Can I take mefenamic acid while pregnant or breastfeeding?

8.1 Pregnancy Risk Summary Use of NSAIDs, including mefenamic acid, can cause premature closure of the fetal ductus arteriosus and fetal renal dysfunction leading to oligohydramnios and, in some cases, neonatal renal impairment. Because of these risks, limit dose and duration of mefenamic acid capsules use between about 20 and 30 weeks of gestation, and avoid mefenamic acid capsules use at about 30 weeks of gestation and later in pregnancy (see Clinical Considerations, Data) . Premature Closure of Fetal Ductus Arteriosus Use of NSAIDs, including mefenamic acid capsules, at about 30 weeks gestation or later in pregnancy increases the risk of premature closure of the fetal ductus arteriosus. Oligohydramnios/Neonatal Renal Impairment Use of NSAIDs at about 20 weeks gestation or later in pregnancy has been associated with cases of fetal renal dysfunction leading to oligohydramnios, and in some cases, neonatal renal impairment. Data from observational studies regarding other potential embryofetal risks of NSAID use in women in the first or second trimesters of pregnancy are inconclusive.

Prescribing label, section “8.1 Pregnancy” (opening excerpt): Mefenamic acid (oral), Bryant Ranch Prepack. Read the full section on DailyMed. Quoted verbatim; US labels are written for US prescribers and patients.

Because there is little published experience with mefenamic acid during breastfeeding and it is potentially toxic, other agents may be preferred, especially while nursing a newborn or preterm infant.

“Summary of Use during Lactation”, LactMed record “Mefenamic Acid” (LM166), quoted verbatim. Everything LactMed reports about Mefenamic Acid while breastfeeding.

8.2 Lactation Risk Summary Mefenamic acid is present in human milk in low amounts and may be transferred to breastfed infants. There are no available data on the effects of mefenamic acid on the breastfed infant or on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for mefenamic acid and any potential adverse effects on the breastfed infant from the mefenamic acid or from the underlying maternal condition.

Prescribing label, section “8.2 Lactation”: Mefenamic acid (oral), Bryant Ranch Prepack. Label on DailyMed. Quoted verbatim; US labels are written for US prescribers and patients.