For specific guidance on this topic, please speak to your personal doctor. This article is intended as a general guide and should not be considered medical advice.

It is not usually necessary or recommended for a mother to stop breastfeeding due to her medication needs. However, this can be a confusing area for parents, as drug manufacturers are not required to provide any clinic data on their safety for use by lactating mothers. The information insert will routinely state “Do not take if you are breastfeeding” or “Please consult your GP or pharmacist before taking this drug if you are breastfeeding”. This is not a statement of the danger of a drug, but it relates to its not having been tested and licenced for breastfeeding mothers.

The GP (or other prescribing doctor) must therefore take responsibility for the prescription. Questions that are important for consideration include:

Urgency and necessity of treatment for the mother.
Age and maturity of the baby: the kidneys are not fully functional at birth, and premature babies are particularly vulnerable.
Volume of breastmilk ingested by the baby: a six-week-old, fully breastfed baby will be drinking a greater volume (therefore more exposure) than a two-year-old who feeds once or twice per day.
Known information on the drug with regards to lactation.

Although trials are not done on breastfeeding mothers, there are known factors about the drugs that can influence their safety in breastmilk. These include:

If this is a drug that is routinely given to children, it is usually considered safe for breastfeeding mothers.
Drugs with a short half-life are preferred as there is less buildup.
Drugs that are highly protein-bound are less likely to enter the milk.
Drugs that have a low plasma-to-milk ratio are safer, as it means that less drug transfers into the milk.
Drugs that have been previously and commonly prescribed, without negative impact, to lactating mothers are preferred.

There are specific resources like The Breastfeeding Network that give specific, reliable information regarding commonly prescribed medications. It can be useful to take the relevant fact sheet to your doctor when discussing a potential prescription’s safety.

It is important to recognise the advantages of breastfeeding and, therefore, the risks of unnecessary early weaning when considering medications. A blanket recommendation to wean due to the mother’s medical needs is not a neutral choice, and this harm must be balanced with any known side effects for the infant of the medication.

Can I take any medication while I breastfeed?

Can you take medication while breastfeeding? Unii Expert Wendy Lever has some answers.