Use only if clearly needed and benefit outweighs potential risk

AU TGA pregnancy category: D
US FDA pregnancy category: Not assigned

Risk Summary: This drug can cause fetal harm when administered to pregnant women. Data from a pregnancy registry and several epidemiologic studies have shown that infants exposed in utero have an increased risk for cleft lip and/or cleft palate (oral clefts) and for being small for gestational age; in multiple animal species, this drug has demonstrated developmental toxicity, including increased incidences of fetal malformations at clinically relevant doses.

Comments:
-If a patient becomes pregnant during therapy, she should be informed of the potential hazard to her fetus; women of childbearing potential should be counseled on the use effective contraception.
-Women of childbearing potential on antiepileptic drug therapy should receive pregnancy counseling regarding the risk of fetal abnormalities. Generally, antiepileptic therapy should be continued during pregnancy, with monotherapy at the lowest effective dose whenever possible. Folic acid supplementation (5 mg) should be commenced four weeks prior to and continued for 12 weeks after conception. Women should be followed by a specialist and offered detailed mid-trimester ultrasound.
-Pregnancy Registry: The North American Antiepileptic Drug (NAAED) Pregnancy Registry collects information about the safety of antiepileptic drugs during pregnancy; enrollment information: toll-free 1-888-233-2334 or http://www.aedpregnancyregistry.org/

Animal studies in multiple species of animals have revealed evidence of developmental toxicity. Topiramate has shown teratogenicity in mice, rats, and rabbits. In humans, clinical data from a pregnancy registry and several epidemiologic studies have shown infants exposed during the first trimester have an increased incidence of major congenital malformations compared with a reference group not taking antiepileptic drugs (AED). Infants exposed in utero have an increased risk for cleft lip and/or cleft palate (oral clefts) and for being small for gestational age (SGA). SGA has been observed at all doses and appears to be dose-dependent. The prevalence of SGA is greater in infants of women who received higher doses of topiramate during pregnancy. In addition, the prevalence of SGA in infants of women who continued topiramate use until later in pregnancy is higher compared to the prevalence in infants of women who stopped before the third trimester. This drug can cause metabolic acidosis. The effect of topiramate-induced metabolic acidosis has not been studied in pregnancy; however, metabolic acidosis in pregnancy (due to other causes) can cause decreased fetal growth, decreased fetal oxygenation, and fetal death, and may affect the ability of the fetus to tolerate labor. There are no controlled data in human pregnancy.

AU TGA pregnancy category D: Drugs which have caused, are suspected to have caused or may be expected to cause, an increased incidence of human fetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects. Accompanying texts should be consulted for further details.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D and X are being phased out.

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Limited data in women with epilepsy have shown drug levels in milk similar to those in maternal plasma. The excretion of topiramate has not been evaluated in controlled studies.

Benefit should outweigh risk

Excreted into human milk: Yes

Comments:
-The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for this drug and any potential adverse effects on the breastfed infant from this drug or from the underlying maternal condition.
-If this drug is used during breastfeeding, monitor breastfed infant for diarrhea, drowsiness, adequate weight gain, and developmental milestones, especially younger, exclusively breastfed infants.
-Some authorities recommend avoiding breastfeeding during therapy with this drug.

See references