The use of felodipine in the treatment of severe hypertension.

To investigate the use of felodipine in severe hypertension 2 separate studies were carried out. In the first study, 101 patients on a fixed combination of atenolol 100mg and chlorthalidone 25mg who required additional or 'third line' therapy for proper control, were randomised to either felodipine or hydralazine and the dosage was increased if the supine diastolic blood pressure was greater than 90mm Hg. Felodipine reduced blood pressure more effectively than hydralazine and the incidence of adverse reactions was similar in both groups. In the second study, 17 patients with severe hypertension (WHO stage III), who had not been controlled by therapy with atenolol, thiazide diuretic and hydralazine, prazosin or nifedipine were studied. Patients were subsequently controlled by a combination of atenolol, frusemide or bumetanide, and minoxidil. Once stabilised, the patients then took part in a double-blind crossover study comparing minoxidil and felodipine. The patients' blood pressure was the same on both treatment regimes but their bodyweight was lower after felodipine administration. Felodipine is probably more effective than hydralazine and as effective as minoxidil in treating severe hypertension. As felodipine is usually well tolerated it should prove a useful drug in treating refractory hypertension.