Tegretol Use In Pregnancy & Lactation

Women of childbearing potential: Women of childbearing potential should use reliable contraception during treatment with carbamazepine and for 2 weeks after the last dose.
Due to enzyme induction, Tegretol may abolish the therapeutic effect of drugs containing oestrogens and/or progesterones, which may lead to failure of contraceptive protection. Women of childbearing potential should therefore use alternative effective and reliable contraceptive methods while being treated with Tegretol.
Pregnancy: There is clear evidence of risk to the human fetus. Tegretol should therefore not be used during pregnancy unless absolutely necessary.
As with other antiepileptic drugs, ingestion of carbamazepine during pregnancy has been associated with reports of various types of embryonic malformation, including spina bifida and other congenital anomalies such as craniofacial defects, cardiovascular malformations, hypospadias and anomalies involving various body systems. It should, however, be borne in mind that developmental disorders, including malformations, are observed 2-3 times more frequently in the offspring of epileptic mothers than in those of healthy controls. The extent to which these effects can be attributed to carbamazepine or to the underlying disease has not been fully elucidated.
Based on data from the North American Pregnancy Registry, the rate of major congenital anomalies, defined as a structural abnormality with surgical, medical or cosmetic importance, diagnosed within 12 weeks of birth, was 3.0% (95% CI 2.1 to 4.2%) among mothers exposed to carbamazepine monotherapy in the first trimester, and 1.1% (95% CI 0.35 to 2.5%) among pregnant women not taking any antiepileptic drug (relative risk 2.7, 95% CI 1.1 to 7.0%).
The nature of, and need for, treatment should always be carefully planned, and reassessed, in epileptic women wishing to conceive. Necessary antiepileptic therapy should not be withdrawn during pregnancy, as deterioration of the condition may have a negative impact on the development of the fetus.
Between days 20 and 40 of pregnancy in particular, the dose administered should be as low as possible. Malformations are probably triggered by peak plasma concentrations, and during this period in particular the total daily amount should therefore be given in several small divided doses spread over the day. Monitoring of plasma levels is recommended. The plasma concentration may be maintained at the lower end of the therapeutic range (4-12 μg/ml), provided that seizure control is maintained. There is evidence to suggest that the risk of malformations with carbamazepine is dose-dependent, i.e. at a dose <400 mg per day, the rates of malformations were lower than with higher doses of carbamazepine.
Throughout pregnancy and postpartum, the patient must be kept under close surveillance (monitoring of serum levels and EEG). Plasma levels should lie at the lower end of the therapeutic range (3-7 μg carbamazepine/ml). The risk of malformations is higher with combination therapy, so combination with other antiepileptics, or other drugs, should be avoided in order to further reduce risks. Monotherapy is recommended. There is evidence to suggest that the risk of malformations with carbamazepine in polytherapy may vary depending on the comedications used, and may be higher in polytherapy combinations that include valproate.
Due to the enzyme-inducing properties of carbamazepine, administration of folic acid is generally recommended before and during pregnancy (prevention of neural tube defects). It is also necessary to administer vitamin K to the mother during the final weeks of pregnancy, and postpartum to the neonate, in order to avoid haemorrhagic complications.
There have been some reports of seizures and/or respiratory depression in neonates whose mothers took Tegretol or another anticonvulsant shortly before or during the birth. Regular intake of carbamazepine by the mother can also produce withdrawal symptoms (vomiting, diarrhoea and/or nutritional disturbances) in the neonate.
Breastfeeding: In postnatal rat studies, adverse effects on the offspring of carbamazepine-treated dams were observed (see Pharmacology: Toxicology: Preclinical data under Actions).
Carbamazepine is excreted in breast milk at concentrations approx. 25-60% of those found in the plasma. The benefits of breastfeeding generally outweigh the risks of possible adverse effects. Breastfeeding should be discontinued if the infant is found to have poor weight gain, excessive drowsiness or an allergic skin reaction. There have been some reports of cholestatic hepatitis in babies exposed to carbamazepine before birth or during breastfeeding. Breastfed infants of mothers treated with carbamazepine should therefore be carefully observed in particular for adverse effects on the hepatobiliary system.