Many common medications, even those that are over-the-counter (OTC), aren't safe for babies. Deciphering which medications are safe for newborns can be both confusing and overwhelming. It's helpful to remember that newborns aren't just “little adults.”

Administering some medications can actually cause great harm to babies, since they process and metabolize medications very differently than adults. Fortunately, the Food and Drug Administration oversees and regulates OTC medications in the United States, providing age and weight recommendations for safe dosage.

To help you know what's safe and what's not, here are the top eight types of medications to avoid giving your baby (depending on their age), what to look for instead and how to dose medicine in the safest way.

Medicines to avoid with infants

1. Ibuprofen (Motrin/Advil)

Ibuprofen is an effective antipyretic (fever reducer) and analgesic (pain reliever). While great for fever and teething pain, ibuprofen should be avoided until your baby is at least 6 months old, unless otherwise directed by your doctor. Giving ibuprofen to infants younger than 6 months old can lead to an increase in gastrointestinal side effects like vomiting, diarrhea and abdominal pain as well as kidney impairment/renal failure.

A fever is defined as a rectal temperature of 100.4 degrees Fahrenheit or higher. If your infant is 3–6 months old with a fever, give them acetaminophen (Tylenol) only. And for infants under 3 months old with a fever, do not give ANY meds—just call your doctor right away.

2. Aspirin (acetylsalicylic acid, salicylates)

The use of aspirin in children under 18 years old should be completely avoided, since aspirin (and its derivatives) can increase the risk of Reye’s syndrome, a rare disorder that can cause significant brain swelling and liver damage. The exact mechanism is unknown, but Reye’s syndrome is usually triggered by a viral infection, such as the flu or chickenpox, followed by the use of aspirin.

Many over-the-counter medications contain aspirin, such as Alka Seltzer, Pepto-Bismol and wintergreen oil. Be sure to check the labels so that you don't unknowingly give your infant or child aspirin-containing products.

3. Benzocaine

Benzocaine is the active ingredient found in many teething medications and gels, marketed to parents as providing temporary relief from sore gums due to teething in infants. But since benzocaine hasn't been proven to be totally effective for teething pain and involves serious safety risks, the FDA is actually working to recall this medication for children under 2 years old. Benzocaine can cause a dangerous condition called methemoglobinemia, where the amount of oxygen carried through the blood is greatly reduced. This prevents tissues from receiving oxygen and can lead to cyanosis (blue discoloration in the skin) and even death.

The FDA also cautions against the use of homeopathic teething tablets, like Hyland’s, so always consult with your physician before considering any homeopathic medications.

4. Dextromethorphan and guaifenesin (cough suppressants and expectorants)

These ingredients are found in over-the-counter cough and cold products, including cough syrup and expectorants like Robitussin, NyQuil, Mucinex, Triaminic and Theraflu.

The common cold in babies can give parents high anxiety, but most cold symptoms go away on their own without any medicine. But colds remain one of the top reasons parents bring their children in to see their pediatrician.

It's important to know that the FDA doesn't recommend any over-the-counter medicines for cough or cold symptoms in children younger than 2 years old. These include expectorants (for loosening mucus so that it can be coughed up) and antitussives (cough suppressants). The label may also include “nasal decongestants” and “antihistamines”—both of which should also be avoided in children under 2 years old.

Manufacturers are now voluntarily relabeling packaging to warn against use in children under 4 years of age. Ingestion of these medications can lead to convulsions, rapid heart rate, decreased levels of consciousness and even death.

Safer alternatives for relieving cold symptoms include a cool mist humidifier and/or nasal suctioning with saline.

5. Antihistamines (allergy medicine)

This type of medication includes diphenhydramine (Benadryl), loratadine (Claritin), cetirizine (Zyrtec) and fexofenadine (Allegra).

Diphenhydramine, better known as Benadryl, should never be given to infants for cough or cold symptoms, for similar reasons as to why we avoid cough syrup and expectorants. Infant ingestion of Benadryl can lead to convulsions, rapid heart rate, trouble breathing and even death. Benadryl can sometimes be used for allergy symptoms in infants, but only under the direct supervision of a physician. And Benadryl should never be administered for off-label uses, such as helping children fall asleep for a big car or plane ride or even getting them to sleep for a normal night.

Other antihistamines, like loratadine (Claritin), cetirizine (Zyrtec), and fexofenadine (Allegra) should also not be used in children younger than 2 years old unless directed by a physician.

6. Pseudoephedrine and phenylephrine (decongestants)

If your baby's sinuses seem stuffed up, you'll need to avoid decongestant medications such as Dimetapp, Sudafed or Mucinex.

Not only does the data show that the use of decongestants in babies is no better than a placebo, but these medications cause blood vessels to constrict and can lead to convulsions, a rapid heart rate and even death. These medicines should be avoided in all babies under the age of two years old, and quite frankly, shouldn't be given to any child under 12 years old.

So what to do about that stuffy nose? Usually, the culprit is the common cold, which almost always goes away on its own. But there are a variety of home remedies that have proven to be more effective than any decongestant, including proper nasal suctioning with saline, a cool mist humidifier and steam inhalation (such as from a hot shower)—just be sure not to let hot steam touch baby's skin directly, since it can cause burns. Instead, try turning on a hot shower, then staying in the bathroom (outside of the shower) with baby with the door and window closed and fan off. Let the entire bathroom fill with steam and hang out in there with baby for about 10–15 minutes.

7. Bismuth or loperamide (Pepto-Bismol and Immodium)

While diarrhea can be alarming (and overwhelmingly messy), it's important to note that it can lead to dehydration in infants. Regardless, babies should never be given any anti-diarrheal medication, since these medications can cause lethargy and intestinal obstruction. Studies have also found that they have no benefits over placebo, even in older children, so should only be used under the close supervision of a physician.

8. Laxatives

Just like with diarrhea, constipation in babies can be distressing. When treating infant constipation, it's important to avoid all of the following: mineral oil (risks of aspiration), stimulant laxatives such as Senna and Bisacodyl (dehydration, electrolyte imbalances), Fleets ememas (electrolyte imbalances), milk/molasses/lactulose enemas (abdominal distension) and phosphate enemas (electrolyte imbalances, kidney damage).

Instead, try adding a small amount of water or apple or pear juice to feedings (for infants one month or older), adding fiber-rich food if baby is eating solids, massaging baby's tummy or doing bicycle motion with baby's legs.

Tips for giving medication to babies

Dose carefully, using the package-included dropper or measuring device only.
Dosing based on the child's weight, rather than age, is always recommended, since baby sizes vary. Be sure to know your baby’s most recent weight.
Always use infant formulations. Don’t be tempted to give baby “smaller doses” of adult medication.
Check expiration dates. Expired meds can lose potency over time or chemically break down into dangerous compounds. Dispose of expired medications properly. Often, your local police department will have a drug collection program, as do some pharmacies.

As a safe rule, always consult your doctor before giving any infant medication, even if it's easily accessible in the drug store aisle. With all of the things to remember as a new parent, discerning which medications to take or avoid shouldn't be one of them. Don't hesitate to ask, your doctors are here for you.

Disclaimer: The medical information provided does not substitute for medical advice and is for educational purposes only.

Factually reviewed by Dr. Seran Kim, board-certified Emergency Physician, on June 7, 2021.