Methotrimeprazine Side Effects

Applies to methotrimeprazine: intramuscular solution.

General

The most commonly reported side effects included dry mouth, somnolence, hypotension, and convulsions.^[Ref]

Cardiovascular

Common (1% to 10%): Heat stroke, hypotension, QT prolongation

Uncommon (0.1% to 1%): Tachycardia, venous thromboembolism/fatal venous thromboembolism

Rare (0.01% to 0.1%): Cardiac arrest, cardiac rhythm disturbances, ventricular arrhythmias, ventricular fibrillation, ventricular tachycardia

Frequency not reported: Atrial arrhythmias, atrioventricular (AV) block, cardiac arrhythmias, deep vein thrombosis, ECG changes, orthostatic hypotension, postural hypotension, ST depression, sudden cardiac death, Torsade de pointes, T-wave changes, U-wave changes^[Ref]

Heat stroke occurred in hot and humid conditions.

Hypotension occurred with use, especially in older patients.

Orthostatic hypotension occurred with high initial oral doses or with initial parenteral doses.

Patients who develop Torsade de pointes should discontinue treatment and should be given therapy to correct imbalances (e.g., acid base disturbances, electrolyte imbalances, hypoxia).^[Ref]

Nervous system

Drowsiness, sedation, and/or somnolence usually occurred early in treatment, but gradually disappeared after the first few weeks and/or with a dose adjustment.

Extrapyramidal syndrome includes akathisia, akinesia with/without hypertonia (partially relieved by antiparkinsonian agents), hyperkinetic-hypertonic movements, and/or motor excitation. Extrapyramidal effects typically occurred after prolonged, high-dose treatment; the effect was treated with reductions in dose or with the addition of an antiparkinsonian agent.

Oculogyric crises, spasmodic torticollis, and trismus occurred with early dyskinesia.

Parkinsonism was prolonged with higher doses.

Tardive dyskinesia occurred with prolonged use, may recur if the neuroleptic is discontinued, and may resolve upon rechallenge or with an increase in dose. Antiparkinsonian agents may cause symptom exacerbation.^[Ref]

Common (1% to 10%): Drowsiness, sedation, somnolence

Uncommon (0.1% to 1%): Convulsions, parkinsonism

Rare (0.01% to 0.1%): Extrapyramidal effects

Frequency not reported: Akathisia, akinesia with/without hypertonia, anticholinergic syndrome, early dyskinesia, epileptic seizures, hyperkinetic-hypertonic movements, motor excitation, neuroleptic malignant syndrome, oculogyric crises, spasmodic torticollis, tardive dyskinesia, trismus^[Ref]

Gastrointestinal

Common (1% to 10%): Dry mouth

Uncommon (0.1% to 1%): Constipation/severe constipation

Very rare (less than 0.01%): Fatal necrotizing enterocolitis/necrotizing enterocolitis

Frequency not reported: Paralytic ileus^[Ref]

Severe constipation may occur with treatment, and laxatives may be needed to treat the condition. Patients should report any new or worsening constipation to their healthcare provider.^[Ref]

Other

Asthenia usually occurred early in treatment, but gradually disappeared after the first few weeks.^[Ref]

Common (1% to 10%): Asthenia

Frequency not reported: Neonatal drug withdrawal syndrome, sudden death/unexplained sudden death, thermoregulation disorders^[Ref]

Hematologic

Uncommon (0.1% to 1%): Agranulocytosis, raised erythrocyte sedimentation rate (ESR)

Frequency not reported: Granulocytopenia, leukocytopenia, neutropenia^[Ref]

Hypersensitivity

Uncommon (0.1% to 1%): Allergic skin reactions/allergic dermatitis^[Ref]

Dermatologic

Uncommon (0.1% to 1%): Photosensitivity/photosensitivity reaction^[Ref]

Genitourinary

Uncommon (0.1% to 1%): Urinary retention

Very rare (less than 0.01%): Priapism

Frequency not reported: Amenorrhea, galactorrhea^[Ref]

Metabolic

Uncommon (0.1% to 1%): Weight gain

Frequency not reported: Acid base disturbances, diabetic ketoacidosis, electrolyte abnormalities, glucose intolerance/impaired glucose tolerance, hyperglycemia, hyponatremia^[Ref]

Weight gain usually occurred in patients receiving prolonged, high-dose treatment.^[Ref]

Hepatic

Rare (0.01% to 0.1%): Cholestatic jaundice without liver damage, jaundice

Frequency not reported: Cholestatic liver injury, hepatocellular liver injury, mixed liver injury^[Ref]

Psychiatric

Frequency not reported: Anxiety reactions, confusional state, delirium, frigidity, impotence, indifference, mood changes^[Ref]

Endocrine

Hyperprolactinemia may result in amenorrhea, frigidity, galactorrhea, gynecomastia, and impotence.^[Ref]

Frequency not reported: Gynecomastia, hyperprolactinemia, hypogonadism, syndrome of inappropriate antidiuretic hormone (SIADH) secretion^[Ref]

Respiratory

Frequency not reported: Fatal pulmonary embolism/pulmonary embolism, hypoxia^[Ref]

Ocular

Frequency not reported: Accommodation disorder, brown deposits in the anterior segment of the eye^[Ref]

Brown deposits in the anterior segment of the eye usually do not affect vision, and are caused by accumulation of the drug.^[Ref]

Musculoskeletal

Frequency not reported: Decreased bone mineral density^[Ref]

Immunologic

Frequency not reported: Positive serology for antinuclear antibodies without clinical lupus erythematosus^[Ref]

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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