Tolerability of Ramipril in High Doses and Its Comparative Effects (In Combination with Hydrochlorothiazade) with Felodipine Extended Release on Mild to Moderate Hypertension in Nigerian Africans

Abstract

Angiotensin converting enzyme Inhibitors are often used in sub-optimal doses among Nigerian hypertensive patients and others at high risk of cardiovascular events because of concerns of tolerability or high cost of sustaining therapy. In an open randomized comparative trial, blood pressure lowering effects and safety of high doses of ramipril titrated over a 3 to 12 week period was compared with that of felodipine extended release (ER). Sixty patients with mild to moderate primary hypertension were randomized to receive ramipril (RP) or felodipine ER (FER) in a four phase stepped care trial of 3 weeks interval each. RP or FER was started at a dose of 5mg daily and then increased in subsequent phases according to responses. Hydrochlorothiazide (HCT) was added as required. Hematological and biochemical parameters and adverse effects were monitored.Monotherapy of FER was significantly more effective than RP in lowering blood pressure (88% FER vs. 7% RP, r= 0.020). 92% of patients treated with RP required addition of HCT (25-50mg) to achieve satisfactory blood pressure control. FER produced significantly higher mean reduction in blood pressure at the ends of weeks 3 and 6 of treatment but comparable mean changes at the end of study period. Both drugs were safe and well tolerated. Ramipril is safe at high doses of 10mg daily in black Nigerian patients with mild to moderate hypertension when titrated over an appropriate period of time and it produces comparative blood pressure lowering effects as 10mg felodipine when used in combination with 25-50mg hydrochlorothiazide.

Key words: Ramipril, high doses, felodipine ER, hypertension, blacks.