What is Phenergan: Uses, Warnings & Interactions

Updated May 14, 2025  •  Published Dec 30, 2020

Phenergan overview

BRAND NAMES:

  • Phenergan, Promacot, PremierPro Rx Promethazine, Phenergan, Phenadoz, Phenergan, Promethegan

Generic Names:

  • Promethazine Hcl

Uses:

  • Treats allergies and motion sickness. Also used before and after surgery and other procedures as a sedative and to control pain or nausea and vomiting. This medicine is a phenothiazine., Treats allergies and motion sickness. Also used before and after surgery and other procedures as a sedative and to control pain or nausea and vomiting. This medicine is a phenothiazine., Treats allergies and motion sickness. Also used before and after surgery and other procedures as a sedative and to control pain or nausea and vomiting. This medicine is a phenothiazine.

Therapeutic Classes:

  • Antivertigo, Gastrointestinal Agent, Antiemetic, Antiemetic, Antivertigo, Gastrointestinal Agent, Antiemetic, Antivertigo, Gastrointestinal Agent

Forms:

  • Suppository, Injectable, Tablet, Liquid

How it’s taken:

  • By mouth, By injection, Into the rectum

What is Phenergan used for?

Phenergan is an antihistamine used to treat patients with allergic rhinitis, nausea and vomiting. It is also used to treat motion sickness. This medication may also be used as a sleeping aid. Phenergan lowers the level of histamine in the body. It is indicated for use by patients 2 years and older. This medication is available as an injection.

What form(s) does Phenergan come in

  • Suppository

  • Injectable

  • Tablet

  • Liquid

What are common Phenergan doses?

  • Vial 1ML of 25MG/ML

  • Ampule 1ML of 25MG/ML

Common Phenergan prescriptions

  • Phenergan
    1ml of 50mg/ml ampule

  • Phenergan
    12.5mg suppository

  • Phenergan
    25mg suppository

  • Phenergan
    50mg suppository

  • Phenergan
    1ml of 25mg/ml vial

How to take Phenergan

  • Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Do not freeze the oral liquid.

  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

  • Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.

  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Do not freeze the oral liquid.

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Your doctor will prescribe your exact dose and tell you how often it should be given. This medicine is given as a shot into a muscle or into a vein.

  • Injection routeA nurse or other health provider will give you this medicine.

  • You may be given a few doses of this medicine until your condition improves, and then you will switch to an oral medicine that works the same way. If you have any concerns about this, talk to your doctor.

  • Injection routeA nurse or other health provider will give you this medicine.

  • You may be given a few doses of this medicine until your condition improves, and then you will switch to an oral medicine that works the same way. If you have any concerns about this, talk to your doctor.

  • Your doctor will prescribe your exact dose and tell you how often it should be given. This medicine is given as a shot into a muscle or into a vein.

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Rectal routeWash your hands with soap and water before and after using this medicine. Remove the foil or wrapper from the suppository before inserting it.

  • Rectal routeLie on your left side with your left leg straight or slightly bent, and your right knee bent upward. Gently push the pointed end of the suppository into the rectum about 1 inch.

  • Rectal routeKeep lying down for about 15 minutes to keep the suppository from coming out before it melts. Then, wash your hands again.

  • Rectal routeTo make the suppository easier to insert, you may use a lubricating gel such as K-Y® Jelly, but do not use petroleum jelly (Vaseline®).

  • Rectal routeNever take rectal suppositories by mouth.

  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

  • Rectal routeYou may store the suppositories in the refrigerator, but do not freeze them.

  • Rectal routeKeep lying down for about 15 minutes to keep the suppository from coming out before it melts. Then, wash your hands again.

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

  • Rectal routeLie on your left side with your left leg straight or slightly bent, and your right knee bent upward. Gently push the pointed end of the suppository into the rectum about 1 inch.

  • Rectal routeNever take rectal suppositories by mouth.

  • Rectal routeYou may store the suppositories in the refrigerator, but do not freeze them.

  • Rectal routeTo make the suppository easier to insert, you may use a lubricating gel such as K-Y® Jelly, but do not use petroleum jelly (Vaseline®).

  • Rectal routeWash your hands with soap and water before and after using this medicine. Remove the foil or wrapper from the suppository before inserting it.

What to do if you miss a dose of Phenergan

Phenergan contraindications

  • This medicine is not right for everyone. Do not use it if you had an allergic reaction to promethazine or another phenothiazine medicine, or while you are having asthma symptoms or similar breathing problems.

  • This medicine is not right for everyone. You should not receive it if you had an allergic reaction to promethazine or another phenothiazine medicine.

  • This medicine is not right for everyone. Do not use it if you had an allergic reaction to promethazine or another phenothiazine medicine, or while you are having asthma symptoms or similar breathing problems.

Phenergan warnings

  • Tell your doctor if you are pregnant or breastfeeding, or if you have liver disease, heart or blood vessel disease, glaucoma, a stomach ulcer, bowel problems, an enlarged prostate, bone marrow problems, trouble urinating, or seizures. Also tell your doctor if you have breathing problems, such as COPD, asthma, or sleep apnea.

  • This medicine may cause the following problems:Breathing problems, which could be life-threateningNeuroleptic malignant syndrome (a nerve disorder that can be life-threatening)Liver problems

  • Use in children: Give the medicine exactly as directed by the child's doctor. Too much of this medicine can cause death in a young child. Do not give this medicine to a child younger than 2 years old, unless your doctor tells you to.

  • This medicine may make you dizzy or drowsy. Do not drive or do anything that could be dangerous until you know how this medicine affects you.

  • Tell any doctor or dentist who treats you that you are using this medicine. This medicine may affect certain medical test results.

  • This medicine may make your skin more sensitive to sunlight. Wear sunscreen. Do not use sunlamps or tanning beds.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

  • Yellow skin or eyes

  • Yellow skin or eyes

  • Tell your doctor if you are pregnant or breastfeeding, or if you have liver disease, heart or blood vessel disease, glaucoma, a stomach ulcer, bowel problems, an enlarged prostate, bone marrow problems, trouble urinating, seizures, or an allergy to sulfites. Also tell your doctor if you have breathing problems, such as COPD, asthma, or sleep apnea.

  • This medicine may cause the following problems:Breathing problems, which could be life-threateningTissue damage where the medicine is injected Neuroleptic malignant syndrome (a nerve disorder that can be life-threatening)Liver problems

  • This medicine may make you drowsy or dizzy. Do not drive or do anything that could be dangerous until you know how this medicine affects you.

  • Tell any doctor or dentist who treats you that you are using this medicine. This medicine may affect certain medical test results.

  • This medicine may make your skin more sensitive to sunlight. Wear sunscreen. Do not use sunlamps or tanning beds.

  • Seizures

  • Trouble breathing, slow breathing

  • Twitching or muscle movements you cannot control

  • This medicine may cause the following problems:Breathing problems, which could be life-threateningNeuroleptic malignant syndrome (a nerve disorder that can be life-threatening)Liver problems

  • Use in children: Give the medicine exactly as directed by the child's doctor. Too much of this medicine can cause death in a young child. Do not give this medicine to a child younger than 2 years old, unless your doctor tells you to.

  • Tell any doctor or dentist who treats you that you are using this medicine. This medicine may affect certain medical test results.

  • Tell your doctor if you are pregnant or breastfeeding, or if you have liver disease, heart or blood vessel disease, glaucoma, a stomach ulcer, bowel problems, an enlarged prostate, bone marrow problems, trouble urinating, or seizures. Also tell your doctor if you have breathing problems, such as COPD, asthma, or sleep apnea.

  • This medicine may make you dizzy or drowsy. Do not drive or do anything that could be dangerous until you know how this medicine affects you.

  • This medicine may make your skin more sensitive to sunlight. Wear sunscreen. Do not use sunlamps or tanning beds.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

  • Yellow skin or eyes

Phenergan interactions

  • This medicine may make your skin more sensitive to sunlight. Wear sunscreen. Do not use sunlamps or tanning beds.

  • This medicine may make you dizzy or drowsy. Do not drive or do anything that could be dangerous until you know how this medicine affects you.

  • Tell any doctor or dentist who treats you that you are using this medicine. This medicine may affect certain medical test results.

  • Use in children: Give the medicine exactly as directed by the child's doctor. Too much of this medicine can cause death in a young child. Do not give this medicine to a child younger than 2 years old, unless your doctor tells you to.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

  • Tell your doctor if you use anything else that makes you sleepy. Some examples are allergy medicine, narcotic pain medicine, and alcohol.

  • Some medicines can affect how promethazine works. Tell your doctor if you are also using an MAO inhibitor (MAOI).

  • Some medicines can affect how promethazine works. Tell your doctor if you are also using an MAO inhibitor (MAOI).

  • Tell your doctor if you use anything else that makes you sleepy. Some examples are allergy medicine, narcotic pain medicine, and alcohol.

  • This medicine may make you drowsy or dizzy. Do not drive or do anything that could be dangerous until you know how this medicine affects you.

  • Tell any doctor or dentist who treats you that you are using this medicine. This medicine may affect certain medical test results.

  • This medicine may make your skin more sensitive to sunlight. Wear sunscreen. Do not use sunlamps or tanning beds.

  • Some medicines can affect how promethazine works. Tell your doctor if you are also using an MAO inhibitor (MAOI).

  • Tell your doctor if you use anything else that makes you sleepy. Some examples are allergy medicine, narcotic pain medicine, and alcohol.

  • Use in children: Give the medicine exactly as directed by the child's doctor. Too much of this medicine can cause death in a young child. Do not give this medicine to a child younger than 2 years old, unless your doctor tells you to.

  • This medicine may make you dizzy or drowsy. Do not drive or do anything that could be dangerous until you know how this medicine affects you.

  • Tell any doctor or dentist who treats you that you are using this medicine. This medicine may affect certain medical test results.

  • This medicine may make your skin more sensitive to sunlight. Wear sunscreen. Do not use sunlamps or tanning beds.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Phenergan side effects

Serious Side Effects

  • Seizures

  • Lightheadedness or fainting

  • Trouble breathing, slow breathing

  • Yellow skin or eyes

  • Twitching or muscle movements you cannot control

  • Seeing or hearing things that are not there (especially in children)

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

  • Fever, sweating, confusion, uneven heartbeat, muscle stiffness

  • Pain, burning, redness, or swelling where the needle is placed

  • Seeing or hearing things that are not there (especially in children)

  • Twitching or muscle movements you cannot control

  • Yellow skin or eyes

  • Lightheadedness or fainting

  • Seizures

  • Trouble breathing, slow breathing

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

  • Fever, sweating, confusion, uneven heartbeat, muscle stiffness

  • Seeing or hearing things that are not there (especially in children)

  • Twitching or muscle movements you cannot control

  • Lightheadedness or fainting

  • Trouble breathing, slow breathing

  • Seizures

  • Yellow skin or eyes

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

  • Fever, sweating, confusion, uneven heartbeat, muscle stiffness

Less Serious Side Effects

  • Nausea, vomiting, constipation

  • Blurred vision

  • Nausea, vomiting, constipation

  • Blurred vision

  • Blurred vision

  • Nausea, vomiting, constipation