Labetalol as a hypotensive agent in otological operations.

The usefulness of labetalol, a new combined alpha and beta adrenoceptor antagonist as a hypotensive agent in otological operations was studied in 18 otherwise healthy patients. After a single 1.0 mg/kg i.v. dose the maximum decrease in systolic (18%) and diastolic (8%) blood pressure occured between 5 to 15 minutes (mean 11 min), and the pretreatment blood pressure values were reached in 15 to 55 min (mean 26 min). Similarly, after a single 2.0 mg/kg i.v. dose the maximum blood pressure decrease (32%/20%) was observed in 5 to 40 minutes (mean 23.5 min) lasting 30 to 95 minutes (mean 60.1 min). Generally, a moderate decrease in blood pressure without a concomitant increase in heart rate or excessive hypotension was found.