FALL AND WINTER WILL BRING UP MORE QUESTIONS ABOUT WHICH COUGH, COLD, AND ALLERGY MEDICATIONS to use during pregnancy and breastfeeding. Recommend trying nondrug options first, a humidifier or vaporizer, plenty of fluids to help thin mucus, and nasal saline for congestion. Suggest other options when this isn't enough...
Nasal steroids. These don't seem to be risky in pregnancy. Suggest budesonide (Rhinocort) or beclomethasone (Beclo). Recommend using the lowest effective dose for breastfeeding moms because some of the steroid may be excreted in breast milk.
Antihistamines. Recommend chlorpheniramine during pregnancy, it has the best evidence. Explain that loratadine (Claritine, etc) or cetirizine (Zyrtec, etc) are okay in the second or third trimester. For breastfeeding mothers, suggest taking the antihistamine at bedtime after the last feeding to reduce potential effects in the baby. Caution that antihistamines might decrease the milk supply.
Decongestants like pseudoephedrine, oxymetazoline. These seem to have a very low risk of causing malformations and can be used, but advise avoiding them in the first trimester. Also nasal decongestants (Otrivin, etc) can be prescribed. BUT don't assume that nasal decongestant are risk-free. These are absorbed from the nasal mucosa especially oxymetazoline (Afrin, etc). Decongestants are likely okay in breastfeeding. But caution that they may cause irritability in the baby and decrease milk production. Avoid if milk production insufficient or not established. May cause irritability.
Antitussives/expectorants. Guaifenesin and dextromethorphan are okay to use in pregnancy, but aren't very effective. Avoid products with alcohol during pregnancy and breastfeeding. Caution to AVOID cough medications contain codeine. It's associated with malformations in pregnancy and can cause opioid toxicity in some breastfed infants.
REFERENCES
Rozek, P. (2006). Pregnancy and OTC Cough, Cold, and Analgesic Preparations. [online] Uspharmacist.com. Available at: https://www.uspharmacist.com/article/pregnancy-and-otc-cough-cold-and-analgesic-preparations
Yau, W.-P., Mitchell, A.A., Lin, K.J., Werler, M.M. and Hernández-DÃaz, S. (2013). Use of Decongestants During Pregnancy and the Risk of Birth Defects. American Journal of Epidemiology, 178(2), pp.198–208. Available at: https://pubmed.ncbi.nlm.nih.gov/23825167
Henderson, E. and Mackillop, L. (2011). Prescribing in pregnancy and during breast feeding: using principles in clinical practice. Postgraduate Medical Journal, [online] 87(1027), pp.349–354. Available at: https://pmj.bmj.com/content/87/1027/349.long