20: Ethnic differences in anti-hypertensive medication response among pregnant and postpartum patients

Abstract

In the non-pregnant literature, it is suggested that Black patients respond better to calcium channel blockers than beta-blockers for the treatment of hypertension. In contrast, there are no ethnic specific recommendations in the treatment of acute, severe range pressures in pregnancy. The hypothesis of this study was that labetalol is less effective than nifedipine for treatment of acute, severe hypertension in pregnant and postpartum Black women relative to women of other ethnicities. This was a randomized, controlled trial of pregnant and postpartum women that presented with severe-range blood pressures. Patients were randomized to receive IV labetalol or oral nifedipine based on the American College of Obstetrics and Gynecology (ACOG) protocol for the management of acute hypertension in pregnancy. The primary outcome measured was the treatment duration needed to achieve the goal blood pressure of systolic pressure < 160 mmHg and diastolic pressure < 110 mmHg. The secondary outcomes of the study were the number of medication doses needed to achieve goal blood pressure and any maternal side effects. 109 women were randomized to labetalol or nifedipine from 9/2017 to 4/2019. Patient characteristics were similar between the two groups (Table 1). The median time to achieve goal blood pressure was 10 minutes for those who received IV labetalol and 20 minutes for those who received oral nifedipine (p< 0.0001) (Figure 1). There was no evidence of an effect of ethnicity on medication efficacy. In both groups, the median (IQR) number of medication dose was 1 (1-2), regardless of ethnicity. There was no significant difference in the side effect profile of the two medications. Our data suggests that labetalol and procardia are equally effective in the treatment of severe range BP in pregnancy, regardless of race. IV labetalol lowered severe blood pressures in pregnant and postpartum patients faster than nifedipine, though they were equally effective in terms of doses required to achieve goal blood pressure.View Large Image Figure ViewerDownload Hi-res image Download (PPT)