Malanxin (Olanzapine)

Olanzapine is an atypical antipsychotic used in the management of major psychiatric disorders.

• Schizophrenia: reduces psychotic symptoms such as delusions, hallucinations and thought disorder.
• Bipolar I disorder (manic episodes): stabilises mood and diminishes manic symptoms.
• Bipolar I disorder (depressive episodes, adjunct): improves depressive symptoms when combined with other agents.

• Olanzapine acts primarily as an antagonist at dopamine D2 and serotonin 5‑HT2A receptors, modulating neurotransmission in mesolimbic pathways. It also exhibits affinity for histamine H1, muscarinic, and adrenergic receptors, contributing to its therapeutic and side‑effect profile. By balancing dopaminergic and serotonergic activity, it helps alleviate psychosis and mood instability.

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

Common Side Effects

• Weight gain: increased appetite leading to body‑mass changes.
• Sedation: drowsiness or reduced alertness.
• Dry mouth: reduced salivation causing discomfort.
• Constipation: slowed gastrointestinal motility.

Serious or Rare Side Effects

• Hyperglycaemia: elevated blood glucose requiring monitoring.
• Neuroleptic malignant syndrome: rare but life‑threatening reaction with fever and rigidity.
• Tardive dyskinesia: persistent involuntary movements of facial muscles.

Before initiating Olanzapine, clinicians should consider several safety measures.

• Metabolic monitoring: regularly assess weight, glucose and lipid levels.
• Suicidality assessment: evaluate for suicidal thoughts, especially early in treatment.
• Liver function: check hepatic enzymes in patients with liver disease.
• Elderly use: avoid in dementia‑related psychosis due to increased mortality risk.
• Discontinuation: taper gradually to minimise withdrawal or relapse.
• Store at ambient temperature: keep in original packaging, protect from moisture and direct sunlight.

Olanzapine can interact with other medicines, altering its effectiveness or safety.

Major Interactions (Avoid)

• CYP1A2 inhibitors (e.g., fluvoxamine): may increase olanzapine plasma levels.
• CNS depressants (e.g., alcohol, benzodiazepines): additive sedation and respiratory depression.
• Anticholinergic agents (e.g., diphenhydramine): may exacerbate anticholinergic side effects.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., carbamazepine, phenytoin): may reduce olanzapine concentrations.
• Antihypertensive drugs: potential for additive hypotensive effects.
• Antidiabetic medications: blood‑glucose control may require adjustment.