What goes into the decision

Clinicians considering a medicine during breastfeeding weigh several factors, and understanding them makes the conversation more productive.

  • How much of the drug reaches milk. This varies widely between medicines based on their chemical properties.
  • How much the infant would absorb. Some substances are poorly absorbed from an infant's gut.
  • The infant's age and maturity. A newborn, particularly a premature one, handles substances very differently from an older infant with mature liver and kidney function. This is one of the most important variables and one people rarely think of.
  • Whether effects have been reported in nursing infants. LactMed collects this.
  • The parent's need for the medicine. An untreated condition affects caregiving too.
  • Available alternatives.
  • The value of breastfeeding to this particular family, which is not a clinical variable a website can weigh.

That final point matters. Stopping breastfeeding is not a neutral default option — it has its own consequences, practical and personal, and treating it as the automatically cautious choice is a mistake.

LactMed, and how to use it

LactMed, the Drugs and Lactation Database, is a National Institutes of Health resource summarising available information about individual medicines in breastfeeding. It covers measured drug levels in milk and infant blood where those exist, effects reported in nursing infants, effects on lactation itself, and alternative agents to consider.

It is written for clinicians but is publicly readable and free. Its main value to a patient is as something to bring to a conversation rather than as a source of a personal conclusion.

We deliberately do not reproduce or summarise LactMed entries for specific drugs on this site. Doing so responsibly requires reading the entry in full, in its current version, and appraising it — and a partial summary of a lactation record is exactly the kind of content that leads people to wrong conclusions about their own situation.

Search the database for the specific medicine, read the entry, and take your questions to your prescriber, pharmacist, or a MotherToBaby specialist.

The caregiving question

Discussions about medicines and breastfeeding focus almost entirely on what reaches the infant through milk. There is a second question that gets far less attention and matters a great deal.

Caring for an infant while sedated carries its own risks. A sedating medicine affects alertness, reaction time and the depth of sleep — and infant care involves night waking, carrying a baby on stairs, and responding quickly to a child who has moved unexpectedly.

Safe sleep guidance already advises against bed-sharing in a number of circumstances, and being under the influence of a sedating medicine is specifically among the situations where the risk of bed-sharing is increased.

This is worth raising explicitly with your clinician. Practical questions include timing of doses relative to night feeds, whether another adult can be responsible during periods of sedation, and what sleep arrangements are appropriate. These conversations are not about judgement; they are about arranging things so that the medicine and the caregiving can coexist safely.

What to watch for and who to tell

If a clinician has advised that continuing a medicine while breastfeeding is appropriate, they may ask you to watch the infant for particular things. In general terms, changes worth reporting to a paediatrician include unusual sleepiness, difficulty waking for feeds, poor feeding, unusual irritability, or any change from the baby's established pattern.

Tell the infant's paediatrician what you are taking. They are looking after the baby, and a complete picture helps them interpret anything they observe. Parents frequently assume this is only relevant if the baby is having a problem, and it is more useful shared in advance.

Where to get individualised advice

  • MotherToBaby. Free, individualised counselling about exposures during pregnancy and breastfeeding, by phone, text, chat and email.
  • Your prescriber. Can weigh your need for the medicine against alternatives.
  • The infant's paediatrician. Can advise on what to watch for.
  • A lactation consultant. Particularly useful for the practical side, including timing of feeds.
  • Your pharmacist. Available without an appointment and able to check your complete list.
  • LactMed. The reference to read and bring with you.