Endralazine, a new peripheral vasodilator--a randomized cross-over trial against dihydralazine.

In a randomized cross-over trial in 23 patients with essential hypertension, a new peripheral vasodilator, endralazine, in a dose of 10-20 mg t.i.d. was compared with dihydralazine in a dose of 25-50 mg t.i.d. All patients also received pindolol (a beta-blocker) in a dose of 5-15 mg t.i.d. The lowest dose of both drugs was given to all patients for 2 weeks and was increased only if indicated. Endralazine was more effective than dihydralazine, but the side effects were about the same in frequency and severity, apart from flushing, which was more common with endralazine. Patients receiving endralazine in the second phase of the cross-over design continued to be treated with endralazine for a period of 10-12 months. Blood pressure control remained good during this time, and the dosage was slightly reduced. No side effects suggestive of drug-induced lupus were seen, and only borderline changes in immunological tests [antinuclear antibodies (ANA)] in one patient were seen. One patient was reported to have lupus erythematosus (LE) cells in the peripheral blood but the ANA test was negative. Endralazine appears to be a useful new drug for the treatment of hypertension.