Antihypertensive activity of a new vasodilator, cadralazine, administered alone or in combination with a beta-blocker.

The antihypertensive activity of a new arterial dilator, cadralazine, was evaluated in 40 patients with mild-to-moderate arterial hypertension. Cadralazine was given once daily over 6 weeks, and blood pressure and heart rate were recorded 24-26 hours after dosing. Cadralazine dose was 10 mg daily initially, and 15 or 20 mg daily from the 3rd or 5th trial week according to a target diastolic pressure reduction to 95 mmHg or below. Slow-release metoprolol 200 mg once daily was added when heart rate increase exceeded 25% of the pretreatment value. Blood pressure showed a significant and progressive reduction throughout the study period, both in the patients receiving cadralazine as monotherapy (19 patients) and in those who added metoprolol (21 patients). The target diastolic pressure reduction was reached in 2 patients with the 10-mg dose, in 19 of the remaining 38 patients with the 15-mg dose, and in 13 of the other 19 patients with the 20-mg dose. Considering only those patients who did not add metoprolol, the target was reached in the 2 patients with the 10-mg dose, in 10 of the 19 patients with the 15-mg dose and in 7 of the 19 patients with the 20-mg dose. None of the laboratory tests showed clinically relevant changes. Neither LE cells nor antinuclear antibodies were found. In conclusion, cadralazine is a promising long-acting antihypertensive vasodilator. A clinically satisfactory antihypertensive effect is achieved mostly by a 15-mg or a 20-mg dose given once daily.(ABSTRACT TRUNCATED AT 250 WORDS)