Treatment of hypertension successively with a diuretic, clonidine or a beta-blocking agent and hydralazine.

The present study was carried out in an homogenous group of 49 untreated hypertensive patients, all aged 45 years. Diastolic blood pressure was equal to or greater than 110 mmHg in successive measurements; eleven patients were classified as WHO group II, and the others as WHO group I. An initial placebo period of 3 weeks was followed by cyclothiazide medication with a good response in 6 patients. The remaining patients were given either clonidine or practolol, and by adjustment of the dose a good response was obtained in 31 patients. In these cases the treatment was exchanged after 6 weeks. The antihypertensive effect of relatively small doses of clonidine was equal to that of practolol. Since completion of the study practolol has been withdrawn because of the emergence of long term toxic effects. In 12 cases, hydralazine had to be added to obtain a satisfactory response. Mild side-effects were common, especially at the beginning of clonidine treatment, but they did not necessitate discontinuation of treatment. Further comparative studies of clonidine and beta-blockers should be carried out and more experience with the combination of clonidine and vasodilators in the treatment of hypertension is necessary.