An in-depth look at how various prescription and illegal drugs can impact breastfeeding mothers and their babies, including risks, signs of exposure, and safety tips.

Breastfeeding provides ideal nutrition and passive immunity for growing infants. However, looking up drug side effects shows that many medications and illegal drugs can transfer to breast milk, potentially harming the nursing baby. 

As a breastfeeding mother, it’s crucial to understand how your choices affect your milk supply and your baby’s health.

As a new mom struggling with severe insomnia, I desperately wanted something to help me sleep but was hesitant to take anything while breastfeeding my 2-month-old. I decided to look up drug side effects for sleep aids and was shocked to learn the potential risks. 

This experience taught me the importance of fully researching any medication before using it while nursing.

How Drugs Transfer to Breastmilk

Most drugs taken by the mother can transfer to her breastmilk to some degree. The amount that transfers depends on factors like:

• The mother’s dosage/frequency of the drug
• How much time has passed since taking the drug
• The drug’s molecular weight – smaller molecules pass easier

For example, cold medicines like pseudoephedrine have a low molecular weight and can readily pass into breast milk. Heavy pain medications like morphine have a higher molecular weight and small amounts may transfer.

Illicit drugs also transfer based on molecular size. For instance, cocaine, amphetamines, and marijuana components can easily enter milk. Heroin has a higher molecular weight, so less passes through, but still poses risks.

Potential Effects on the Nursing Baby

The effects on a breastfed baby depend on the drug itself, the amount transferred, and the infant’s age. Possible effects include:

• Drowsiness, difficulty feeding, and slowed development (from sedatives or pain medications)
• Irritability, gastrointestinal issues, and interrupted sleep (from stimulants)
• Slowed motor development and respiratory issues (from marijuana)
• Withdrawal symptoms in babies of addicted mothers

In my case, the sleep aids recommended by my doctor were contraindicated during breastfeeding because of potential sedative effects. This could have impacted my baby’s feeding and development.

Signs of Drug Exposure in a Nursing Baby

Watch for these possible signs of drug exposure in a breastfed infant:

• Excess sleepiness and lethargy
• Poor feeding and sucking reflex
• Shallow or erratic breathing
• Low muscle tone
• Irritability, tremors, or seizures

For example, my sister’s baby was extremely fussy and refused to nurse after she took a cough medicine. She realized the medication was likely the cause.

If you notice any concerning symptoms in your breastfed baby, contact their pediatrician immediately. Be open about any drugs you’re taking to help identify the cause.

Tips for Safety While Breastfeeding

If you require medication while nursing, look up drug side effects and discuss risks/alternatives with your doctor. Some general tips include:

• Take the lowest effective dosage possible
• Time feedings before/after taking the drug to minimize exposure
• Avoid breastfeeding for 4+ hours after using recreational drugs or alcohol
• Never mix drugs with breastfeeding without medical guidance
• Seek professional help if struggling with substance abuse