Oral labetalol given to treated non hypertensive patients with preeclampsia is no more likely to cause hypotension than magnesium sulfate

Abstract

CLAMPSIA IS NO MORE LIKELY TO CAUSE HYPOTENSION THAN MAGNESIUM SULFATE DANIELLE SMITH, JENNIFER WARREN, GEORGE SAADE, STEVEN CLARK, MICHAEL BELFORT, University of Utah, Obstetrics and Gynecology, Salt Lake City, Utah, University of Texas Medical Branch at Galveston, Obstetrics & Gynecology, Galveston, Texas, University of Utah Dept. Obstetrics and Gynecology, and HCA Healthcare Study Group, Salt Lake City, Utah OBJECTIVE: To determine whether scheduled dosing of labetalol (L) 200 mg PO given q 6 hourly to preeclamptic women causes hypotension more frequently than in those receiving MgSO4 (M). STUDY DESIGN: Hourly blood pressure profiles of preeclampic women with a BP ! 140/90 mmHg who had been randomized to receive either L or M for seizure prophylaxis during labor were examined for any episodes of hypotension as defined by a systolic (SBP) ! 90 and/or diastolic (DBP) ! 60 mmHg. Patients were studied beginning at 6 hours after admission (time of administration of the second dose of L). RESULTS: There were 115 patients in the Labetalol group and 92 in the MgSO4 group. Of these, 30 (26%) on L and 20 (22%) on M had a SBP ! 140 mmHg at the time of the second 200 mg L dose (6 hours after enrollment). One patient on L (3%), and 0 on M, subsequently had an asymptomatic SBP !90 mmHg (p = NS). In terms of DBP, 48 patients on L (42%) and 30 on M (22%) had a DBP ! 90 mmHg at the time of the second 200 mg L dose. Nine patients on L (19%), and 7 (23%) on M, subsequently had an asymptomatic DBP !60 mmHg (p = 0.77, RR 1.18 [0.62 – 2.24]). CONCLUSION: Labetalol 200 mg PO q 6 hourly, when routinely administered for seizure prophylaxis to patients with BP ! 140/90 mmHg does not cause hypotension in any greater frequency than that seen in patients on continuous MgSO4 infusion.