Medications to be avoided while breastfeeding
The safety and potential toxicity of drugs and chemicals that may be excreted in breast milk is of special concern in breastfeeding mothers. Yet, there is to date an inadequate amount of information due to ethical issues surrounding the study of human lactation subjects; majority of the studies was conducted in animals, with considerable differences in the composition of milk amongst species and studies producing varying results.
Toxicity to the infant may occur if the drug enters the milk in pharmacologically significant quantities. Therapeutic doses for the mother may cause toxicity to the infants when drug concentration in the milk exceeds that in maternal plasma. However, having a pharmacologically insignificant concentration of the drug in breast milk may not necessarily be deemed harmless as future hypersensitivity may develop in the infant.
Hence, physicians should exercise clinical judgement and always weigh the risk: benefit ratio when prescribing for lactating mothers.
Clinical decision support (CDS) has the potential to identify possible risks of drugs in lactation by providing physician drug’s classification and evidence of its teratogenicity. Medication safety rules can develop from an evidence-based summary of teratogenic medication commonly prescribed to pregnant and breastfeeding women.
Some examples of classification of drug used in lactating mothers:
Drugs in Pregnancy and Lactation
Breast Feeding Recommendations
- Hold Breastfeeding
- No (limited) human data; probably compatible
- No (limited) human data; potential toxicity
- No (limited) human data; potential toxicity (mother)
The American Academy of Pediatrics
Classification of drugs used in lactating women
- ND: No data available
- C: Compatible with breastfeeding
- CC: Compatible with breastfeeding but use caution
- SD: Strongly discouraged in breastfeeding
- X: Contraindicated in breastfeeding
Information about the effect of exposure to a large number of medications during lactation can also be obtained in electronic format through consultation of several Web sites that can be linked out from CDS.
- Drugs in Breastmilk
West Midlands Regional Medicines Information Services guide is based on information compiled by the Trent and West Midlands Medicines Information Services. It contains a summary of the significance of the excretion of the commonly used drugs via breast milk, and their absorption by the infant.
- Drugs, Pregnancy, and Lactation
Archive of Ob.Gyn.News articles written by Lee Cohen, Gerald G. Briggs, and Gideon Koren.
Drugs and Lactation Database (LactMed) A peer-reviewed and fully referenced database of drugs to which breastfeeeding mothers may be exposed. Among the data included are maternal and infant levels of drugs, possible effects on breastfed infants and on lactation, and alternate drugs to consider.
- Drug Safety in Lactation
Prescriber Update Article by MEDSAFE New Zealand Medicines and Medical Devices Safety Authority. Sharon Gardiner, Drug Information Pharmacist, Christchurch Hospital and Evan Begg, Clinical Pharmacologist, Christchurch School of Medicine.
Submitted by (Jenny Ng)
1. Medications in pregnancy and lactation: part 1. Teratology. Bihimschi CS, Weiner CP. Obstet Gynecol. 2009 Jan;113(1):166-88. Review
2. Drugs in Pregnancy and Lactation 7th Edition by Gerald G. Briggs, Roger K. Freeman, Summer J. Yaffe
3. American Academy of Pediatrics Committee on Drugs: The transfer of drugs and other chemicals into human milk. Pediatrics 93(1):137-50 1994 Jan.
4. Drugs in Breastmilk http://www.ukmicentral.nhs.uk/drugpreg/qrg_p1.htm
5. Drugs, Pregnancy, and Lactation http://www.obgynnews.com/content/drugspregnancylactation
7. Drug Safety in Lactation [http://www.medsafe.govt.nz/Profs/PUarticles/lactation.htm