We did not discuss the relative merits of labetalol and sodium nitroprusside in our article,1 and thank Seamus Donaghy for pointing out the differences in duration of action between these 2 drugs.
It is true that labetalol has a longer duration of action than nitroprusside, but for the treatment of patients with acute stroke, we rely more on the fact that the onset of therapeutic effect is similar (in the range of a few minutes). Therefore, it is safe to start with a small (20 mg) intravenous bolus of labetalol, check if the desired blood pressure is achieved within 20–30 minutes and, if not, administer another bolus. In this way, it is possible to achieve a gradual reduction in blood pressure, without the risk of a too-rapid rise in blood pressure when the drug effect decreases.
Other considerations limit the use of nitroprusside: it requires continuous blood pressure monitoring (because of its short duration of action), it has toxic effects, and it is not readily available in many institutions.
Footnotes
-
Competing interests: None declared.
Reference
- 1.↵