Pathophysiologically based antihypertensive pharmacotherapeutics rationality, efficacy and safety in Sub Saharan African Nations - A review

Abstract

Background: Hypertension (HT) prevalence, Uncontrolled Blood Pressure (UBP), morbidity and mortality are highest in Sub-Saharan Africa (SSA). Correlating pathophysiology of HT to pharmaco-therapy with antihypertensive drugs (AHD) may bring amelioration. Aims:To review peculiarities of HT in SSA, UBP causes, diagnostic modalities, AHD use, rationality and efficacy.

Methods and results: 14 published therapeutic audits in 4 SSA nations on Google Scholar or PUBMED, (total n = 6496 patients) were evaluated. Calcium Channel blockers (CCB) amlodipine, and thiazide diuretics (TD), hydrochlorothiazide (HCTZ) were the commonest AHD. Thiazide Like Diuretics (TLD) were underutilized. The % of patients on AHD were: 1 drug 5.4-55%; 2 drugs 37-82%; >/ = 3 drugs 6-50.3%. 2-drug combinations were: ACEI/ARB + TD (42%); CCB + TD (36.8%); ACEI + CCB (15.8%) of studies. Triple/quadruple therapy included Methyldopa (MTD) with ACEI + CCB or TD. The (%) attaining BP < 140/< 90 mmHg, ranged from 29 to 53.6%, median, 44%. The co-morbidities, range and median were: Diabetes Mellitus (DM): 9.8-64%, 19.2%; Chronic Kidney Disease (CKD): 5.7-7.5%, 6.9%, and Coronary artery Disease (CAD): 0.9-2.6%, 2.3%. ACEI + CCB ± TD were the preferred AHD for comorbidities.

Conclusions: Therapeutic inertia; Non-compliance; co-morbidities; refractory HT; ignorance; substandard AHD; contribute to UBP. Studies relating 24 hour ABPM to complications and mortality in SSA hypertensives; and impact of different AHD classes on ABPM, are needed. Study of ACEI + alpha-₁ blockers + TLD on 24 hour ABPM and personalized care, are required.

Keywords: 24 hour ABPM; Antihypertensive drugs; Hypertension; Non-compliance; Resistant hypertension; Sub Saharan Africa; Therapeutic audits; Uncontrolled blood pressure.

Fig. 1

Interacting factors influencing both the efficacy and safety of antihypertensive drugs in the individual hypertensive patient, and personalized factors which should guide the choice of combination therapy of all grades of hypertension. Abbreviations: HOMA−1R Homeostatic Model Assessment, Insulin Resistance, PRA− Plasma Renin Activity, Aldo− Aldosterone, HRQoL− Health related Quality of Life, DM −Diabetes Mellitus, Met−S- Metabolic Syndrome, LVH – Left Ventricular Hypertrophy, CKD−Chronic Kidney Disease, CAD− Coronary Artery Disease, COPD− Chronic Obstructive Pulmonary Disease, RAAS – Renin Angiotensin Aldosterone System, TIA – Transient Ischemic Attacks.