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Nabumetone Pregnancy and Breastfeeding Warnings

Nabumetone is also known as: Relafen, Relafen DS

Medically reviewed by Last updated on Oct 29, 2019.

Nabumetone Pregnancy Warnings

Not recommended during last trimester of pregnancy.
Prior to 30 weeks gestation: Use only if potential benefit justifies the potential risk to the fetus.

US FDA pregnancy category: C

-Avoid use during third trimester as it may cause premature closure of the ductus arteriosus.
-Not recommended in women attempting to conceive as may impair female fertility.

Animal studies have demonstrated an increased risk of pre- and post-implantation loss, miscarriage, cardiac malformation, gastroschisis, and embryolethality following use of prostaglandin synthesis inhibitors in early pregnancy. Administration of nonsteroidal anti-inflammatory drugs (NSAIDs) during the third trimester of pregnancy may cause significant adverse effects, including premature closure of the fetal ductus arteriosus, oligohydramnios, fetal renal impairment, cardiopulmonary toxicity, platelet dysfunction, and pulmonary hypertension. Prolongation of bleeding time in both mother and neonate and inhibition of uterine contractions possibly delaying labor may occur during labor and delivery. There are no controlled data in human pregnancy.

NSAIDs may impair female fertility; withdrawal of NSAID therapy should be considered in women with difficulties conceiving or who are undergoing investigation of infertility.

US FDA pregnancy category C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

See references

Nabumetone Breastfeeding Warnings

Due to lack of published clinical experience during breastfeeding, other agents may be preferred.

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

Excreted into human milk: Unknown
Excreted into animal milk: Yes

Comments: The effects in the nursing infant are unknown.

See references

References for pregnancy information

  1. "Product Information. Relafen (nabumetone)." SmithKline Beecham, Philadelphia, PA.
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

References for breastfeeding information

  1. United States National Library of Medicine "Toxnet. Toxicology Data Network. Available from: URL:" ([cited 2013 -]):
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  3. "Product Information. Relafen (nabumetone)." SmithKline Beecham, Philadelphia, PA.

Further information

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