Cough and Allergy Medications During Lactation: Safe Choices to Avoid Infant Sedation

When you're breastfeeding and hit with a bad cold or seasonal allergies, the last thing you want is to choose between feeling better and keeping your baby safe. But many common cough and allergy meds carry hidden risks-especially when it comes to infant sedation. The truth is, not all medications are created equal when they pass into breast milk. Some are harmless. Others can make your baby dangerously sleepy, slow their breathing, or even stop them from feeding properly.

Why Some Medications Are Risky for Nursing Babies

Your baby’s body is still learning how to process drugs. Their liver and kidneys aren’t fully developed, especially in the first two months. That means even small amounts of certain medications can build up in their system. Sedating drugs like first-generation antihistamines and codeine are the biggest culprits. These aren’t just "maybe" risks-they’ve been linked to real, documented cases of infant respiratory depression and even death.

Take codeine, for example. Once thought to be safe, it’s now flagged by the FDA with a black box warning. Why? Because some people are "ultra-rapid metabolizers"-about 1 in 100 Caucasians-and their bodies turn codeine into morphine way too fast. That morphine ends up in breast milk. A 2012 study found infants exposed to codeine through breast milk had serum levels as high as 30 ng/mL. For a newborn, that’s enough to shut down breathing. There are reports of 13-day-old babies dying after their mothers took codeine for postpartum pain.

First-Generation Antihistamines: The Silent Sleepers

Diphenhydramine (Benadryl), chlorpheniramine, and hydroxyzine are common in over-the-counter allergy and cold meds. They work well for runny noses and sneezing-but they also cross into breast milk easily. Studies show milk-to-plasma ratios of 0.2 to 1.0, meaning your baby gets a significant dose relative to your weight.

A Motherisk study found 1.6% of nursing infants showed noticeable drowsiness after their moms took diphenhydramine. That might sound low, but when you consider how many moms use it, the numbers add up. Reddit threads and breastfeeding forums are full of stories: "My 6-week-old wouldn’t wake up to feed after one Benadryl," or "She slept for 5 hours straight and missed three feedings." One survey found 68% of mothers who used codeine or diphenhydramine noticed changes in their baby’s alertness. Only 12% saw changes with ibuprofen.

The Royal Women’s Hospital in Australia and the American Academy of Pediatrics both warn: these meds aren’t recommended. Even a single dose can cause issues in newborns. And if you’re using it daily? The risk grows.

The Safer Alternatives: Second-Generation Antihistamines

Good news: you don’t have to suffer through allergies without relief. Second-generation antihistamines like cetirizine (Zyrtec), loratadine (Claritin), and fexofenadine (Allegra) are the new gold standard for breastfeeding moms.

Here’s why they’re safer:

• Cetirizine: Milk-to-plasma ratio of 0.25-0.75. Infant exposure is only about 0.14% of your weight-adjusted dose. No sedation reported in clinical studies.
• Loratadine: Minimal transfer-just 0.04-0.05% of your dose gets into milk. Even better, it’s not sedating for you or your baby.
• Fexofenadine: Almost no transfer into breast milk. Used safely by thousands of nursing mothers.

WebMD, Cleveland Clinic, and the Academy of Breastfeeding Medicine all list these as L1 (safest) category drugs. One mother on BabyCenter wrote: "I’ve taken Zyrtec daily since my baby was 3 months old. He’s 10 months now-never slept more than normal, never missed a feed. No issues."

What About Cough Suppressants?

Dextromethorphan, the active ingredient in most cough syrups like Robitussin DM, is another win. It transfers into breast milk at only 0.1% of your dose. That’s barely measurable. The InfantRisk Center classifies it as L1. It’s not sedating for babies and doesn’t affect feeding or breathing.

But avoid combination products. Many cough syrups contain diphenhydramine or codeine under "extra strength" or "nighttime" labels. Always read the ingredients. If you see "PM," "Night," or "All-in-One," skip it. Stick to plain dextromethorphan-only formulas.

Nasal Sprays and Decongestants: What’s Safe?

For stuffy noses, nasal steroids like fluticasone (Flonase) and budesonide (Rhinocort) are ideal. Less than 0.1% of the dose enters your bloodstream-meaning almost nothing reaches your milk. The AAFP recommends them as first-line treatment for allergic rhinitis during breastfeeding.

Saline nasal sprays are even safer-zero drugs, just salt water. Use them as often as needed. They work great for congestion without any risk.

Now, avoid oral decongestants like pseudoephedrine (Sudafed). They don’t make babies sleepy-but they can tank your milk supply. One 2003 study showed a 24% drop in milk production within 24 hours of a single dose. That’s not worth the trade-off. If you must use it, do it once, at the lowest dose, and monitor your supply closely.

Timing Matters: When to Take Your Meds

Even if you’re taking a safer med, timing can reduce exposure even further. Here’s what experts recommend:

• Take your dose right after you breastfeed-not before.
• If you’re on a 4-6 hour medication like cetirizine, wait 3-4 hours before the next feed.
• Use your baby’s longest sleep stretch (usually overnight) as your dosing window.

Don’t pump and dump unless you’re on something truly dangerous like codeine. Pumping doesn’t speed up drug clearance from your body-it just removes milk you could’ve fed your baby. It also signals your body to make less milk. That’s a double loss.

What to Watch For in Your Baby

Even with "safe" meds, keep an eye out for these signs:

• Excessive sleepiness-you can’t wake your baby for a feed
• Shallow or irregular breathing
• Decreased feeding frequency or weak suck
• Unusual fussiness or lethargy

If you notice any of these, call your pediatrician. Don’t wait. In newborns, even mild sedation can lead to poor weight gain or dehydration.

What’s Changed in the Last 5 Years

The landscape has shifted dramatically. Five years ago, codeine was still listed as "probably safe" in many parenting guides. Now? It’s banned for breastfeeding mothers by the Academy of Breastfeeding Medicine. The LactMed database from the NIH now flags 17 medications with sedation risks-up from just 9 in 2018.

Over-the-counter brands have caught up too. In 2015, only 42% of allergy meds had "non-drowsy" labels. Now, 68% do. You can find loratadine, cetirizine, and fexofenadine in almost every pharmacy aisle. Look for "non-drowsy," "24-hour," or "daytime" on the box.

Real-Life Decisions: What Should You Do?

You’re not alone in this. Every year, 23% of calls to the InfantRisk Center are about sedation risks from medications. Here’s how to make the right call:

• For allergies: Use loratadine or cetirizine daily. Safe, effective, no trade-offs.
• For cough: Use plain dextromethorphan. Skip anything with "PM" or "night."
• For congestion: Try saline spray first. If you need more, use Flonase or Rhinocort.
• Avoid: Codeine, diphenhydramine, hydroxyzine, pseudoephedrine.

If you’re unsure, call the InfantRisk Center or your IBCLC. Don’t guess. There’s no need to suffer-but there’s also no need to risk your baby’s safety.

Final Thought: You’re Not Alone

Breastfeeding while sick is hard. You feel guilty for taking meds. You worry you’re letting your baby down. But choosing the right medicine isn’t selfish-it’s responsible. You’re not just protecting your baby from sedation. You’re protecting your ability to keep feeding them. And that’s the biggest win of all.