This medication description is not meant for treatment prescription without the intervention of a specialist.

Common Uses

Promethazine is a first-generation H1 receptor antagonist antihistamine and antiemetic medication. It is used for relieving allergy symptoms, including hives and nasal congestion. Also Promethazine is used to prevent and control pain and nausea during and after surgery, and to help produce light sleep, and for the prevention of motion sickness. Promethazine is not to be used to treat asthma. It may also be used for other conditions as determined by your doctor.

How to Take

Allergy.

Adults: The average oral dose is 25 milligrams taken before bed; however, your doctor may have you take 12.5 milligrams before meals and before bed. Children: The usual dose is a single 25-milligram dose at bedtime, or 6.25 to 12.5 milligrams 3 times daily.

Motion sickness.

Adults: The average adult dose is 25 milligrams taken twice daily. The first dose should be taken one-half to 1 hour before you plan to travel, and the second dose 8 to 12 hours later, if necessary. On travel days after that, the recommended dose is 25 milligrams when you get up and again before the evening meal. Children: The usual dose of Promethazine tablets, syrup, or rectal suppositories is 12.5 to 25 milligrams taken twice a day.

Nausea and vomiting.

The average dose of Promethazine for nausea and vomiting in children or adults is 25 milligrams. When oral medication cannot be tolerated, use the rectal suppository. Your doctor may have you take 12.5 to 25 milligrams every 4 to 6 hours, if necessary.

For nausea and vomiting in children, the dose is usually calculated at 0.5 milligram per pound of body weight and will also be based on the age of the child and the severity of the condition being treated. Promethazine and other anti-vomiting drugs should not be given to children if the cause of the problem is unknown.

Warning and Precautions

Promethazine should not be given to a child younger than 2 years old. Promethazine oral can cause severe breathing problems or death in a child younger than 2. Carefully follow your doctor's instructions when giving this medicine to a child of any age. Do not use Promethazine if you have asthma or other lung disease.

Promethazine can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert. Avoid drinking alcohol, which can increase some of the side effects of Promethazine. Cold or allergy medicine, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for seizures, depression or anxiety can add to sleepiness caused by Promethazine. Tell your doctor if you regularly use any of these medicines, or any other antihistamine.

Promethazine tablets and suppositories are not recommended for children under 2 years of age.

Missed Dose

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

Overdose

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms include severe drowsiness, dizziness, dry mouth, large pupils, flushing, nausea, vomiting, shallow breathing, and fainting.

Storage

Tablets should be stored at room temperature, away from light. Suppositories should be stored in the refrigerator, in a tightly closed container.

Possible Side Effects

Common side effects may include: blurred vision, dizziness, drowsiness, dry mouth, increased or decreased blood pressure, nausea, rash, sedation, vomiting.

More Information

The information given above is a summary. Your pharmacist can provide more information about Promethazine. Do not share this medicine with others for whom it was not prescribed. Do not use this medicine for other health conditions. If using this medicine for an extended period of time, obtain refills before your supply runs out.