Is carisoprodol compatible with breast-feeding?

Fråga: Is carisoprodol compatible with breast-feeding?

Sammanfattning: Carisoprodol and its metabolite meprobramate are excreted in human breast milk. No adverse effects were observed in one breast-fed infant whose mother was treated with carisoprodol. However, due to limited data breast-feeding during treatment with carisoprodol cannot be recommended until more clinical data are available.

Svar: Carisoprodol is a centrally acting muscle relaxant used to treat painful musculoskeletal conditions. Carisoprodol has a half life of four hours and is metabolised nearly completely to meprobamate, which has an elimination half life of ten hours. The published data on the transfer of carisoprodol into breast milk is very limited. The milk concentration of the drug has been reported to be two to four times the maternal plasma concentration (1,2). The peak plasma concentration after administration of 350 mg carisoprodol was 4.7 microgram/mL and based on that value the infants estimated relative dose would be 5-10% of the maternal weight-related single dose. In a case report on one woman treated carisoprodol 2100 mg daily, the concentrations of carisoprodol and the metabolite meprobamate were measured in breast milk on four consecutive days (3). The average milk concentrations were 0.9 microgram/mL for carisoprodol and 11.6 microgram/mL for meprobamate. The infant´s relative dose was calculated to 4.1% of the weight-adjusted maternal dose. No adverse effects were observed in the infant, but the infant was partly fed with formula because of insufficient maternal milk production. The manufacturer has no further data on carisoprodol and breast-feeding (4). 1 Micromedex(R) Healthcare Series: Micromedex Inc., Englewood, Colorado (Edition expires) 2 Elenbaas JK. Centrally acting oral skeletal muscle relaxants. Am J Hosp Pharm 1980;37(10):1313-23. 3 Nordeng H, Zahlsen K, Spigset O. Transfer of carisoprodol to breast milk. Ther Drug Monit 2001;23:298-300. 4 Karin Ahlstrand, Alpharma, personal communication.