What Drugs Affect Breast Milk?

Many different drugs affect breast milk.

Both illegal drugs and legal substances potentially enter the breast milk through passive diffusion. Whether or not something enters the breast milk depends on many factors, including molecular weights and lipid solubility. While these are big doctor words that you shouldn’t necessarily worry about, this is one of the ways that we can decide between different types of drug therapy in a lactating woman.

New mothers worry about so many different things. Keeping your baby safe from potential drug exposure through your breast milk is one of those concerns.

In this article, we will look at common substances and drugs that women potentially use during breast feeding that can affect their infants.

Caffeine

Caffeine is a natural stimulant commonly found in beverages such as coffee, tea, and energy drinks. While addiction to caffeine is possible, it is not classified as a drug of abuse. As someone who misses their regular cup of morning coffee knows, there are noticeable withdrawal effects when abruptly stopping regular caffeine consumption.

Breastfeeding mothers can definitely continue to consume caffeine while breastfeeding, just in moderation. Studies show that moderate levels of caffeine consumption (approximately 300 mg per day) do not have adverse effects on the baby. This amount of caffeine is approximately equivalent to drinking three cups of coffee per day.

However, excessive caffeine can transfer to human breast milk and affect a baby’s sleep patterns negatively. Additionally, it can cause increased irritability or fussiness in the infant due to its stimulating properties.

Sometimes, even if you consume caffeine within the recommended limits, some babies are highly sensitive to its effects. If you observe that your breastfeeding infant becomes more irritable after your morning coffee, try reducing your caffeine intake.

Tobacco

Smoking tobacco is harmful to all humans, especially babies. This is evidenced by studies that smoking increases the risk of sudden infant death syndrome.

Not only are breastfed babies sensitive to smoke exposure, but smoking also potentially reduces a breastfeeding mother’s milk supply. Additionally, Infant exposure to smoking can result in increased respiratory infections, a higher risk for developing asthma, and more ear infections. Although breastfeeding can help mitigate some of these consequences, it does not eliminate all of them.

In addition to the exposure to the carcinogens in smoke itself, nicotine in the cigarettes is also harmful to babies. Nicotine can be found in high concentrations in human milk for breastfeeding mothers who smoke or use nicotine products. The infant dose of nicotine is highest right after the nursing mother smokes or consumes nicotine.

As a breastfeeding expert, I would prefer that you breastfeed your baby above all else. If you continue to smoke or use nicotine as a breastfeeding mother, there are safer ways to limit your baby’s drug exposure.

• Feed your baby before you smoke or use nicotine
• Don’t smoke in indoor or enclosed spaces where baby spends time
• Change your clothes and wash your hands after smoking before touching the baby again

What About E-Cigarettes?

Unfortunately, E-cigarettes are not safer than regular cigarettes for breastfeeding mothers. They still contain chemicals that harm infants and thus are not a safer way to quit smoking.

Alternative ways to quit smoking:

• Nicotine patch, lozenges, or gum
• Cognitive behavioral therapy

Alcohol

During the neonatal period and beyond, it is okay for a breastfeeding mother to consume an occasional alcoholic beverage without causing harm to her baby. Alcohol moves in and out of the breast milk in conjunction with its movement in and out of your blood. Maternal plasma concentrations of alcohol are similar to breast milk concentrations. In other words, your blood alcohol level and your breast milk alcohol level are similar.

Just like other drugs, alcohol transfers into breast milk via passive diffusion.

However, it is important to know that heavy use of alcohol can impact breast milk production. Over time, alcohol has a negative effect on prolactin levels and therefore decreases milk production.

If you keep moderation in mind, it is safest to breastfeed your baby first before you enjoy a glass of wine. After the effects of alcohol have subsided, it is usually safe to breastfeed again with minimal alcohol exposure to the infant. (typically 2 hours after finishing your drink).

Just as a reminder, a standard drink is:

• 12 ounces of beer
• 5 ounces of wine
• 1.5 ounces of 80 proof spirits

Marijuana

As marijuana is becoming legal in more states, its popularity is increasing for both recreational and medicinal use.

Occasional use of marijuana while breastfeeding is likely not harmful. However, you need to be aware of the effects of THC, which is the psychoactive component of marijuana. This drug has a tendency to concentrate in fatty tissues due to its lipid solubility. A baby’s brain has a high concentration of fatty tissue.  As a result, adverse effects on the baby are drowsiness and poor sucking.

Currently, evidence is incomplete and we do not know what the long term side effects could be on a baby’s growth and development after chronic exposure to THC.

Another consideration is that marijuana is often used as a form of self-medication for various chronic conditions. Pregnant and breastfeeding mothers may use marijuana for pain, nausea and/or depression and anxiety. While prescription drugs used to treat these conditions have drawbacks, most health care providers recommend against the use of this illegal drug for these uses in this population due to the unknown long-term effects on the baby.

Opiates

Pain is one of the vital signs that most health care providers measure at medical visits. It deserves treatment. Unfortunately while opiates are effective at treating this pain, they are also highly addictive. They bind to receptors in the brain, causing a dissociative effect. In addition, these medications can also produce a pleasurable sensation that is addictive.

As the opiate crises rages on, health professionals are taking measures to decrease prescriptions for these medications. We are required by our licensing boards to consider other treatments for pain besides these addictive medications.

We also know that regular opiate use during pregnancy often leads to an opiate addicted newborn. The transfer of drugs through the placenta consistently exposes the fetus to the medication. After the delivery, these infants face the risk of opiate withdrawal. Opiate addicted newborns are treated with supportive care as well as medications.

In addition, women who are in opiate addiction treatment programs are often prescribed a medication such as methadone or buprenorphine. These medications pass through the breast milk, but ideally the baby weans off the medication as the mother’s dose is lowered. Health professionals like me recommend that postpartum women who are in opiate addiction recovery breastfeed their babies for this reason.

Short term use of opiate medications can be safe for breastfeeding mothers, but alternative drugs and treatments should be prioritized when possible.

Other Illicit Drugs

Breastfeeding mothers need to avoid the use of illicit drugs such as cocaine, heroin, and other drugs of abuse. Breastfed infants receive high doses of these drugs through breast milk and their potential effects on the baby are detrimental.

These drugs cause symptoms such as poor weight gain, jitteriness, difficulty sleeping, irritability, and feeding problems. Additionally, the theoretical risk of long term symptoms is also high.

Additionally, mothers who are under the influence of a substance may not be able to provide safe care for their babies. This is another way for potential harm from both the drugs and possible instances of abuse or neglect.

Both pregnant women and breastfeeding women can receive assistance for their drug addiction by contacting the SAMHSA National Helpline at 1-800-662-4357. This helpline offers free and confidential support.

For continued reading on this topic, click on medications and breastfeeding: what is safe? to read more about medications and the effects effects of drugs on breastfeeding babies.

© 127 Pediatrics, March 2024

This article is for information only, please do not interpret this as medical advice. See care from your personal physician.