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Phentermine / topiramate Pregnancy and Breastfeeding Warnings

Phentermine / topiramate is also known as: Qsymia

Medically reviewed by Last updated on Apr 24, 2019.

Phentermine / topiramate Pregnancy Warnings

Use during pregnancy is contraindicated as this drug can cause fetal harm.

US FDA pregnancy category: X

-Females of reproductive potential should be advised to avoid pregnancy through abstinence or by using effective contraception during therapy.
-A negative pregnancy test should be obtained before treatment initiation and monthly thereafter in females of reproductive potential.

Data from pregnancy registries and epidemiology studies indicate an up to 5-fold increased risk of oral clefts (cleft lip with or without cleft palate) with first trimester exposure to topiramate. Animal studies with clinically relevant doses of topiramate revealed embryofetal toxicity, including craniofacial defects; increased mortality; reductions in body weight and skeletal ossification; delayed physical development; and malformations in limbs, ribs, and vertebrae. Evidence of maternal toxicity, such as decreased body weight gain and mortality, were also observed in animal studies with topiramate. Animal reproduction studies have not been conducted with phentermine.

Combination phentermine and topiramate treatment in animals at doses approximately 5 to 6 times the maximum recommended human dose caused offspring toxicity and significantly lower maternal body weight gain. Offspring effects included lower survival after birth; increased limb and tail malformations; reduced body weight; and delayed growth, development, and sexual maturation without affecting learning, memory, fertility, and reproduction.

This drug can cause metabolic acidosis. Metabolic acidosis in pregnancy can result in decreased fetal growth, decreased fetal oxygenation, fetal death, and may affect the ability of the fetus to tolerate labor. If this drug is used during pregnancy or if a patient becomes pregnant while taking this drug, treatment should be discontinued immediately and the patient should be apprised of the potential hazard to a fetus.

To monitor the outcomes of pregnant women exposed to this drug, a pregnancy registry has been established. Physicians and pregnant women are encouraged to register by calling 1-888-998-4887.

US FDA pregnancy category X: Studies in animals or humans have demonstrated fetal abnormalities and/or there is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience, and the risks involved in use of the drug in pregnant women clearly outweigh potential benefits.

See references

Phentermine / topiramate Breastfeeding Warnings

A decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Excreted into human milk: Unknown
Excreted into animal milk: Data not available

Comments: This drug may be present in human milk because topiramate and amphetamines are excreted in human milk. Phentermine has pharmacologic activity and a chemical structure similar to amphetamines.

See references

References for pregnancy information

  1. "Product Information. Qsymia (phentermine-topiramate)." Vivus Inc, Mountain View, CA.

References for breastfeeding information

  1. "Product Information. Qsymia (phentermine-topiramate)." Vivus Inc, Mountain View, CA.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.