Can You Take Meclizine While Pregnant?
Yes, meclizine can be used during pregnancy and appears to be one of the safest antihistamine options available, particularly for treating nausea and vomiting in pregnancy. 1, 2, 3
Safety Profile Based on FDA Labeling and Clinical Evidence
The FDA drug label states that epidemiological studies have not generally indicated a drug-associated risk of major birth defects with meclizine during pregnancy, though animal studies showed fetal malformations in rats at doses approximately 2 times the maximum recommended human dose. 1
The most comprehensive human data comes from a large Swedish cohort study of 16,536 women who used meclizine in early pregnancy, which found no increased risk of congenital malformations—in fact, the malformation rate was actually reduced compared to unexposed women. 2 This study also found:
- Better-than-expected delivery outcomes overall 2
- Reduced rates of preterm birth, low birth weight, and small head circumference 2
- No evidence of teratogenic effects 2
Clinical Recommendations for Use
When antihistamine therapy is necessary during pregnancy, meclizine is considered the drug of first choice based on its low risk profile. 3 A 1986 clinical review specifically identified meclizine and dimenhydrinate as the antiemetics presenting the lowest risk of teratogenicity. 3
Dosing Considerations
- Standard dosing is 25 mg to 100 mg daily in divided doses 1
- Most commonly used in the first trimester for nausea and vomiting of pregnancy 2
- Effective at reducing nausea incidence (47% vs 64% in untreated groups) 4
Important Caveats and Warnings
Drowsiness is a significant side effect, occurring in approximately 31% of users compared to 13-16% in placebo groups. 4 Patients should be cautioned against:
Use with caution in patients with: 1
- Asthma (due to anticholinergic effects)
- Glaucoma
- Prostate enlargement
Comparison to Other Antihistamines in Pregnancy
The 2007 British guidelines on urticaria recommend avoiding all antihistamines in pregnancy when possible, especially in the first trimester, though none has been proven teratogenic in humans. 5 However, when treatment is necessary, chlorphenamine is often chosen in the UK due to its long safety record, while loratadine and cetirizine are FDA Pregnancy Category B drugs. 5
Meclizine has a more robust safety database than most alternatives, with over 16,000 documented exposures showing favorable outcomes. 2
Risk-Benefit Analysis
The benefits of treating nausea and vomiting in pregnancy likely outweigh theoretical risks, as the protective effects observed in the Swedish study (reduced malformations, better birth outcomes) are probably secondary to successful treatment of nausea and vomiting, which improves maternal nutrition and reduces stress. 2
Human epidemiological data consistently shows meclizine can be used without significant risk during pregnancy. 2, 3