High-dose carisoprodol during pregnancy and lactation

OBJECTIVE: To report a case of use of high-dose carisoprodol during pregnancy and breast-feeding. CASE SUMMARY: A 28-year-old woman with severe back muscle spasm took carisoprodol 2800 mg/day before and throughout an uncomplicated pregnancy and while exclusively breast-feeding her infant during the first month after birth. Serum drug concentrations of carisoprodol and the active metabolite meprobamate were measured in the mother and infant. Concentrations of these agents also were measured in breast milk. Developmental toxicity was not observed in the near-term infant, whose birth weight was at the 10th percentile for gestational age. Only slight sedation was noted in the infant during breast-feeding, and no signs or symptoms of withdrawal were noted when nursing was stopped. DISCUSSION: Carisoprodol and meprobarnate are excreted into breast milk. Although the published human pregnancy data are limited to 15 cases, carisoprodol does not appear to cause developmental toxicity (growth restriction, structural anomalies, functional/neurobehavioral deficits, or death), even when the mother is taking high doses. No signs or symptoms of withdrawal were noted in our infant or in a previously published case when breast-feeding was stopped. Longterm follow-up has not been conducted in exposed infants, and the possibility of functional/neurobehavioral I deficits appearing later in life cannot be excluded. CONCLUSIONS: Except for mild sedation, no other toxicity was observed in a near-term infant exposed to carisoprodol throughout gestation and during breast-feeding in the first month after birth.