Levomepromazine Orion (Levomepromazine)

• Levomepromazine is a phenothiazine antipsychotic used in the treatment of psychotic disorders and related symptoms.
• Schizophrenia: reduces psychotic symptoms and stabilizes mood.
• Other psychotic disorders: alleviates hallucinations and delusions.
• Severe agitation: calms acute behavioral disturbances.
• Nausea and vomiting (palliative care): provides anti‑emetic relief in end‑of‑life settings.

• Levomepromazine exerts its effects primarily by antagonizing dopamine D2 receptors in the central nervous system, decreasing dopaminergic neurotransmission associated with psychosis. It also blocks histamine H1, muscarinic acetylcholine, and alpha‑adrenergic receptors, contributing to its sedative, anti‑emetic, and anticholinergic properties. These combined receptor interactions reduce excitatory pathways, lower autonomic tone, and produce calming effects, while the antihistaminic action mitigates allergic‑type responses and contributes to sedation.

Levomepromazine may cause a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Drowsiness: excessive sleepiness or fatigue.
• Dry mouth: reduced salivation causing discomfort.
• Orthostatic hypotension: dizziness when standing.

Serious or Rare Side Effects

• Neuroleptic malignant syndrome: rare but potentially fatal reaction with fever and rigidity.
• Tardive dyskinesia: persistent involuntary movements.
• Severe hypotension: marked blood pressure drop leading to fainting.

When prescribing Levomepromazine, clinicians should consider several safety precautions to minimize risk.

• Assess cardiovascular status: monitor blood pressure and heart rate, especially during dose initiation.
• Evaluate for Parkinsonian symptoms: avoid use in patients with existing extrapyramidal disorders.
• Review hepatic and renal function: adjust dosing in impairment.
• Caution in elderly patients: increased sensitivity to sedation and hypotension.
• Avoid abrupt discontinuation: taper gradually to prevent withdrawal effects.
• Store at ambient temperature: keep below 25°C in original container, protect from moisture.

Levomepromazine can interact with other medicines, affecting its efficacy or safety.

Major Interactions (Avoid)

• CNS depressants (e.g., benzodiazepines, opioids): may cause profound sedation or respiratory depression.
• Anticholinergic agents: additive anticholinergic burden increasing dry mouth, constipation, and urinary retention.

Moderate Interactions (Monitor Closely)

• Antihypertensives: may enhance orthostatic hypotension, requiring blood pressure monitoring.
• Antidiabetic drugs: potential alteration of glucose control.
• QT‑prolonging agents: increased risk of cardiac arrhythmias, monitor ECG.