Real-World Effectiveness and Safety of Two-Drug Single Pill Combinations of Antihypertensive Medications for Blood Pressure Management: A Follow-Up on Daily Cardiology Practice in Douala, Cameroon

INTRODUCTION: Hypertension is the leading cause of morbidity and mortality in sub-Saharan Africa (SSA). Current guidelines recommend using two or more antihypertensive agents in single pill combinations (SPCs) to treat hypertension, but data from African patients that support these recommendations are lacking. We assessed the effectiveness and tolerance of three SPCs in lowering blood pressure (BP) amongst hypertensive patients in Douala. METHOD: All patients included in the hypertension registry of the Douala General Hospital and the Douala Cardiovascular Center between January 2010 and May 2020, and receiving a two-drug SPCs (renin-angiotensin system inhibitors (RAASi) + diuretics (DIU), calcium channel blockers (CCB) + RAASi, or DIU + CCB) were tracked from baseline through 16 weeks. Our primary outcome was a decrease in systolic BP (SBP) from baseline up to 16 weeks after initiation of treatment. A mixed linear repeated model was used to evaluate the change of SBP from baseline to week 16, while controlling for age, gender, and baseline SBP. Statistical significance was set at p < 0.05. RESULTS: Of 377 participants on two-drug SPCs, 123 were on CCB + DIU, 96 on RAASi + CCB, and 158 on RAASi + DIU. The mean age was 54.6 (± 11.2) years. At baseline, participants on RAASi + CCB presented with slightly higher SBP compared to the other two groups. Overall, the SBP decreased by 34.3 (± 14.2) mmHg from baseline values and this was comparable across the three groups of SPCs (p = 0.118). The control rate after 16 weeks of follow-up was 62.3% with no significant difference between groups. The occurrence of adverse events was 3.4% and was comparable among the three groups. CONCLUSION: The three two-drug SPCs were highly effective in reducing and controlling BP with low and similar rates of adverse effects. Long-term data documenting safety and whether these agents exert a differential cardiovascular effect in addition to and independent of their BP-lowering effect are needed for SSA populations.