Safety of Drugs in Breastmilk

I saw a GP when I had an infection in my stitches (tear) after birth. Was told by the GP that I needed to take antibiotics and that that meant stopping breastfeeding. Wasn’t given any alternative or advice on stopping, just told the two were not compatible. Ended up stopping cold turkey because I knew no difference and then got mastitis…

On the flip side I had a very positive experience with a GP more recently who was more than happy to check all my prescriptions were breastfeeding safe…Left me feeling immensely proud and positive for a change.

SB, Mother

by Dr Wendy Jones BSc MSc PhD MRPharmS, Specialist Pharmacist with expertise in Drugs in Breastmilk 

Many, if not almost all mothers need to take medication at some time when they are breastfeeding. These may be acute courses eg. antibiotics for an infection, or chronic use eg. analgesics or anti-inflammatories for ongoing pain of rheumatoid arthritis.

There is much concern over the prescription and sale of medication for the breastfeeding mother as this involves the exposure of a third person– the nursing infant. Commonly available reference texts eg. the British National Formulary (BNF) contain little if any quantitative data on which to make informed decisions. The Summary of Product Characteristics (SPC) of the vast majority of drugs recommends that they are not used during lactation. This does not imply risk, just that the manufacturers are not required to take responsibility and consequently do not do so.

This means that healthcare professionals are frightened by having to take responsibility for all drugs used by mothers when they are breastfeeding. Mothers are frightened by the written words in the packs even if they have been told that the drug is safe by their doctor or pharmacist. So what happens? Either the mother decides not to take the medication or she stops breastfeeding. Is this necessary? No it isn’t if the evidence behind safety is examined. If after looking at this, the healthcare professional and mother, decide the risk is too great then that is an informed decision. If a mother is told she needs to stop breastfeeding despite her choice to continue or the difficulties for her in doing so are not taken into consideration, then that is not acceptable.

As healthcare professionals we need to understand that not all babies will suck from a bottle. More importantly we need to recognise that formula milk is not the same as breastmilk and that interrupting breastfeeding may have irreversible consequences to the detriment of the mother and baby. This is a recommendation from NICE in the public health guidance Maternal and Child Nutrition (NICE PH11, see below).

With thanks to Dr Jones for her contribution to this website. Her own website Breastfeeding and Medication can be found here.

Further Information 

Many drugs can be safely taken while breastfeeding. Drugs will usually need to be prescribed off label with the prescriber taking responsibility, and the following clinical resources provide evidence based information to support the clinician in discussing medication with a breastfeeding mother.

It must also be stressed that, in general, the guidance and the information provided for individual drugs in the resources below only applies to full-term, healthy infants.  Additional care must be taken, and advice sought, if the infant is pre-term, low-birth weight or has compromised health at birth.

NICE Guideline PH11: Maternal and Child Nutrition recommends supplementary sources of information should be consulted regarding the prescribing of drugs to breastfeeding mothers, and that the BNF Appendix should only be used as a ‘guide’.

Clinical Resources 

The Breastfeeding Network Drugs in Breastmilk Information Service Support for parents and healthcare professionals providing evidence based information on the safety of drugs in lactation via factsheets, email and a dedicated Facebook page.

The Breastfeeding Network: Drugs in Breastmilk Information Factsheets The Breastfeeding Network’s Specialist Pharmacist Dr Wendy Jones has produced a range of factsheets compiling the evidence base for the use of many drugs in lactation, suitable for parents to refer to and also accessible to healthcare professionals.

UK Drugs in Lactation Advisory Service (UKDILAS) Provided by UKMi (part of the NHS Specialist Pharmacy Service) supporting safe use of medicines during breastfeeding. Every drug within the BNF has been risk assessed and individual drug entries included on the website. More detailed information is provided for some medicines via UKMi Q&As.

UK Drugs in Lactation Advisory Service/Midlands Medicines: Breastfeeding and Medicines- General Principles Principles of safe prescribing for breastfeeding mothers.

Lactmed (US National Library of Medicine) Toxnet The US National Library of Medicine Toxicology Data Network (Toxnet) Drugs and Lactation Database. A smart phone app is also available.

Best Use of Medicines in Pregnancy (BUMPS) Information for patients on the safety of drugs in pregnancy provided by the UK Teratology Information Service (UKTIS). UKTIS is funded by Public Health England on behalf of the UK Health Departments.

NHS Website: Breastfeeding and Medicines Patient information on the basics of the safety of drugs in breastmilk.

NICE Guideline CG192 Antenatal and Postnatal Mental Health: Clinical Management and Service Guidance (Updated April 2018) Guidance on the principles of mental health care, including prescribing, pre-pregnancy, in pregnancy and the postnatal period. Section 1.4, 1.8 and 1.9 have detailed information on prescribing issues. Key Clinical Priorities with regards to prescribing are outlined here.

Recommended Reading

  • Breastfeeding and Medication Jones W, Routledge (2nd Ed, 2018) ISBN-13: 978-1138298323

 Published April 2017, Reviewed 11th June 2021