Last updated on Jun 11th, 2021 at 11:42 am

Many women can share how they had to stop breastfeeding because they developed a medical condition for which they needed to take medication. Others were told to stop feeding for a certain period after being on the medication, without any thought given to what this would do to their milk supply.

Sadly, in many of these cases the halting of breastfeeding was unnecessary. Medication while breastfeeding is one of the topics healthcare professionals like doctors and pharmacists are generally the least informed about.

The opposite is also true. Sometimes breastfeeding problems like nipple thrush and mastitis are not treated correctly, simply because the wrong medications and dosages were prescribed. Something completely treatable can become a far more serious and drawn-out problem than was ever necessary.

ALSO SEE: Avoid these 8 things when breastfeeding

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But why is this such a challenge?

Medication in a mom’s milk is almost a discipline on its own. Before a medication can be declared safe to use in humans, numerous drug trails are run to ensure that we know how it works and what all the possible side-effects are.

These trials would be unethical in pregnant women and breastfeeding mothers, as we cannot take a chance to cause any harm to a baby. As a result, the information that we use to determine safety are gathered from moms who used the medication anyway. Far less information is available than in typical drug trials. For this reason, the package inserts of most medications will simply say “safety in pregnancy and lactation is not established”.

But depending on the drug, how long it has been on the market and how commonly it’s used, the information that we do have may very well be enough.

Doctors and pharmacists are often over-cautious when advising breastfeeding mothers on medication. The wonderful truth is that our breasts are far more effective in blocking harmful substances than the placenta is in pregnancy. Any drugs that do enter a mother’s breastmilk also need to go through baby’s digestive system and liver, which means that very often, little of it actually enters the baby’s blood stream.

Medication risk categories

Dr Thomas Hale is an expert in this field. He divides medication in the following lactation risk categories:

  • L1 (safest) – These are drugs we have a lot of information on and prove that it is completely safe for mom and baby.
  • L2 (safer) – There is limited studies on these drugs, but what we do have show that risk is unlikely.
  • L3 (probably safe) – Studies show some effects on baby. However, it is still considered to be more beneficial to continue breastfeeding on these medications than it is to stop. All new drugs are put into this category. They should only be used if really needed.
  • L4 (possibly hazardous) – There is evidence that these medications are harmful to baby or that it may influence a mom’s breastmilk production. But the benefits of breastfeeding may still make these risks acceptable.
  • L5 (hazardous) – These drugs are definitely harmful and a mom would have to stop breastfeeding.

So how do you know?

In any event, it’s worthwhile to find a doctor and pharmacist who are pro breastfeeding and informed about breastfeeding. This may not be as easy as it sounds though.

Remember, you have the right to ask for information. You can ask your doctor or pharmacist to use the apps Lactmed or Infantrisk to check the lactation risk categories of any prescribed medication. They may not be aware of these resources and you may indirectly help other mothers as well.

If any practitioner suggests that you stop breastfeeding due to a prescribed medication, a second opinion would be a good idea. This is too big a sacrifice to make if you are not really sure that it is necessary.

If it seems that a drug is truly harmful, speak to a lactation consultant. She may be able to help you find ways to manage the situation until breastfeeding is safe again.

A few common drugs to avoid while breastfeeding

  • Needless to say any recreational drugs like cocaine and marijuana should never be used while breastfeeding, for various reasons.
  • Pseudoephidrine – This is a common ingredient in over-the-counter colds and flu medication, and can reduce your milk supply.
  • Oral contraceptives that contain oestrogen can suppress milk supply.
  • Progesterone-only options like the mini-pill or the contraceptive injection are considered safe, but should not be used before at least 6 weeks after the baby’s birth – in this vulnerable period it can still affect your milk supply.
  • Most weight-loss medications are not safe while breastfeeding.
  • Do not take any medication containing aspirin as it may trigger a very serious condition named Reye’s Syndrome in a baby. In fact, aspirin should not be used in children under 12 years of age.
  • Any pain medication containing codeine should be avoided, especially if your baby is still small. It may make baby sleepy and can have a negative effect on their feeding patterns.
  • Lastly, remember that herbal medications can also have side-effects, so don’t just use any product because it’s considered natural.