Effect of Anti-Hypertensive Drugs on Blood Pressure Lowering and Renal Function

Aim: Study aimed at evaluating blood pressure (BP) lowering effect of antihypertensive medications and their effect on renal function.

Study Design: This was a progressive observational study, evaluating the lowering effect of selected antihypertensive agents on BP and renal functions of hypertensive patients.
Study Location: The study involved moderately hypertensive patients who attended Cardiology clinic and were already receiving antihypertensive drug regimen at the University of Uyo Teaching Hospital, Uyo, Akwa-Ibom state, Nigeria. University of Uyo Teaching Hospital is a tertiary healthcare facility that was established in 1999.

Methods: Seventy hypertensive patients who received antihypertensive medications for at least 6 months were recruited for the study. The recruited participants were advised on adherence and were given adherence chart to record time of medication used. A 3 ml blood was collected and Omron digital BP meter was used to take three separate BP readings and the average was recorded. The blood samples were analysed in the laboratory for serum creatinine (Scr) by using Randox’s Scr and blood urea nitrogen (BUN) kits. The Scr was used to calculate the creatinine clearance (CrCl) by using Corkcroft-Gault equation. Participants were followed-up for three months consecutively. Statistical analysis was considered significant at p=.05. SPSS version 20 was used for the analysis.

Results: Systolic blood pressure (SBP) reduced from 130±2.64 mmHg in phase 1 to 120±1.13 mmHg in phase 3 while CrCl increased from 82.01±4.49 ml/min to 91.62±4.35 ml/min respectively. Both SBP and BUN were higher in females (131±3.30 mmHg and 2.67±0.19 µmol/l) while CrCl was higher in males (102.06±8.91 ml/min). Amlodipine (AM) reduced SBP by 9 mmHg, Lisinopril+Hydrochlorothiazide (LH) reduced SBP by 7 mmHg and Lisinopril+Amlodipine+Hydrochlorothiazide (LAH) reduced SBP by 22 mmHg. CrCl decreased among participants on AM, LH and LAH by 0.89 ml/min, 0.01 ml/min and 8 ml/min respectively.
Conclusion: Antihypertensive medications reduced SBP especially in three-drug combinations but worsened renal function.