PROSPECTIVE STUDY ON GENETIC DETERMINANTS OF CARBAMAZEPINE RESPONSE: THE CYP3A5-RS15524 GENE POLYMORPHISM IN PASHTUN PATIENTS WITH EPILEPSY
Main Article Content
Abstract
Objective: To evaluate the impact of CYP3A5-rs15524 polymorphism on the pharmacokinetics and clinical response to carbamazepine (CBZ) monotherapy in Pashtun epilepsy patients.
Materials and Methods: A longitudinal study was carried out among Pashtun patients with epilepsy in Khyber Pakhtunkhwa from October 2020 to April 2022. Participants were recruited from Lady Reading Hospital, while laboratory work was performed at the Pharmacology Department of Khyber Medical University, Peshawar. Patients were genotyped for the CYP3A5-rs15524 polymorphism using Sanger sequencing, with variants analyzed via Finch TV. The study correlated each genotype with clinical response and serum CBZ levels, which were measured using reversed-phase HPLC during each follow-up visit.
Results: A sample of 223 patients was analyzed, including 63.2% males and 36.8% females. Generalized tonic-clonic (GTC) seizures comprised 82.5% of cases, while partial seizures accounted for 17.5%. Genotype analyses showed a significant improvement in CBZ response in subsequent follow-up. At 3rd month, the non-responders / responders were recorded to be 18.3% / 31.3% for AA, 44.6% / 16.9% for AG, and 63.3% / 18.2% for GG genotype carriers. At 6th month it was recorded as 9.5% / 53% for AA, 32.3% / 32.3% for AG, and 27.3% / 54% among GG carriers, demonstrating a highly significant differences in response (p-value=0.001). Highest and lowest plasma levels across both follow-ups were observed in AA & AG genotypes, respectively with a p-value less than 0.001.
Conclusion: Our findings suggest that CYP3A5-rs15524 polymorphism may impact the pharmacokinetics and clinical response to carbamazepine in Pashtun patients with epilepsy. Clinical pharmacogenetic research has the potential to greatly enhance personalized treatment within our study population.
Article Details

This work is licensed under a Creative Commons Attribution 4.0 International License.
All articles published in the Journal of Medical Sciences (JMS) are licensed under the Creative Commons Attribution 4.0 International License (CC-BY 4.0). Under the CC BY 4.0 license, author(s) retain the ownership of the copyright publishing rights without restrictions for their content, and allow others to copy, use, print, share, modify, and distribute the content of the article even for commercial purposes as long as the original authors and the journal are properly cited. No permission is required from the author/s or the publishers for this purpose. Appropriate attribution can be provided by simply citing the original article. The corresponding author has the right to grant on behalf of all authors, a worldwide license to JMS and its licensees in all forms, formats, and media (whether known now or created in the future), The corresponding author must certify and warrant the authorship and proprietorship and should declare that he/she has not granted or assigned any of the article’s rights to any other person or body.
The corresponding author must compensate the journal for any costs, expenses, or damages that the JMS may incur as a result of any breach of these warranties including any intentional or unintentional errors, omissions, copyright issues, or plagiarism. The editorial office must be notified upon submission if an article contains materials like text, pictures, tables, or graphs from other copyrighted sources. The JMS reserves the right to remove any images, figures, tables, or other content, from any article, whether before or after publication, if concerns are raised about copyright, license, or permissions and the authors are unable to provide documentation confirming that appropriate permissions were obtained for publication of the content in question.