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Guaifenesin / pseudoephedrine Pregnancy and Breastfeeding Warnings

Medically reviewed by Last updated on Apr 24, 2023.

Guaifenesin / pseudoephedrine is also known as: Anatuss LA, Congestac, Decongest II, Desal II, Despec-Tab, Entex PSE, Entex T, Fenex-PSE, GP 500, Guaimax-D, Mardrops-EX, Medent-LDI, Mucinex D, Mucinex D Maximum Strength, Mucus D, Nalex, Nalex CR, Pan-Mist LA, Poly-Vent IR, Pseudovent, Respaire-60 SR, Syn-Rx, Touro LA, Zephrex, Zephrex LA

Guaifenesin / pseudoephedrine Pregnancy Warnings

Safety has not been established; use should be avoided during pregnancy.

AU TGA pregnancy category: B2
US FDA pregnancy category: Not assigned

-Pseudoephedrine use during the first trimester may be associated with gastroschisis and small intestinal atresia (SIA); data is limited and unconfirmed, risk appears to be low (only identifiable by case-control studies), and may only occur in combination products, but avoidance during the first trimester is nonetheless recommended.

Guaifenesin: A monitoring study that included 197 mother-child pairs exposed to guaifenesin in the first trimester showed an increase in inguinal hernias, but 2 other large mother-child pair groups showed no strong association between congenital defects and guaifenesin use during pregnancy.

Pseudoephedrine: Data on outcomes after pregnancy exposure are limited; two health organization analyses found 9 malformation among 902 first-trimester exposures with no specific associated defects. A monitoring study of 50, 282 mother/child pairs (3082 first trimester sympathomimetic drug exposures, 9719 any time pregnancy exposures) suggested a link to categories of minor malformations (non-life-threatening, no major cosmetic defects) including inguinal hernia and clubfoot. Pseudoephedrine may be associated with gastroschisis, but this may also be caused by maternal health factors. First trimester oral decongestant exposure or maternal smoking may increase the risk of gastroschisis, small intestinal atresia (SIA), and hemifacial microsomia. Related compounds (epinephrine, ephedrine, phenylephrine) are associated with hemorrhages, and limb and cardiovascular malformations in animal studies. Use in early pregnancy may increase vascular disruption defect risk due to the drugs vasoconstrictive effects.

There are no controlled data in human pregnancy.

AU TGA pregnancy category B2: Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals are inadequate or may be lacking, but available data show no evidence of an increased occurrence of fetal damage.

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.

See references

Guaifenesin / pseudoephedrine Breastfeeding Warnings

Caution is recommended; benefit should outweigh risk.

Excreted into human milk: Yes (guaifenesin and pseudoephedrine)

-The small amounts of pseudoephedrine (about 4.3 to 5.5% of maternal dose) may cause occasional irritability.
-A single pseudoephedrine dose acutely decreases milk production (average 24%); repeated use interferes with lactation.
-Do not use pseudoephedrine in patients with insufficient milk production or in those just establishing lactation.
-Guaifenesin levels in breast milk (after a normal parental dose) are not expected to cause harm to the infant, especially in those over 2 months old.

See references

References for pregnancy information

  1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  2. Briggs GG, Freeman RK. "Drugs in Pregnancy and Lactation." Philadelphia, PA: Wolters Kluwer Health (2015):

References for breastfeeding information

  1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  2. United States National Library of Medicine "Toxnet. Toxicology Data Network." (2013):

Further information

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