only the 1125 mg once-daily divalproex dose had mean C(max)<100mg/L; >or=2000 mg produced mean C(max)>or=125 mg/L. Mean divalproex C(min) was approximately 50 mg/L at two of four doses tested, whereas mean ER C(min) was >73 mg/L at all doses tested. Once-daily divalproex peak-trough fluctuation was 4.4-6.2-fold greater than once-daily divalproex-ER. We predict that excursions beyond the conventional recommended VPA plasma concentration range will commonly occur with high total mg daily doses (>or=2000 mg) of enteric-coated divalproex, if dosed once-daily, potentially producing clinical toxicity. This divalproex formulation should not be dosed once-daily at high total mg daily doses due to this risk. Divalproex-ER is the appropriate formulation for administration on a once-daily basis, especially if large total mg/day doses are required for the control of seizure activity.
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Affiliation(s)
- Stephen Lowis
- Department of Paediatric and Adolescent Oncology, Bristol Royal Hospital for Children, Bristol, UK.
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Fujii A, Yasui-Furukori N, Nakagami T, Niioka T, Saito M, Sato Y, Kaneko S. Comparative in vivo bioequivalence and in vitro dissolution of two valproic acid sustained-release formulations. DRUG DESIGN DEVELOPMENT AND THERAPY 2009; 2:139-44. [PMID: 19920901 PMCID: PMC2761171 DOI: 10.2147/dddt.s3556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Objective A study was conducted to establish the bioequivalence between different sustained-release formulations of valproic acid (Depakene R and Selenica R), which were developed in Japan. Materials and methods The clinical investigation was designed in a randomized, crossover fashion with a single dose given to 12 healthy subjects. The subjects were administered a single 600 mg dose of valproic acid in one of two formulations. Serial venous blood samples were obtained over 72 hours after each administration to measure valproic acid in serum by enzyme immunoassay (EIA). In addition, a dissolution test was performed. Each sample was analyzed by an high-performance liquid chromatography to determine the dissolution rate of valproic acid. Results No difference in maximum concentration or area under the curve was found between the two formulations. The time to maximum concentration of the new formation was significantly delayed compared with the conventional formulation (10.8 ± 1.7 versus 17.6 ± 1.8 hours, p < 0.001). Apparent clearance or elimination half-life did not differ between the two formulations. An in vitro dissolution study showed that Depakene R was significantly more dissoluble than Selenica R. Conclusion Based on the results, the present study demonstrated a significant difference between the two sustained-release formulations in the absorption profile, and also demonstrated that the bioavailability of valproic acid in the two formulations was similar but absorption speed (lag time) was very different.
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Affiliation(s)
- Akira Fujii
- Department of Neuropsychiatry, Hirosaki University School of Medicine, Hirosaki, Japan
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Yasui-Furukori N, Saito M, Nakagami T, Niioka T, Sato Y, Fujii A, Kaneko S. Different serum concentrations of steady-state valproic acid in two sustained-release formulations. Psychiatry Clin Neurosci 2007; 61:308-12. [PMID: 17472600 DOI: 10.1111/j.1440-1819.2007.01656.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recently a new sustained-release formulation of valproic acid has been developed in Japan. The sustained-release mechanism of the new formulation was different from the conventional formulation. The aim of the present study was to compare the pharmacokinetic characteristics of valproic acid in two sustained-release formulations. Different sustained-release formulations of valproic acid (Depakene R and Selenica R) were administered in a randomized cross-over fashion in repeated doses in 24 psychiatric patients. After > or = 4 weeks administration of valproic acid once daily, blood samples were taken just before (0 h) and 8, 12, 24 h after the morning dose. Blood sampling was performed in the same manner in the same patients 4 weeks after switching from one to the other formulation of valproic acid. Serum concentrations of valproic acid at 0 h (50.7 +/- 19.4 vs 44.9 +/- 21.8 microg/mL, P < 0.05) and 24 h (52.3 +/- 19.54 vs 6.2 +/- 22.2 microg/mL, P < 0.05) were significantly higher during Selenica R than during Depakene R treatment, whereas the serum concentration of valproic acid at 8 h (49.7 +/- 19.2 vs 62.4 +/- 25.6 microg/mL, P < 0.01) was significantly lower during Selenica R treatment than during Depakene R treatment. Serum concentrations of valproic acid at 12 h were not different. The present study demonstrated that steady-state serum concentrations were different because of the different dissolution profiles. When a prescription for valproic acid is switched from one drug to the other, prescribers should be aware that the therapeutic drug monitoring data are not consistent.
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Affiliation(s)
- Norio Yasui-Furukori
- Department of Neuropsychiatry, Hirosaki University School of Medicine, Hirosaki, Japan.
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