Nicardipine Pregnancy and Breastfeeding Warnings
Nicardipine Pregnancy Warnings
Nicardipine has been assigned to pregnancy category C by the FDA. Animal studies have revealed evidence of embryotoxicity in rabbits with oral doses at 24 times the maximum recommended human dose (MRHD) based on body surface area, but not in rats with oral doses 8 times the MRHD based on body surface area; however, reduced birth weights, dystocia, reduced neonatal survival, and reduced neonatal weight gain were noted in rats at this dose. Embryotoxicity was observed at 0.27 and 0.05 times the MRHD based on body surface area following intravenous administration to pregnant rats and rabbits, respectively. In vitro data reveal evidence of decreased human myometrial contractions after exposure to nicardipine. There are no controlled data in human pregnancy. However, limited human data in pregnant women with preeclampsia or preterm labor are available. Nicardipine is only recommended for use during pregnancy when benefit outweighs risk.
At least two studies on the use of nicardipine during human pregnancy have been reported. Nicardipine was given by oral administration (20 mg TID) to 40 pregnant women with mild to moderate hypertension and by intravenous administration (no greater than 1 mcg/kg/min) to 20 pregnant women with severe preeclampsia. The drug was administered no sooner than gestation week 28 in all patients. Nicardipine effectively reduced maternal blood pressure without reducing fetal cerebral artery, umbilical artery, or maternal uterine artery blood flow. Maternal side effects were noted only after intravenous administration (headache in nine, nausea in one). Transplacental passage of nicardipine was relatively low. The mean maternal and fetal plasma drug levels were 54.6 and 4.2 ng per mL, respectively. Contrary to the data observed in animal experiments, nicardipine did not induce fetal compromise with the doses used. There were no fetal deaths, perinatal deaths, or adverse fetal effects. No adverse neonatal outcome was attributable to nicardipine. There was a 43% rate of growth-retardation, but this is comparable to the 40% rate of growth retardation that was observed in other hypertensive patients who were treated by the same investigators. In a study of 50 pregnant women with either chronic hypertension or gestational hypertension who were randomly assigned to receive nicardipine, the average umbilical artery blood flow (per Doppler velocimetry) significantly increased during therapy. There were no perinatal deaths, although significant placental infarctions were discovered in six postpartum. The average Apgar scores at 1 and 5 minutes were 7.9 and 8.9, respectively. A single case of accidental intravenous overdosage of nicardipine (20 to 25 mg/hr) during the management of hypertension during pregnancy has been reported. The fetal heart rate and umbilical, cerebral and uterine arterial Doppler velocimetry were normal during the infusion. After intravenous fluid loading and discontinuation of nicardipine, the mother gave birth via Cesarean section to a normal 3080 gram newborn with an initial Apgar score of 7/10, arterial blood pressure, heart and respiratory rates of 58/31 mmol Hg, 150 beats/min, and 50 breaths/min, respectively. The newborn recovered and was discharged from intensive care in seven days. Pregnant women treated with intravenous nicardipine for hypertension during pregnancy have reported hypotension, reflex tachycardia, postpartum hemorrhage, tocolysis, headache, nausea, dizziness, and flushing. Fetal safety results ranged from transient fetal heart rate decelerations to no side effects. Neonatal safety data ranged from hypotension to no side effects. Women treated with intravenous nicardipine during preterm labor have reported pulmonary edema, dyspnea, hypoxia, hypotension, tachycardia, headache, and phlebitis at site of injection. Neonatal side effects have included acidosis (pH less than 7.25).
Nicardipine Breastfeeding Warnings
Calculated daily infant dose was less than 0.3 mcg in 18 infants exposed to nicardipine through breast milk in the postpartum period. No side effects were observed. Possible infant exposure should be considered when nicardipine is administered to a nursing woman. In a study of 11 women who received oral (immediate release: n=4; sustained release: n=6) or intravenous (n=1) nicardipine 4 to 14 days postpartum, the milk concentration ranged 1.3 to 13.8 mcg/L. Infants received an average of 0.073% and 0.14% of the weight-adjusted maternal oral and intravenous dose; respectively. In a study of 7 women who received intravenous nicardipine for an average of 1.9 days in the immediate postpartum period as therapy for preeclampsia, nicardipine was undetectable (less than 5 mcg/L) in 82% of the 34 milk samples obtained at unspecified times. Four women who received 1 to 6.5 mg/hr of nicardipine had 6 milk samples with levels ranging from 5.1 to 18.5 mcg/L. The nicardipine level of 18.5 mcg/L was detected in a woman who received 5.5 mg/hr. The estimated maximum dose in a breastfed infant was less than 0.3 mcg/day or between 0.015% to 0.004% of the therapeutic dose in a 1 kg infant.
Nicardipine is minimally excreted into human milk. Adverse effects in the nursing infant are unlikely. However, the manufacturer recommends that due to the potential for serious adverse reactions in nursing infants, a decision should be made to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Wolters Kluwer Health and Drugs.com is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This drug information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective, or appropriate for any given patient. Multum Information Services, Inc. does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. Copyright 2000-2008 Multum Information Services, Inc. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse, or pharmacist.