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HealthInfo Waitaha Canterbury

Medicines, alcohol, drugs & breastfeeding

There is a lot of confusing and conflicting information about taking medicines when breastfeeding. This often leads to women either not taking medicine they need or giving up breastfeeding when they do not have to.

Some medicines will pass into your breast milk. The amount your pēpi (baby) receives depends on the type of medicine, how your body absorbs it, when you take it and how old your pēpi is. Premature and low-birth-weight pēpi may have more problems than other pēpi. Your pēpi can also process and excrete some medicine, so small doses of most medicines will do them no harm.

The benefits of breastfeeding your pēpi are huge, and in most cases it's safe to continue breastfeeding while you take medicine.

Safely taking medicine while breastfeeding

Young woman reading a medicine labelIf you think you may need to take medicine while breastfeeding, the following things can help to keep your pēpi baby safe. Talk to your GP, practice nurse, pharmacist or lactation consultant if you have any concerns.

Avoid any medicine that is not essential. Try non-drug therapies.

Only use medicine when you need it and it's important to your health.

If you need to take medicine, talk to your GP or pharmacist about these ideas.

It's rare that you would need to stop breastfeeding altogether. In a few cases, the medicine (for example, chemotherapy) is too toxic to continue breastfeeding.

If you need to take a medicine that prevents you breastfeeding long-term, you'll need to feed your pēpi another way. Read this information about formula feeding and get support from your health professional and a lactation consultant to guide you.

Substances to avoid while breastfeeding

Recreational drugs: Although this may seem obvious, recreational drugs (including cannabis) can harm your pēpi baby . Because there is no control over the amount of active ingredients in recreational drugs, there is no way of knowing how much is in your milk. These drugs can stay in your baby's system for many hours and can cause sleepiness, agitation, breathing problems and potentially brain damage.

If you've taken a recreational drug, it's better to feed your pēpi another way (stored or donated breast milk or formula) and ask your midwife or GP about when it's safe to breastfeed again.

Alcohol: When you drink alcohol, you easily absorb it into your breast milk – the level of alcohol in your breast milk is about the same as in your blood. If you're planning to drink alcohol, read this information to help with your feeding plan. The Feed Safe app helps you to figure out when your breast milk will be free of alcohol. It's free to download.

Young family at café for breakfastSmoking: It's best to stop smoking when you're breastfeeding, because it affects you and your baby's health. But if you do smoke, it's much better for your pēpi to be breastfed than not to be breastfed at all. Breast milk helps to strengthen your baby’s immune system from infections that are more common in smoking households, like chest and ear infections.

You can minimise the risk to your pēpi by smoking after breastfeeding, only smoking outside and by using a smoking jacket (a jacket you put on when you're smoking and take off afterwards, then leave outside). This helps to reduce the amount of smoke on your clothes that your pēpi comes into contact with.

You can read more information about why second-hand smoke is bad for your baby. Also read How to become smokefree for a list of free or cheap resources to help you quit smoking.

Caffeine: Caffeine is in coffee, tea, cola drinks, energy drinks, chocolate, some herbal products and some medicines. Having a bit of caffeine every now and then is unlikely to cause problems, but it's best to avoid having a lot when you're breastfeeding. In some cases, caffeine can make your pēpi irritable and alter their sleep patterns.

Some pēpi, particularly those under six months, are more sensitive to caffeine. If your pēpi is bothered when you have even a small amount of caffeine, you might want to stop having any for a while to see if that makes a difference. Your pēpi will probably become less sensitive to caffeine as they get older.

Common over-the-counter (OTC) medications

Talk to a pharmacist before taking any OTC medications (including any herbal or natural products) while you're breastfeeding. The following is a list of some common conditions and medications that are safe (and those to avoid):




Pain relief

Paracetamol (first choice), ibuprofen

Aspirin, codeine, extra-strength or combination medicines


Saline nasal spray and steaming, paracetamol

Pseudoephedrine (prescription only), combination preparation drugs

Allergy and hay fever

Saline nasal wash or spray, Flixonase nasal spray (fluticasone), sodium cromoglycate eye drops, loratadine, fexofenadine

Pseudoephedrine (prescription only)

Skin and thrush

Clotrimazole, MICREME H, hydrocortisone cream, moisturisers, aciclovir cream (for cold sores)


Indigestion or constipation

Gaviscon/Mylanta, lactulose, Metamucil



Bactroban ointment, penicillins and erythromycin (prescription only)

Ciprofloxacin (prescription only), tetracycline (prescription only)

Talk to your GP if you need more information.

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Written by HealthInfo clinical advisers. Last reviewed December 2021.


Page reference: 57555

Review key: HIBRF-24381