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Phenergan (injection)

Generic name: promethazine (injection)

Brand names: Phenergan

Last updated November 3, 2026 0 views
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What is promethazine injection?

Promethazine is used to treat or prevent nausea and vomiting caused by anesthesia or surgery, certain types of allergic reactions, pain from surgery or childbirth, motion sickness, and to calm patients before surgery or medical procedures.

Promethazine (injection) is typically given when a person cannot take the medication by mouth.

Promethazine injection may also be used for reasons not listed in this medication guide.

This section was rewritten for readability and reviewed for meaning.

Warnings

Promethazine should never be given to a child younger than 2 years old. Promethazine can cause serious breathing problems or death in very young children.

Let your caregivers know if you feel any burning, pain, or swelling around the IV needle when promethazine is injected.

Contact your doctor immediately if you later notice symptoms throughout your body, such as: severe pain, burning, swelling, numbness, cold feeling, severe irritation, skin changes, or discoloration in your fingers or toes.

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Before taking this medicine

You should not take this medicine if you are allergic to promethazine or to similar medicines like chlorpromazine, fluphenazine, mesoridazine, perphenazine, prochlorperazine, thioridazine, or trifluoperazine.

Promethazine should not be given to a child younger than 2 years old. Promethazine can cause severe breathing problems or death in very young children.

Tell your doctor if you have ever had:

  • asthma, chronic obstructive pulmonary disease (COPD), sleep apnea, or other breathing disorder;
  • a sulfite allergy;
  • a history of seizures;
  • a weak immune system (bone marrow depression);
  • glaucoma;
  • enlarged prostate or problems with urination;
  • stomach ulcer or obstruction;
  • heart disease or high blood pressure;
  • liver disease; or
  • if you have ever had a serious side effect while using promethazine or any other phenothiazine.

Tell your doctor if you are pregnant or breastfeeding.

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Promethazine injection side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Phenergan may cause serious side effects. Call your doctor right away if you have:

  • pain, burning, irritation, or skin changes where the injection was given;
  • severe pain, swelling, numbness, cold feeling, or discoloration in your fingers or toes;
  • weak or shallow breathing;
  • hallucinations;
  • uncontrolled muscle movements in your face (chewing, lip smacking, frowning, tongue movement, blinking or eye movement);
  • jaundice (yellowing of the skin or eyes);
  • easy bruising or bleeding (nosebleeds, bleeding gums);
  • sudden weakness or feeling unwell, fever, chills, sore throat, mouth sores, red or swollen gums, trouble swallowing; or
  • severe nervous system reaction - very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might faint.

Common side effects of Phenergan may include:

  • drowsiness, dizziness;
  • ringing in your ears;
  • double vision;
  • feeling nervous;
  • dry mouth; or
  • tiredness, sleep problems (insomnia).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

This section was rewritten for readability and reviewed for meaning.

How is promethazine injection given?

Promethazine is injected deep into a muscle. A healthcare provider will give you this injection.

Tell your caregivers if you feel any burning, pain, or swelling around the IV needle when promethazine is injected.

Promethazine injection is usually given for only a short time until no longer needed or until you can take promethazine by mouth.

This medicine can cause unusual results with certain medical tests. Tell any doctor who treats you that you have recently received promethazine injection.

What happens if I miss a dose?

Since promethazine (injection) is given by a healthcare professional, you are not likely to miss a dose.

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What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include overactive reflexes, loss of coordination, severe drowsiness or weakness, fainting, dilated pupils, weak or shallow breathing, or seizure (convulsions).

This medicine may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert. Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.

Avoid exposure to sunlight or tanning beds. Promethazine can make you sunburn more easily. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

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What other drugs will affect promethazine injection?

Using promethazine (injection) with other drugs that make you drowsy can make you feel even more tired. Check with your doctor before taking opioid medication, a sleeping pill, a muscle relaxer, or any medicine for anxiety or seizures.

Other drugs might affect promethazine (injection), including prescription and over-the-counter medicines, vitamins, and herbal products. Inform your doctor about all other medicines you are using.

This section was rewritten for readability and reviewed for meaning.

Frequently asked questions

  • Par promethazine with codeine vs Hi-Tech promethazine with codeine?
  • How long does promethazine stay in your system?

Related medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
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Content is provided for education and is not medical advice. See our medical disclaimer.