Once-Daily Nifedipine Sufficient for Pregnancy Hypertension

BALTIMORE — A single 30-mg daily dose of nifedipine appeared similarly effective as 60 mg taken in two daily doses for treating hypertensive disorders in pregnancy, according to research presented at the annual clinical and scientific meeting of the American College of Obstetricians and Gynecologists.

The findings suggest that starting patients on a once-daily 30-mg dose is therefore reasonable, Isabelle Band, BA, a medical student at the Icahn School of Medicine at Mount Sinai, New York, told attendees. Band said in an interview that there does not appear to be a consensus on the standard of care for nifedipine dosing in this population but that previous in vitro studies have shown a faster metabolism of nifedipine in a physiologic state that mimics pregnancy.

“I’ve spoken to some colleagues here who say that they frequently have this debate of which dosing regimen to go with,” Band said. “I was pleasantly surprised that there was no significant difference between the two dosing regimens because once-daily dosing is less burdensome for patients and will likely improve compliance and convenience for patients.” An additional benefit of once-daily dosing relates to payers because anecdotal reports suggest insurance companies do not tend to approve twice-daily dosing as readily as once-daily dosing, Band added.

Band and her colleagues conducted a retrospective chart review of all patients with hypertensive disorders of pregnancy who were admitted to the Mount Sinai Health System between Jan. 1, 2015, and April 30, 2021, and were prescribed nifedipine in a once-daily (30 mg) or twice-daily (60 mg) dose. They excluded patients with renal disease and those already taking hypertensives prior to admission.

Among 237 patients who met the criteria, 59% received 30 mg in a once-daily dose, and 41% received 60 mg in twice-daily doses. Among patients requiring an up titration, two-thirds (67%) needed an increase in the nifedipine dose — the most common adjustment — and 20.7% needed both an increase in nifedipine and an additional medication.

No significant difference existed between the proportion of patients needing a dose increase or an additional oral hypertensive agent between those taking the once-daily 30-mg dose (33.8%) and those taking the twice-daily 60-mg dose (35.7%). This finding remained statistically insignificant after controlling for gestational diabetes, delivery mode, administration of Lasix, and receipt of emergency antihypertensive treatment (P = .71). The time that passed before patients needed a dose increase was also statistically similar between the groups: 24.3 hours in the 30-mg group and 24 hours in the 60-mg group (P = .49).

There were no statistically significant differences in the need for a dose increase or an additional hypertensive agent based on race, ethnicity, body mass index, or history of preeclampsia as well. However, 24.5% of those taking the 60-mg dose had a history of preeclampsia, compared to 7.2% of those taking the 30 mg dose (P < .001). Further, the median number of prior pregnancies was two in the 30-mg group versus three in the 60-mg group (P = .002).

The authors found no significant difference between the two dosing groups in the need for emergency hypertensive treatment after reaching the study dose or in readmission for blood pressure control. In the 30-mg group, 21.6% of patients needed emergency antihypertensive treatment, compared with 14.3% in the 60-mg group (P = .19). Readmission was necessary for 7.2% of the 30-mg group and 6.1% of the 60-mg group (P > .99).

A subgroup analysis compared those who started nifedipine antepartum and those who started it postpartum, but again, no significant difference in the dosing regimens existed.

Michael Ruma, MD, a maternal-fetal medicine specialist at Perinatal Associates of New Mexico in Albuquerque, was not involved in the study and said he welcomed the results.

“We have too many choices in medicine, so we need to just simplify the plan of attack,” reducing the number of things that clinicians need to think about, Ruma said in an interview. “A singular dose is always easiest for the patient, always easier for nursing staff, and usually, if you can optimize the dosing, that’s the best approach.”

Annabeth Brewton, MD, a resident at University of Tennessee, Knoxville, agreed, adding that new parents already have a lot going on immediately postpartum.

“They’re going to be breastfeeding, they’re not sleeping, they’re going to forget to take that [second] dose,” Brewton said.

Band and Brewton had no disclosures. Ruma reported consulting and speaking for Hologic and consulting for Philips Ultrasound.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

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