Effect of labetalol on intracranial pressure in dogs with and without intracranial hypertension.
Intracranial pressure measurements and ventricular volume pressure response curves were made during induced hypotension with labetalol, a combined alpha- and beta-adrenoceptor antagonist, in dogs without (group I) and with (group II) intracranial hypertension. The administration of 600 mg labetalol resulted in a percentage decrease of mean systemic arterial blood pressure (MAP) of 27% (+/- 10%) in group I, and 32% (+/- 9%) in group II from control values without changes in intracranial pressure and the ventricular volume pressure response curve. Larger decreases in MAP were not possible, even with a dose 3 times that clinically recommended. Labetalol may be a safe hypotensive agent to supplement neurolept analgesia, but it is not the drug of choice to induce deliberate hypotension.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002302:Cardiac Output / Q000187:drug effects; D002560:Cerebrovascular Circulation; D004285:Dogs; D004983:Ethanolamines / Q000494:pharmacology*; D005260:Female; D006973:Hypertension / Q000503:physiopathology*; D007427:Intracranial Pressure / Q000187:drug effects*; D007741:Labetalol / Q000494:pharmacology*; D008297:Male; D014655:Vascular Resistance / Q000187:drug effects
D004983:Ethanolamines; D007741:Labetalol