Promethazine for Kids: Uses, Dosages, Warnings

Phenergan (promethazine) is an antiemetic (a medication that helps stop vomiting). Healthcare providers may prescribe promethazine for kids when they are unable to keep fluids down and are at risk for dehydration.

Promethazine is approved for use in children over the age of 2 but carries a boxed warning that it may cause death in children and can slow or stop breathing. The medication can also cause serious side effects and hallucinations.

This article discusses promethazine for kids and adults. It explains the side effects of promethazine and dosing information. It also offers alternatives to promethazine to help stop vomiting and prevent dehydration.

Warning on Using Promethazine for Kids

Promethazine use in children comes with a few boxed warnings from the U.S. Food and Drug Administration (FDA):

• Promethazine may cause breathing to slow or stop and may cause death in children.
• It should not be given to babies or children who are younger than 2 years old and should be given with caution to children who are 2 years of age or older.
• Combination products containing promethazine and codeine should not be given to children younger than 16 years old.

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

Promethazine injections are also associated with severe tissue injury, that may give rise to gangrene or necrosis (tissue death), requiring amputation.

Promethazine to Treat Vomiting

Promethazine 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.

Dosage

Promethazine can be given as an oral tablet, liquid medication, suppository, or injection. Dosing is based on body weight. It comes in 12.5 milligrams (mg), 25 mg, or 50 mg tablets.

In children older than 2 years of age, the recommended dose is 0.5 mg of promethazine per pound of body weight. A typical dose is 25 mg taken every four to six hours as needed.

Side Effects

Side effects of promethazine in kids 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.

Alternatives to Promethazine 

Fortunately, when it comes to a vomiting child, you have a lot of alternatives that appear to be much safer than promethazine. 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."

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.

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.)

Medications

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 to Call a Healthcare Provider

Promethazine can lead to serious side effects. Contact a healthcare provider right away for any of the following:

• Breathing difficulties, including slowed or paused breathing and wheezing
• Decreased alertness, confusion, or fainting
• Difficulty swallowing
• Fast or irregular pulse or heartbeat
  
• Muscle spasms
• Seizures

Seek emergency medical treatment for any of the following:

• 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.

Summary

Promethazine is helpful for preventing severe dehydration from vomiting. However, it can also cause serious side effects and should be used with caution in children. It can lead to respiratory failure and death, should not be given to children under the age of 2, and should not be taken with opioids in children under age 16.

If your child is vomiting and at risk of dehydration, another antiemetic Zofran is considered a safer alternative to promethazine. Talk to your child's healthcare provider about any concerns you have with this or any other medications.