Drugs in breastmilk

AIMS Journal 2013, Vol 25 No 3

Wendy Jones looks at the reality and the evidence

We know that over 90% of women take some form of medication whilst breastfeeding – it could be anything from paracetamol for a headache to strong medication to treat infections or long-term conditions. We also know that every pack of tablets or tube of cream we pick up has a leaflet inside which says something along the lines of ‘do not use if you are breastfeeding.’ So what are we supposed to do?

Searching the internet is a minefield of personal experiences and horror stories. The Drugs in Breastmilk Helpline was set up by the Breastfeeding Network, up until that point I had been taking calls on my own home telephone!

What do the information leaflets mean?
Drug companies don’t have to submit any research on use during breastfeeding when they market a drug: it would be unethical to expose any baby in such circumstances. So the data sheet says ‘do not use if you are breastfeeding,’ then if a doctor prescribes the drug or a pharmacist sells it to a breastfeeding woman they take the full responsibility for the safety of mother and child. To do so without a clear understanding of the qualitative and quantitative information is not safe. However, we do have this information either on a theoretical level (from an understanding of the way a drug is handled by the body) or studies of where it has been used. This information is available in specialised texts, but often not the standard ones on a GP’s desk.

What drugs are not suitable for a breastfeeding mother?
The simple answer is very few! There are obvious examples such as chemotherapy, which our instincts say would not be safe. Others are ergot derivatives (such as in migraine products such as Migril), drugs which lower volume of fluid in the body (diuretics), lithium a strong drug used to treat bi-polar symptoms, some contraceptives, drugs that contain iodine or gold, or those drugs that are used to reduce or stop breastmilk supply.

What about beauty treatments?
Many mothers ask if they can have their hair coloured or straightened, have false nails fitted and spray tans applied. All these are compatible with breastfeeding.

What about contraception?
Breastfeeding mothers can take the progesterone pill (mini pill). Anecdotally, some seem very sensitive to the progesterone and notice a reduction in milk supply. Swapping the pill for barrier contraceptives can restore supply again with frequent feeding. Anyone wanting to use a depo product could try a month of tablets to test their own reactions. The combined oral contraceptive should be avoided because the oestrogen content frequently dries milk up and there is a potential effect of oestrogen on the baby.

Long term medication
If a mother is taking long-term medication any problems with use during breastfeeding should be discussed antenatally. Sadly this doesn’t always happen and it is not unusual for a midwifery unit to call the helpline to say that a mum is in labour and an answer as to safety is needed before the baby is born. Babies receive less drug through breastmilk than they do via the placenta; however, before birth, the drug is returned to the mother to metabolise (detoxify), but after birth the baby’s own liver and kidneys need to carry out this function. These organs do not work fully for the first six weeks, so prescribing for mothers with young and premature babies should be undertaken with care.

Dental treatment
Many mothers are apparently being advised by dentists to stop breastfeeding in order to have fillings or extractions of teeth. From a common sense point of view, if you have a dental injection how far does the numbness spread? Does the other side of your mouth go numb, what about your arm, the rest of your body? If the drug were being absorbed into the system then these other areas would be affected, but, in fact, the reaction stays very local. So can the anaesthetic get into breastmilk? It doesn’t in any significant quantity, so a breastfeeding mother can have a local anaesthetic injection and continue to breastfeed as normal.

Antibiotics
In a society with concerns about over-use of antibiotics there remains a lot of confusion as to whether it is a good idea to continue breastfeeding whilst taking them. Everything that we take, eat or drink passes to some degree into our milk – some in greater amounts than others. The magic thing about breastmilk for me is the speed with which women produce antibodies to infections that they encounter. So, a stranger coughing over a mum in the supermarket will elicit a response within about 20 minutes to protect the baby. If a mother develops a severe bacterial infection it may need treating with antibacterial drugs – antibiotics. We all know that some of us, after taking antibiotics, will develop vaginal thrush due to an imbalance between the natural fungal and bacterial load of our bodies, but our babies are unlikely to develop thrush because the gut balance is continually maintained by natural components of breastmilk. So we can continue to feed as normal whilst on antibiotics.

Conclusion
Far from what is believed by some healthcare professionals, we know quite a lot about the safety of the majority of drugs taken by breastfeeding mothers. I’m always happy to answer questions via my website www.breastfeeding-and-medication.co.uk or on my Facebook page Breastfeeding-and-Medication.

Never take the patient information leaflet as meaning that you, or mothers you are caring for, need to stop breastfeeding to take a medication as this is rarely necessary. We need to balance the need of the baby to receive optimal nutrition, the need for the mother to take a particular medication and the risks to both mother and child of stopping breastfeeding.

Wendy Jones, PhD MRPharmS

Further resources

Jones W (2013) Breastfeeding and Medication. Routledge. London.

Hale T (2012) Medications and Mothers’ Milk, 15th Edition. Hale Publishing. London.