Meperidine / promethazine Side Effects

Medically reviewed by Drugs.com. Last updated on Apr 7, 2023.

Applies to meperidine / promethazine: injectable solution, oral capsule.

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

Like other opioid medicines, meperidine and promethazine can slow your breathing. Death may occur if breathing becomes too weak.

A person caring for you should seek emergency medical attention if you have slow breathing with long pauses, blue colored lips, or if you are hard to wake up.

Call your doctor at once if you have:

• noisy breathing, sighing, shallow breathing;

• a slow heart rate or weak pulse;

• severe weakness or drowsiness, feeling like you might pass out;

• confusion, hallucinations, feeling anxious or agitated;

• pounding heartbeats or fluttering in your chest;

• loss of balance or coordination;

• sudden ill feeling, fever, chills, sore throat, easy bruising or bleeding;

• vision problems; or

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

Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.

Serious side effects may be more likely in older adults and those who are overweight, malnourished, or debilitated.

Long-term use of opioid medication may affect fertility (ability to have children) in men or women. It is not known whether opioid effects on fertility are permanent.

Common side effects may include:

• dizziness, drowsiness;

• nausea, vomiting, constipation,

• dry mouth;

• flushing (warmth, redness, or tingly feeling); or

• sweating.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.

For Healthcare Professionals

Applies to meperidine / promethazine: injectable solution, oral capsule.

General

The most frequently observed meperidine adverse reactions have included light-headedness, dizziness, sedation, nausea, vomiting, and sweating. Somnolence is the most prominent CNS effect reported with promethazine.^[Ref]

Nervous system

Meperidine:

Common (1% to 10%): Lightheadedness, dizziness, sedation

Rare (less than 0.1%): Extrapyramidal reactions

Frequency not reported: Weakness, headache, tremor, uncoordinated muscle movements

Promethazine:

Common (1% to 10%): Drowsiness

Frequency not reported: Sedation, somnolence, dizziness, confusion, extrapyramidal symptoms, lassitude, tremors, convulsive seizures, neuroleptic malignant syndrome^[Ref]

Hyperexcitability and extrapyramidal movements have been reported following a single dose of promethazine.^[Ref]

Psychiatric

Hyperexcitability and abnormal movements have been reported following a single dose of promethazine.^[Ref]

Meperidine:

Frequency not reported: Euphoria, dysphoria, agitation, transient hallucinations and disorientation

Promethazine:

Frequency not reported: Confusion, disorientation, euphoria, nervousness, insomnia, excitation, catatonic-like states, hysteria, hallucinations, nightmares, agitation, paradoxical reactions, hyperexcitability^[Ref]

Respiratory

Meperidine:

Frequency not reported: Respiratory depression, respiratory arrest

Promethazine:

Frequency not reported: Asthma, respiratory depression, apnea, nasal stuffiness^[Ref]

Gastrointestinal

Meperidine:

Common (1% to 10%): Nausea, vomiting

Frequency not reported: Dry mouth, constipation, biliary-tract spasm

Promethazine:

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

Cardiovascular

Meperidine:

Frequency not reported: Phlebitis, hypotension, tachycardia, bradycardia, palpitation, syncope, circulatory depression, shock, cardiac arrest, faintness

Promethazine:

Frequency not reported: Tachycardia, bradycardia, increased or decreased blood pressure, faintness^[Ref]

Dermatologic

Meperidine:

Common (1% to 10%): Sweating

Frequency not reported: Facial flushing

Promethazine:

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

Other

Promethazine

Frequency not reported: Tinnitus, vertigo^[Ref]

Hematologic

Promethazine:

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

Ocular

Meperidine:

Frequency not reported: Visual disturbances

Promethazine:

Frequency not reported: Blurred vision, diplopia

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

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