Enalapril and hydrochlorothiazide in hypertensive Africans

Abstract

The antihypertensive efficacy both of angiotensin converting enzyme (ACE) inhibitors and thiazide diuretics has been claimed to be influenced by plasma renin activity, which declines with age and is low in blacks. In a double-blind, placebo-controlled, double-dummy, randomized, parallel-group preliminary study, the antihypertensive efficacy and tolerability of the ACE inhibitor enalapril (20 mg day-1) and hydrochlorothiazide (50 mg day-1) were evaluated and compared for 4 weeks in 20 African patients with essential hypertension. The two groups had similar baseline clinical features and serum Na+ and K+ levels. Hydrochlorothiazide caused a significant and sustained fall in erect blood pressure with a reflex tachycardia. Enalapril exerted only a modest antihypertensive action, but significantly reduced erect heart rate. Direct comparison of hydrochlorothiazide- and enalapril-induced hypotension suggested a greater fall in subjects on the thiazide. The 95% confidence limits for the thiazide-enalapril difference in antihypertensive action at the end of the study was 39.5 to -7.5 mm Hg systolic and 22.0 to -6.6 mm Hg diastolic. The maximal blood pressure fall after hydrochlorothiazide was positively correlated with age (r = 0.50; p less than 0.05), whilst that of enalapril was inversely related age to (r = -0.57, p less than 0.05). The results are compatible with the notion that ACE inhibitor monotherapy may be less effective than thiazide diuretic treatment in African and black patients with essential hypertension. The findings also support the concept that age and racial factors may influence the response to antihypertensive treatment.

Blood pressure profile in Nigerian children

“…Our findings, therefore, are consistent with a number of other reports (13,14) which indicate that at best body dimension only exerts a minor difference in BP in some paediatric population. Of note, the literature suggests that over-weight is not a common concomitant of elevated BP in adult Nigerians (15)(16)(17). Therefore, our findings reinforce the position (13,14) that in some populations, the influence of body size on BP in relation to other factors, such as age and heredity may have been overstated.…”

Shifting trends in the pharmacologic treatment of hypertension in a Nigerian tertiary hospital: a real-world evaluation of the efficacy, safety, rationality and pharmaco-economics of old and newer antihypertensive drugs

“…12 Since our therapeutic audit in 1989, 12 novel antihypertensive drugs such as calcium antagonists 13,14 and angiotensin-converting enzyme inhibitors (ACEIs) 14,15 have been introduced into routine clinical practice in Nigeria. In our earlier study, 12 we highlighted the much more dismal prognosis of patients with concurrent hypertension with diabetes, which has been confirmed in a more recent study.…”

Observations on the Use of Low-Dose Hydrochlorothiazide in the Treatment of Hypertension in Diabetic Nigerians

“…Earlier studies [8,10,17] in Nigeria showed that daily doses of hydrochlorothiazide (HCTZ) as high as 50 mg alone or 100 mg in combination with amiloride (Moduretic ® ) or K + supplementation effectively lower BP without metabolic side effects, e.g. hypokalaemia or glucose intolerance.…”

“…Part of the problem may be linked to the routine use of newer antihypertensive drugs such as · 1 -adrenergic blockers and angiotensin-converting enzyme (ACE) inhibitors, which are held to be more desirable for the treatment of hypertension in diabetes; however, these categories of medications are relatively ineffective in Nigerians and other black Africans [8][9][10][11][12] and are also far more expensive than thiazides. In contrast, thiazides are relatively more effective in black Africans and are also widely available and cheap [5][6][7][8][9][10][11], but are hardly prescribed for diabetics with hypertension, probably for fear of inducing hypokalaemia and aggravating the control of existing diabetes [13][14][15][16].…”