[Comparison of the efficacy of captopril and enalapril in single doses in the treatment of arterial hypertension. Evaluation by means of non-invasive ambulatory monitoring].

The study was designed to compare the efficacy of captopril and enalapril, both orally active inhibitors of angiotensin converting enzyme, in the treatment of primary hypertension when administered in a single daily dose. After placebo washout for two weeks, 20 hypertensive patients (I-II class, according to WHO), were admitted to active treatment, in a randomized sequence, with captopril (50 mg) and enalapril (20 mg) once a day in the morning (8 a.m.). Supine and erect blood pressure and heart rate were measured weekly, 24 hours after drug administration by using a mercury standard sphygmomanometer. In all patients ambulatory noninvasive blood pressure monitoring was performed after 4 weeks of treatment. The data confirmed the efficacy of both drugs in lowering blood pressure. However, while the antihypertensive effect of enalapril was prolonged throughout 24 hours, captopril was effective only for about 22 hours, a period longer than previously suggested on the basis of serum ACE inhibition, but not sufficient to cover the whole day. Therefore, if captopril therapy has to be used in a single daily dose an attempt should be made using an increased dosage or by employing the drug in some retarded pharmaceutical form. The need to prolong the antihypertensive effect of captopril to 24 hours is based on the clinical experience according to which the smaller the number of tablets to be taken the better the compliance. This is particularly true for cases of asymptomatic hypertension which nevertheless require lifelong therapy.