Effect Of Enalapril On Hepatic And Renal Function Parameters In Patients With Essential Hypertension: A Prospective, Randomised, Open-Label Study

Abstract

Background: Angiotensin-converting enzyme (ACE) inhibitors such as enalapril are first-line agents for essential hypertension, but their long-term effect on hepatic and renal function in routine clinical use is incompletely characterised. Objective: To study the effect of enalapril on hepatic (alkaline phosphatase [ALP], serum glutamic oxaloacetic transaminase [SGOT], serum glutamic pyruvic transaminase [SGPT], total bilirubin) and renal (blood urea, serum creatinine) function parameters in patients with essential hypertension. Methods: In a prospective, randomised, open-label study conducted over 12 months (1 August 2021 to 31 July 2022) in a tertiary care hospital, Ongole, newly diagnosed patients with essential hypertension aged 25–65 years with normal baseline hepatic and renal function were randomised to enalapril maleate 5 mg or telmisartan 40 mg once daily; this report presents the enalapril arm. Hepatic and renal parameters and blood pressure were recorded at baseline, 6th month and 9th month. Intragroup comparison used the paired t-test/repeated-measures ANOVA; p<0.05 was considered significant.  Results: Forty-six patients (mean age 43.56±8.37 years; 60.87% male) completed 9 months of enalapril therapy. Mean systolic and diastolic blood pressure fell from 142.60±9.41/87.93±5.82 mmHg to 117.93±8.98/75±5.86 mmHg (p<0.0001 for both). ALP rose from 79.36±19.22 to 95.28±28.04 IU/L (p<0.0001) and SGOT rose from 19.63±7.99 to 36.76±12.71 U/L (p<0.0001). SGPT (32.5±11.05 to 38.63±17.30 U/L, p=0.0533) and total bilirubin (0.68±0.23 to 0.64±0.26 mg/dL, p=0.0810) did not change significantly. Blood urea (14.86±3.80 to 14.50±3.76 mg/dL, p=0.5536) and serum creatinine (0.83±0.15 to 0.88±0.12 mg/dL, p=0.5055) remained stable. Mild adverse effects (headache, nausea, dry cough) occurred in 6/46 (13.04%) patients and resolved with continued treatment. Conclusion: Nine months of enalapril therapy produced effective blood pressure control together with a small but statistically significant rise in ALP and SGOT, without significant change in SGPT, bilirubin, or renal indices. Periodic monitoring of liver enzymes, rather than routine avoidance, appears appropriate during long-term enalapril therapy.