Promethazine DM Side Effects

Generic name: dextromethorphan / promethazine

Medically reviewed by Drugs.com. Last updated on Jan 31, 2024.

Note: This document provides detailed information about Promethazine DM Side Effects associated with dextromethorphan / promethazine. Some dosage forms listed on this page may not apply specifically to the brand name Promethazine DM.

Applies to dextromethorphan / promethazine: oral syrup.

Important warnings This medicine can cause some serious health issues

Promethazine can slow the breathing, which has caused death in very young children.

Do not use this medicine in a child younger than 2 years old.

Follow all directions when giving the medicine to a child 2 years or older.

Do not use dextromethorphan and promethazine if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.

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

Stop using this medicine and call your doctor at once if you have:

• weak or shallow breathing, breathing that stops during sleep;

• unusual restlessness or excitement;

• uncontrolled muscle movements in your neck, tongue, or eyes;

• fast, slow, or uneven heart rate;

• hallucinations, ringing in your ears;

• a seizure;

• fever, chills, weakness;

• easy bruising, unusual bleeding;

• yellowing of your skin or eyes; or

• severe nervous system reaction--very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out.

Common side effects may include:

• drowsiness, dizziness;

• dry mouth, nose, or throat;

• blurred vision;

• nausea, vomiting; or

• loss of coordination.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

For healthcare professionals

Applies to dextromethorphan / promethazine: oral syrup.

General adverse events

The most common adverse reaction is somnolence.

Nervous system

Dextromethorphan:

• Frequency not reported: Drowsiness, dizziness

Promethazine:

• Frequency not reported: Drowsiness, dizziness, sedation, somnolence, tremors, convulsive seizures, extrapyramidal symptoms such as oculogyric crisis, torticollis, and tongue protrusion, incoordination, neuroleptic malignant syndrome, serotonin syndrome, abnormal movements^[Ref]

Respiratory

Promethazine:

• Frequency not reported: Asthma, nasal stuffiness, respiratory depression (potentially fatal), apnea^[Ref]

Gastrointestinal

Dextromethorphan:

• Frequency not reported: Gastrointestinal disturbances

Promethazine:

• Frequency not reported: Dry mouth, nausea, vomiting^[Ref]

Psychiatric

Promethazine:

• Frequency not reported: Disorientation, euphoria, nervousness, insomnia, excitation, catatonic-like states, hysteria, hallucinations, confusion, nightmares, delirium agitated behavior, hyperexcitability

Cardiovascular

Promethazine:

• Frequency not reported: Increased or decreased blood pressure, tachycardia, bradycardia, faintness^[Ref]

Hepatic

Promethazine:

• Frequency not reported: Jaundice^[Ref]

Hematologic

Promethazine:

• Frequency not reported: Leukopenia, thrombocytopenia, thrombocytopenic purpura, agranulocytosis^[Ref]

Dermatologic

Promethazine:

• Frequency not reported: Dermatitis, photosensitivity, urticaria^[Ref]

Hypersensitivity

Promethazine:

• Frequency not reported: Angioneurotic edema^[Ref]

Other

Promethazine:

• Frequency not reported: Lassitude, tinnitus, fatigue^[Ref]

Ocular

Promethazine:

• Frequency not reported: Blurred vision, diplopia^[Ref]

Further information

Promethazine DM side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer