Breastfeeding and your medicines

Don't give up on breastfeeding just because you need to take medicine – instead find out whether it is safe to keep breastfeeding. Never stop any medicine suddenly, check first with your doctor or pharmacist as stopping some medicines suddenly can be dangerous and make you unwell.

This article is intended as a general guide only. Get advice from your pharmacist, midwife or doctor if you have any questions or concerns.

Most medicines are safe to take while you are breastfeeding because they don't pass into your breast milk. Even if the medicine does enter your milk, it is usually in such a small amount that it won't affect your baby.

However, occasionally medicines are not good to take while breastfeeding. This can be because they have a risk of side effects for your baby, or because they might decrease your milk production.

Before your doctor prescribes a medicine for you, make sure they know you are breastfeeding, and ask them to check and discuss with you any information about continuing to breastfeed while taking this medication.

Breastfeeding mothers rarely have to stop breastfeeding due to taking medicine. However, it is important you get advice from your doctor or pharmacist. They will help you to weigh up the risks and benefits of taking the medicine with any risks for your baby.

You should take special care if your baby was premature, is sick or is taking medicine themselves.

If you think you may need to take medicine while breastfeeding, working through the following steps can help to keep your baby safe. Talk to your doctor, midwife, Plunket nurse or pharmacist if you have any concerns.

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1. Avoid any medicine that's not essential

Use medicine only when you need it and it's important to your health. Avoid any medicine that's not essential.

2. If you do need to take medicine, talk to your GP or pharmacist first

They can advise you on choosing the right medicine and on how to do the following:

• Take the lowest recommended dose for the shortest time possible.
• Avoid extra-strength or long-acting medicines for short-term conditions, and medicines with more than one ingredient.
• Take the medicine in a form that doesn't enter your milk or only in minimal amounts, eg, it may be available as a cream, ointment or spray.
• Feed your baby just before you take the medicine, as this limits the amount passed into your breast milk.

3. Look up the safety of your medications using a trusted online database:

• LactMed(external link)
• E-lactancia(external link)
• MommyMeds App(external link)

There are some situations where the medicine is necessary but makes it too harmful for you to continue breastfeeding, such as chemotherapy. Your will need to find other ways to feed your baby safely if you are taking one of these medicines long-term: 

• some anticancer medicines (chemotherapy)
• some immunosuppressants (with exceptions, eg, azathioprine in some circumstances)
• gold salts
• amiodarone
• lithium
• ergotamine. 

Read more about what to do if you can't breastfeed and feeding your baby infant formula.

Some medicines can reduce or increase your milk supply.

The combined oral contraceptives (the pill) are best avoided in the early stages of breastfeeding because oestrogen (usually ethinyloestradiol) reduces the volume of milk production. Breastfeeding women who need to take an oral contraceptive are usually prescribed a progestogen-only pill.

Common cough and cold decongestants can also lower milk production and are best avoided during breastfeeding.