Nozinan (Levomepromazine Maleate)

Levomepromazine is a broad‑spectrum antipsychotic that acts on multiple neurotransmitter pathways, particularly dopamine and serotonin receptors.

• Severe agitation and psychosis: helps calm acute episodes in adult psychiatric patients.
• Nausea and vomiting in palliative care: reduces refractory symptoms when other anti‑emetics fail.
• Painful muscle spasm and terminal delirium: provides sedation and comfort in end‑of‑life settings.

• Levomepromazine blocks dopamine D2 receptors and antagonises several serotonin (5‑HT2), histamine (H1) and muscarinic receptors. This broad receptor blockade reduces dopaminergic neurotransmission, producing antipsychotic, anti‑emetic and sedative effects, while also influencing pain pathways and autonomic tone.

Levomepromazine may cause a range of adverse reactions, from mild to potentially life‑threatening.

Common Side Effects

• Drowsiness: increased sleepiness or fatigue.
• Dry mouth: reduced salivation causing discomfort.
• Orthostatic hypotension: light‑headedness on standing.
• Constipation: slowed gastrointestinal motility.
• Blurred vision: temporary visual disturbances.
• Weight gain: increased appetite and body weight.

Serious or Rare Side Effects

• Extrapyramidal symptoms: muscle rigidity, tremor or akathisia.
• Neuroleptic malignant syndrome: high fever, rigidity and autonomic instability.
• Severe hypotension: sudden drop in blood pressure.
• Cardiac arrhythmias: irregular heart rhythm, especially QT prolongation.
• Agranulocytosis: markedly reduced white‑blood‑cell count.
• Hepatotoxicity: liver enzyme elevation or injury.

Before initiating Levomepromazine therapy, clinicians should assess patient‑specific risk factors and monitor for adverse events.

• Cardiovascular assessment: evaluate for pre‑existing hypotension or cardiac disease.
• Metabolic screening: check liver and renal function prior to treatment.
• CNS monitoring: observe for excessive sedation or extrapyramidal signs.
• Drug‑interaction review: avoid concurrent use with other strong dopamine antagonists.
• Pregnancy and lactation: weigh benefits against potential fetal or neonatal risks.
• Store at below 25°C: keep in the original container, protect from moisture and light.

Levomepromazine interacts with several drug classes; careful review is essential to minimise adverse outcomes.

Major Interactions (Avoid)

• Other antipsychotics: additive dopamine blockade increasing extrapyramidal risk.
• QT‑prolonging agents: combined effect may precipitate serious arrhythmias.
• CNS depressants (e.g., benzodiazepines, opioids): heightened sedation and respiratory depression.

Moderate Interactions (Monitor Closely)

• Antihypertensives: may amplify orthostatic hypotension.
• Anticholinergic drugs: increase risk of severe dry mouth and constipation.
• CYP2D6 inhibitors: can raise levomepromazine plasma levels, requiring dose adjustment.