Coughing while breastfeeding often raises concerns about the safety of over-the-counter medications for the infant. It is understandable to be cautious, as a mother’s bloodstream is the source of compounds that eventually reach breast milk. While most medications transfer into milk, the amount the baby receives is usually very small. The risk varies widely depending on the specific drug. Making an informed decision requires understanding how drugs move into milk and consulting with a healthcare provider to weigh the benefits against any potential risk.
Understanding Drug Transfer into Breast Milk
Medications enter the mother’s bloodstream, where the process of drug transfer to milk begins. Lactocytes, the cells that produce milk, are surrounded by capillaries carrying the mother’s blood plasma. Drugs generally pass from the plasma into the milk compartment primarily through passive diffusion.
Several factors influence how easily a drug transfers into breast milk. Drugs with small molecular weight, high fat solubility, and low plasma protein binding are more likely to pass into the milk in higher concentrations. However, even when a drug transfers, the dose the baby receives, known as the relative infant dose, is usually a small fraction of the mother’s weight-adjusted dose. Infant age is also a consideration, as newborns and premature infants eliminate drugs more slowly because their liver and kidney functions are immature.
Specific Cough Medicine Ingredients to Avoid
Ingredients commonly found in cough and cold preparations pose a higher risk and should generally be avoided while breastfeeding. Codeine, an opioid cough suppressant, is concerning because it is metabolized into morphine by the CYP2D6 liver enzyme. Mothers who are ultra-rapid metabolizers of this enzyme can produce dangerously high levels of morphine, which can lead to severe infant sedation, breathing difficulties, and even death.
High-dose decongestants, particularly pseudoephedrine, are not recommended for nursing mothers. While the amount of pseudoephedrine passing into breast milk is low and unlikely to harm the infant directly, it can significantly decrease the mother’s milk supply. Studies have shown a single 60 mg dose of pseudoephedrine can reduce milk production by an average of 24% over 24 hours.
First-generation antihistamines, such as diphenhydramine, are sometimes included in cough syrups for their sedating effect. These drugs pass into breast milk in small amounts and may cause drowsiness, lethargy, or changes in sleep patterns in the baby. The risk is higher with large or prolonged doses, or when combined with other sedating agents. Liquid cough formulations containing a high percentage of alcohol should also be avoided, as alcohol passes into breast milk and can accumulate in the infant, who processes it slowly.
Generally Safe Over-the-Counter Options
When treating a cough, focusing on single-ingredient products with well-studied safety profiles is the preferred approach. Dextromethorphan, a common cough suppressant, is considered low-risk during lactation. The amounts of the drug and its active metabolite that pass into breast milk are very low, meaning side effects in the nursing infant are not expected.
Guaifenesin, an expectorant used to thin mucus, is considered compatible with breastfeeding. The drug enters breast milk in minimal amounts, and at typical maternal doses, it is unlikely to cause harm to a nursing infant, especially if the baby is over two months old. Choosing an alcohol-free formulation is always advisable to eliminate the risk associated with that specific component.
For accompanying symptoms like fever or sore throat, analgesics such as acetaminophen or ibuprofen are considered safe options. These pain relievers are well-studied and pass into breast milk in very small quantities that are not expected to cause adverse effects in the infant. When selecting products, check the label carefully to avoid unnecessary combination ingredients that carry a higher risk.
Practical Strategies for Minimizing Infant Exposure
Mothers can take proactive steps to reduce the amount of medication their baby receives through breast milk, even when using generally safe drugs. Timing the dose strategically can help, as most medications reach their peak concentration in breast milk about one to two hours after ingestion. Taking a short-acting medication immediately after a long feeding session, or right before the baby’s longest sleep period, allows the drug levels to drop before the next feeding.
While taking medication, monitor the infant closely for any changes in behavior or well-being. Parents should watch for signs such as increased sleepiness or lethargy, difficulty feeding, unusual irritability, or breathing changes. If any of these symptoms appear, the mother should contact the baby’s healthcare provider immediately.
In many cases, non-pharmacological methods can provide sufficient relief and should be considered as the first line of defense against a cough. These strategies include:
- Maintaining good hydration to thin mucus.
- Using a cool-mist humidifier to soothe irritated airways.
- Applying saline nasal sprays to alleviate congestion.
- Giving a small amount of honey for cough suppression (for babies older than one year).