Objective: To investigate the association of genetic variants of renin angiotensin aldosterone system, endothelial nitric oxide synthase and 11-beta-hydroxylase genes, and the drug efficacy of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker.

Methods: This two time-point study was conducted from April to November 2016 at Allied Hospital, Faisalabad and National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, and comprised of hypertensive patients taking angiotensin-converting enzyme inhibitor and angiotensin receptor blocker who were followed up for 12 weeks. Baseline and follow-up clinical and biochemical parameters were measured for all patients. Total 11 polymorphisms were genotyped by polymerase chain reaction, polymerase chain reaction-restriction fragment length polymorphism and amplification-refractory mutation system-polymerase chain reaction assays. Data was divided into baseline and follow-up groups, while the latter group was further divided into responding and nonresponding subgroups on the basis of patient response to angiotensin-converting enzyme inhibitor and angiotensin receptor blocker drugs. Data was analysed using SPSS 20. Results: Of the 45 patients, 25 (55.5%) were females and 20 (44.5%) were males. There was a significant reduction in the systolic blood pressure (p= 0.004) and low-density lipoprotein cholesterol (p< 0.001) from the baseline to the follow-up. Systolic blood pressure was significantly reduced in the responding group (p= 0.003), while diastolic blood pressure (p= 0.121) was not significantly different. There was no effect of angiotensin-converting enzyme, angiotensinogen, 11-beta-hydroxylase, aldosterone synthase and endothelial nitric oxide synthase gene polymorphisms on angiotensin converting enzyme inhibitor and angiotensin receptor blocker efficacy. Conclusion: Inter-individual response to angiotensin converting enzyme inhibitor and angiotensin receptor blocker was found to be independent of genetic polymorphisms in renin angiotensin aldosterone system, endothelial nitric oxide synthase and 11-beta-hydroxylase genes.