Phenergan Drug Warning in Children

When a child is sick and vomiting, parents and pediatricians both want to reach for a medication that can help them keep down food and, especially, fluids. Dehydration is a serious risk of vomiting.

The drug Phenergan (promethazine) stops vomiting and has been around for a long time, but it could be dangerous for children, especially if they're under age 2. In fact, it even carries a black-box warning, the most serious type of warning put out by the Food and Drug Administration (FDA).

This article covers the possible side effects that can come with taking Phenergan or giving Phenergan to your child. It includes Phenergan dosage information along with alternatives to Phenergan you may consider to stop vomiting and prevent dehydration.

Mother trying to give son medication
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Phenergan for Vomiting

Phenergan is an antiemetic drug used for vomiting. It's also used as an antihistamine (allergy pill) and a sedative (sleeping pill). It's available as tablets, suppositories, injectables, or syrups.

Phenergan should never be used in children less than 2 years of age. You and your pediatrician should consider alternatives in children over age 2, as well, due to the risk of dangerous side effects.

How Much Phenergan Can You Take?

Phenergan tablets and suppositories contain either 12.5 mg, 25 mg, or 50 mg of the active ingredient promethazine. For nausea and vomiting in children older than 2 years of age, the recommended dose is 0.5 milligrams (mg) of promethazine per pound of body weight. A typical dose is 25 mg taken every four to six hours as needed.

Side Effects and Warnings

Two major warnings are associated with the use of Phenergan.

One warning is about the risk of respiratory depression (hypoventilation), which can cause slow heart rate, shortness of breath, coma, and death unless promptly treated. The warning was issued after several children stopped breathing or went into cardiac arrest after taking the drug.

The FDA in 2005 added a boxed warning to Phenergan stating that the drug is contraindicated (should absolutely not be used) in children under the age of 2 and should be used cautiously in children over the age of 2.

Other side effects experienced by children on Phenergan include:

  • Agitation
  • Hallucinations
  • Seizures
  • Dystonic reactions in children (muscle spasms or contractions causing involuntary movements)

These side effects occurred at a wide variety of doses.

Even if your child does not have serious respiratory depression, drowsiness related to the medication can interfere with treatment of vomiting. If your child is sleeping, he isn't drinking fluids and can become even more dehydrated.

In 2009, another warning was given for the use of Phenergan. It said that injections of the drug were associated with severe tissue injury, sometimes giving rise to gangrene or necrosis (tissue death), requiring amputation.

Alternatives To Phenergan

Fortunately, when it comes to a vomiting child, you have a lot of alternatives that appear to be much safer. These include both things you can do yourself at home and different medications.

Home Remedies

Home measures can be very helpful and are recommended by the World Health Organization.

With mild dehydration, your child may act thirsty and have a dry mouth. The first thing to try is oral rehydration solutions that restore fluids and replace lost electrolytes. You can buy products such as Enfalyte, Pedialyte, or Gatorade, or you can make your own rehydration solution from ingredients in your kitchen.

Not only are homemade solutions just as effective as store-bought options, but they're much cheaper and allow you to avoid the food dyes present in many from the store.

One of the biggest mistakes in encouraging your child to drink fluids is to give them too much too fast. It's hard not to give them all they want, especially if they're complaining about thirst, but going slow will help the fluids "stay down."

Treating Moderate or Severe Dehydration

With moderate or severe dehydration, you may notice fewer wet diapers, sunken eyes, a lack of tears when the child cries, and listlessness. These are serious signs and you should get medical attention right away.

For vomiting, it's recommended that you begin by providing 1 teaspoon up to 1 tablespoon (3 teaspoons) of an oral electrolyte solution every five to 10 minutes.

The total amount of fluid your child will need depends on their degree of dehydration and can be estimated with a simple formula.

As your child's nausea improves, and especially if they have diarrhea, you may wish to slowly introduce foods back into their diet. You can give foods like bread, potatoes, or rice along with lean meat, yogurt, fruits, and vegetables. Avoid foods high in fat as they are harder to digest.

If your child also has diarrhea, the BRAT diet (bananas, rice, applesauce, toast) may help firm the stool, but it doesn't have enough nutrients to be used for an extended time. (The American Academy of Pediatrics no longer recommends this diet and favors oral hydration.)


If an antiemetic medication is necessary, there are now many alternatives.

One of the most commonly used alternative medications for children is Zofran (ondansetron). Zofran is approved for the treatment of chemotherapy-induced nausea and vomiting but is often used "off-label" for treating the "stomach flu," medically known as acute gastroenteritis in children.

When used for children with stomach flu, Zofran has been found to reduce the chance that a child will need intravenous fluids (which requires hospitalization). Zofran can be used even in younger children for whom Phenergan is not recommended.

Zofran comes with a warning as well—the injectable form can change the electrical activity of the heart, which can increase the risk of a potentially fatal heart rhythm. However, that only happens with the much higher doses required for chemotherapy, not the doses used for stomach flu.

This medication can also be quite expensive, as well.

When Should You Call Your Healthcare Provider?

It's important to call your healthcare provider if you are concerned about your child's vomiting, no matter how mild or severe it appears to be. Trust your gut as a parent. If your child is vomiting and goes without drinking any fluid for more than a few hours, call your healthcare provider.

Call the healthcare provider right away if any of these symptoms occur:

  • Green-tinged or blood-tinged vomit
  • Blood in the vomit or stool
  • Abdominal pain that starts near the navel and spreads to the lower right abdomen

These could be signs of appendicitis, which is a medical emergency.

A Word From Verywell

Learning about the warnings for the use of Phenergan in children is frightening as a parent, but there are plenty of alternatives that do not carry the same risks. The benefit of any medication needs to be weighed against potential risks. If your child is able to tolerate oral rehydration solution and is only mildly dehydrated, these home remedies can be very effective at preventing dehydration until the virus passes.

Frequently Asked Questions

  • Is Phenergen available over the counter?

    Phenergen can potentially cause life-threatening side effects in some people. For this reason, it is not available over the counter. To use Phenergen, you will need a prescription from a healthcare provider.

  • Does Phenergen affect heart rate?

    Both slow heart rate (bradycardia) and rapid heart rate (tachycardia) are possible side effects of Phenergen. Children are more at risk.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U. S. Food and Drug Administration, Access Data. Wyeth Pharmaceuticals, Inc. Phenergan (promethazine HCI) Tablets and Suppositories.

  2. Promethazine warning. JAMA. 2005;293(8):921. doi:10.1001/jama.293.8.921-c

  3. U.S. National Library of Medicine, DailyMed. Label: Phenergan-promethazine hydrochloride injection.

  4. Vega RM, Avva U. Pediatric dehydration. StatPearls.

  5. Churgay CA, Aftab Z. Gastroenteritis in children: Part II. Prevention and management. Am Fam Physician. 2012;85(11):1066–1070. 

  6. Fedorowicz Z, Jagannath VA, Carter B. Antiemetics for reducing vomiting related to acute gastroenteritis in children and adolescents. Cochrane Database of Systematic Reviews. doi:10.1002/14651858.cd005506.pub5

  7. U.S. Food and Drug Administration. FDA Drug Safety Communication: New information regarding QT prolongation with ondansetron (Zofran).

  8. Stanford Children's Health, Lucile Packard Children's Hospital. Could that stomachache in your child be appendicitis?

Additional Reading

By Vincent Iannelli, MD
 Vincent Iannelli, MD, is a board-certified pediatrician and fellow of the American Academy of Pediatrics. Dr. Iannelli has cared for children for more than 20 years.