A 27-year-old woman in the 15th week of pregnancy has taken Somadril comp, 7-8 tablets daily, for s

Fråga: A 27-year-old woman in the 15th week of pregnancy has taken Somadril comp, 7-8 tablets daily, for several months. Is there any risk of fetal harm?

Sammanfattning: Acetaminophen, used in normal doses, is considered safe during pregnancy. There is one study indicating an increased risk of heart malformations with meprobamate, the major metabolite of carisoprodol, but this has not been confirmed in other studies. In this case, we do not consider there to be a significantly increased risk of birth defects.

Svar: Questions concerning Somadril comp (acetaminophen, carisoprodol and caffeine) and pregnancy have been answered previously on Drugline (1).

Acetaminophen, even though extensively used worldwide, has no known teratogenicity. Theoretically, the fetus can be intoxicated in the same way as the mother by over-dosage, as the substance passes the placenta barrier and the fetus already has metabolic capacity in the first trimester.

Carisoprodol is not known to be teratogenic. Some question marks remain concerning its metabolite, meprobamate. One study implies an increase of congenital heart malformations following exposure in early pregnancy (2), but this has not been confirmed in other studies. For example, in a follow-up study of 50000 pregnancies, there was no increase of birth defects among 356 children exposed to meprobamate (3,4).

There is one report to the Swedish Adverse Drug Reactions Committee (SADRAC) of suspected teratogenicity caused by meprobamate, but it has been judged not probable. 1 Drugline nr 05479 (year 1987) 2 Milkovich L, van den Berg BJ: Effects of prenatal meprobamate and chlordiazepoxide hydrochloride on human embryonic and fetal development. N Engl J Med 1975; 292: 726-728 3 Hartz SC, Heinonen OP, Shapiro S, Siskind V, Slone D: Antenatal exposure to meprobamate and chlordiazepoxide in relation to malformations, mental development, and childhood mortality. N Engl J Med 1975; 292: 726-728 4 Briggs, Drugs in pregnancy and lactation, 1986; 2nd ed: 271-272