The Basics
What is Cimetidine?
Used to treat ulcers of the stomach and intestines and prevent them from returning. Also used to treat certain stomach and throat problems caused by too much stomach acid.
Brand names for Cimetidine
Tagamet
How Cimetidine is classified
Anti-Ulcer Agents, Histamine H2 Antagonists, Gastrointestinal Agents
Cimetidine During Pregnancy
Cimetidine pregnancy category
Category B
Note that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.
What we know about taking Cimetidine while pregnant
Tagamet HB is not associated with pregnancy or fetal risk. When injected into the bloodstream during labor, no negative outcomes were noted, however, use during the first trimester of pregnancy has not been adequately studied. Tagamet HB crosses to the fetus via diffusion through the placenta.
Taking Cimetidine While Breastfeeding
What are recommendations for lactation if you're taking Cimetidine?
Limited information indicates that maternal cimetidine results in infant dosages much less than those given directly to neonates. Cimetidine would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months. However, because of its potential for causing hepatic enzyme inhibition, other drugs might be preferred.
Maternal / infant drug levels
Limited information indicates that maternal cimetidine results in infant dosages much less than those given directly to neonates. Cimetidine would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months. However, because of its potential for causing hepatic enzyme inhibition, other drugs might be preferred.
Possible effects of Cimetidine on milk supply
Histamine H2-receptor blockade is known to stimulate prolactin secretion. In addition, cimetidine may have additional, nonspecific actions that stimulate prolactin secretion.[2] Oral cimetidine doses of 400 mg 4 times daily increased serum prolactin by 50 to 112% in 6 patients. Cimetidine caused dose-related gynecomastia and galactorrhea in men and nonnursing women.[3][4][5] The prolactin level in a mother with established lactation may not affect her ability to breastfeed.
Possible alternatives to Cimetidine
Famotidine, Nizatidine, Omeprazole, Pantoprazole, Ranitidine, Sucralfate.
List of References
Lactation sources: Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK501922/
1. Somogyi A, Gugler R. Cimetidine excretion into breast milk. Br J Clin Pharmacol. 1979;7:627-9. Letter. PMID: 465286
2. Knigge UP. Histaminergic regulation of prolactin secretion. Dan Med Bull. 1990;37:109-24. PMID: 2188799
3. Delle Fave FG, Tamburrano G, De Magistris L et al. Gynaecomastia with cimetidine. Lancet. 1977;309:1319. PMID: 68422
4. Bateson MC, Browning MCK, Maconnachie A. Galactorrhoea with cimetidine. Lancet. 1977;310:247-8. Letter. PMID: 69853
5. Garcia Rodriguez LA, Jick H . Risk of gynaecomastia associated with cimetidine, omeprazole, and other antiulcer drugs. BMJ . 1994;308:503-6. PMID: 8136667
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
