Daily Versus BID Nifedipine GITS in Severe Preeclampsia: Randomized Controlled Trial.

BACKGROUND Optimal dosing of nifedipine gastrointestinal therapeutic system (GITS) in pregnancies complicated by preeclampsia with severe features is unknown. We assessed whether nifedipine GITS 30 mg BID improved blood pressure control when compared with nifedipine GITS 60 mg daily. METHODS Unblinded, randomized controlled trial, at a single academic hospital from December 2021 to December 2023. Individuals between 220/7 and 335/7 weeks of gestation diagnosed with preeclampsia with severe features were randomized to nifedipine GITS 60 mg QD or 30 mg BID once the decision to increase the total daily dose was made. The primary outcome was the percentage of suboptimal blood pressures on hours 24 to 48 after randomization, defined as the ratio of systolic ≥150 mm Hg and diastolic ≥100 mm Hg blood pressure episodes divided by the total number of blood pressures taken during the collection time period. RESULTS The percentage of suboptimal blood pressure from hours 24 to 48 was similar between groups (60 mg daily: 34.2±29.4% versus 30 mg BID: 32.8±34.0%; P=0.87). The need for any emergent antihypertensive treatment during the blood pressure collection period was higher in the 60 mg daily group (46.2% versus 14.8%; P=0.03). Secondary outcomes including gestational age at delivery and number of increases in long-acting antihypertensive regimen were similar. CONCLUSIONS Nifedipine GITS dosed 60 mg daily and 30 mg BID has similar rates of suboptimal blood pressure in individuals with preeclampsia with severe features. However, there is a reduction in the need for emergent antihypertensive treatment for severe range blood pressures with BID dosing, which would favor its use in this population.