Methotrimeprazine Side Effects
Applies to methotrimeprazine: intramuscular solution
Common (1% to 10%): Heat stroke, hypotension, QT prolongation
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]
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]
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%): Dry mouth
Uncommon (0.1% to 1%): Constipation/severe constipation
Very rare (less than 0.01%): Fatal necrotizing enterocolitis/necrotizing enterocolitis
Common (1% to 10%): Asthenia
Frequency not reported: Neonatal drug withdrawal syndrome, sudden death/unexplained sudden death, thermoregulation disorders[Ref]
Asthenia usually occurred early in treatment, but gradually disappeared after the first few weeks.[Ref]
Uncommon (0.1% to 1%): Agranulocytosis, raised erythrocyte sedimentation rate (ESR)
Uncommon (0.1% to 1%): Photosensitivity/photosensitivity reaction[Ref]
Uncommon (0.1% to 1%): Urinary retention
Very rare (less than 0.01%): Priapism
Weight gain usually occurred in patients receiving prolonged, high-dose treatment.[Ref]
Uncommon (0.1% to 1%): Weight gain
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]
Frequency not reported: Gynecomastia, hyperprolactinemia, hypogonadism, syndrome of inappropriate antidiuretic hormone (SIADH) secretion[Ref]
Hyperprolactinemia may result in amenorrhea, frigidity, galactorrhea, gynecomastia, and impotence.[Ref]
Brown deposits in the anterior segment of the eye usually do not affect vision, and are caused by accumulation of the drug.[Ref]
Frequency not reported: Accommodation disorder, brown deposits in the anterior segment of the eye[Ref]
Frequency not reported: Decreased bone mineral density[Ref]
More about methotrimeprazine
1. New Zealand Medicines and Medical Devices Safety Authority "MEDSAFE. Available from: URL: http://www.medsafe.govt.nz/Profs/Datasheet/DSForm.asp." ([2018, Aug 1]):
2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
3. "Product Information. Methoprazine (methotrimeprazine)." AA Pharma Inc, Vaughan , ON.
4. Cerner Multum, Inc. "Canadian Product Information." O 0 (2015):
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.