Diazoxide and labetalol in acute hypertension during haemodialysis

The antihypertensive effect of the peripheral vasodilator diazoxide in 13 patients and the alpha-beta adrenoceptor blocking agent labetalol in 12 patients were compared in 46 severe acute hypertensive episodes during haemodialysis. A single dose of diazoxide 150 mg or labetalol 50 mg was effective in 74% and 70% of the hypertensive episodes, respectively. In the diazoxide-treated patients blood pressure fell from 192 +/- 3/115 +/- 4 mmHg to 141 +/- 8/85 +/- 4 mmHg 2 h after injection. In 7 hypertensive episodes a second dose of diazoxide 150 mg was given 60 +/- 11 min after the first injection. The reduction in mean arterial blood pressure at the end of haemodialysis was 21.5 +/- 2.6% in patients treated with a single dose and 24.8 +/- 3.5% in patients treated with the repeated dose of diazoxide. In the labetalol-treated patients blood pressure in 17 instances fell from 198 +/- 5/104 +/- 4 mmHg to 143 +/- 7/89 +/- 5 mmHg 180 min following injection of labetalol 50 mg. In 6 episodes a second dose labetalol 50 mg was given 41 +/- 9 min after the first injection. At the end of haemodialysis the decrease in mean arterial blood pressure was 17.2% in patients treated with a single dose and 18 +/- 5% in patients given the repeated dose of labetalol. The reduction in blood pressure caused by diazoxide was slightly greater than that due to labetalol. At the end of haemodialysis the percentage reduction in mean arterial blood pressure was 23 +/- 2% in the diazoxide-treated group and 17 +/- 2% after labetalol.(ABSTRACT TRUNCATED AT 250 WORDS)