Breastfeeding has long been widely recognised as the optimal source of nutrition for infants, as it provides numerous health benefits for them.
Since 1981, the World Health Organization (WHO) has recommended exclusive breastfeeding for the first six months of an infant’s life, followed by continued breastfeeding alongside complementary foods for up to two years of age or beyond.
Nevertheless, many mothers express concerns about the safety of taking medicines during breastfeeding, with the key one being: Do all medicines pass into breast milk?
Depends on the drug
Although in theory, most medicines are transferred into breast milk to some extent, the majority of commonly-used medicines by breastfeeding women can be taken safely.
This is as the amount of medicine present in breast milk is usually small and unlikely to cause harm to the infant.
In addition, breastfeeding women generally try to avoid taking medicines whenever possible and use them only when necessary.
Nevertheless, exceptions apply to certain medicines that may be present in high concentrations in breast milk or may exert harmful effects even at low concentrations.
Therefore, each medicine must be evaluated on an individual basis.
The amount of a medicine that passes into breast milk depends on its pharmacokinetic properties.
These include the molecular size of the medicine, the proportion of the drug that remains unbound in the bloodstream, and the duration for which the drug stays in the circulation.
When an infant is exposed to a medicine through breast milk, several factors determine whether side effects may occur.
These include:
- Timing of the dose – feeding baby just before mother takes the medicine results in the lowest possible drug exposure
- Volume of breast milk consumed – a lower intake is associated with a reduced risk of side effects
- Age of the infant – the younger the baby, the more underdeveloped their main organ functions are likely to be, which could affect how much of the medicine is absorbed, distributed or excreted.
Safe to use
There are times when breastfeeding women may need to take medicines to treat short-term illnesses or long-term chronic conditions.
Examples of medicines that are generally considered safe for use during breastfeeding include:
- Pain relievers
These medicines are generally recommended for short-term use and only when necessary.
Examples are paracetamol, mefenamic acid and ibuprofen.
- Antimicrobial medicines
These can be safely used to treat infections when taken at standard therapeutic doses.
Examples are amoxicillin, ampicillin, cloxacillin, cefuroxime, cephalexin and erythromycin.
- Antihistamines
These can be safely used to treat rhinitis or allergic reactions.
Examples are chlorpheniramine, loratadine and fexofenadine.
However, some antihistamines, particularly first-generation medications, may cause drowsiness, and should therefore be used with greater caution.
- Contraceptive medicines
Those safe to use are medicines that contain only progestin as the active ingredient.
- Medicines for postpartum depression or anxiety
Examples are paroxetine, sertraline and fluvoxamine.
- Epilepsy medicines
Examples are lamotrigine and carbamazepine.
- Fibre-based laxatives
These are preferred if needed during breastfeeding as other types of laxatives may cause diarrhoea in baby if taken in high doses by mother.
- Vitamin and mineral supplements
Examples are iron and vitamin B.
Be cautious
While most over-the-counter and commonly prescribed medicines are safe to use during breastfeeding, lactating mothers should still exercise caution when taking certain medicines.
For example, decongestant medicines that contain ingredients such as pseudoephedrine or phenylephrine, which are commonly used to relieve nasal congestion associated with colds, flu or allergic rhinitis.
These medicines may reduce breast milk supply.
As a safer option, breastfeeding mothers may consider using saline nasal drops, nasal sprays or a humidifier to help relieve nasal congestion instead.
There are other medicines also known to reduce or suppress breast milk production.
These include ergometrine, diuretics such as hydrochlorothiazide, and oestrogen-containing oral contraceptive pills.
Mothers are advised to consult their doctor or pharmacist for further information and appropriate alternatives.
For mothers with diabetes, medicines from the sulphonylurea group, such as gliclazide, should be avoided or used with caution during breastfeeding due to the risk of hypoglycaemia (low blood sugar) in the infant.
Certain antibiotics, such as chloramphenicol, tetracycline, metronidazole and quinolone antibiotics, should be avoided during breastfeeding or used only under strict medical supervision.
These medicines can pass into breast milk and may cause side effects, such as gastrointestinal disturbances or diarrhoea, in the infant.
Cancer treatments such as chemotherapy medicines, including metabolites, as well as radioactive medicines, should be avoided during breastfeeding because these substances can pass into breast milk and pose significant risks to the infant.
Medicines from the benzodiazepine group, which are commonly used to treat anxiety and insomnia, as well as opioid medicines prescribed for chronic pain may cause sedation and respiratory depression in the infant.
Advice for the public
Most medicines can still be safely used during breastfeeding, provided that those chosen are compatible with breastfeeding or pose a low risk of passing into breast milk in significant amounts.
Mothers are advised to always inform their doctor or pharmacist that they are breastfeeding so that appropriate medicines can be selected.
They should also discuss with a healthcare professional before starting or stopping any medicines.
Use of health supplements and traditional preparations should also be informed to their doctor or pharmacist.
When medicines are necessary, mothers may consider feeding the infant just before taking the medicine to minimise the amount of drug transferred into breast milk.
For short-term use of medicines that may pose a risk to the infant, mothers may consider expressing breast milk before starting the treatment to maintain milk supply, and discarding the milk expressed while they are taking the medicine.
Breastfeeding should only be resumed after allowing sufficient time for the medicine to be fully eliminated from the body.
For mothers who require long-term treatment with medicines that pass into breast milk and may harm the infant, replacing breastfeeding with infant formula may be considered.
This decision should be discussed with a doctor or pharmacist, including guidance on weaning and selecting an appropriate formula for the infant.
Nevertheless, careful monitoring of the infant is important when mothers are taking any medicines.
Mothers are advised to observe their babies for any possible side effects, such as excessive sleepiness, unusual fussiness or irritability, changes in sleeping or feeding patterns, diarrhoea, skin rashes, breathing difficulties, or the infant appearing limp or floppy after feeding.
If any of these signs are observed, mothers should seek medical attention promptly.
As a conclusion, breastfeeding remains the best option for infant nutrition, and most medicines can be used safely during breastfeeding when appropriately selected.
The use of medicines during lactation requires a careful balance between effective treatment for mother and safety for baby, with each medicine assessed on an individual basis.
Hor Cheah Yen is a pharmacist at Hospital Seri Manjung, Perak. This article is courtesy of the Health Ministry’s Pharmacy Practice and Development Division. For more information, email starhealth@thestar.com.my. The information provided is for educational and communication purposes only, and should not be considered as medical advice. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this article. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
