Olanzapina Nolian (Olanzapine)

Olanzapine acts on central nervous system pathways involved in psychosis and mood regulation.

• Schizophrenia: reduces positive and negative symptoms and helps prevent relapse.
• Bipolar I disorder (manic episodes): stabilises mood and decreases frequency of manic episodes.
• Bipolar I disorder (depressive episodes): used as adjunctive therapy to improve depressive symptoms.
• Schizoaffective disorder: alleviates both psychotic and mood components of the illness.
• Maintenance therapy: supports long‑term symptom control after acute stabilization.

• Olanzapine exerts its antipsychotic effect by antagonising dopamine D2 receptors and serotonin 5‑HT2A receptors, with additional activity at histamine H1, muscarinic and alpha‑adrenergic receptors. This receptor profile modulates dopaminergic and serotonergic neurotransmission, reducing psychotic symptoms and stabilising mood.

Olanzapine may cause a range of adverse reactions that vary in frequency and severity.

Common Side Effects

• Weight gain: increased appetite leading to gradual weight increase.
• Sedation: drowsiness or feeling unusually tired.
• Dry mouth: reduced salivary flow causing oral discomfort.
• Constipation: slowed gastrointestinal motility.
• Elevated triglycerides: rise in blood lipid levels.
• Orthostatic hypotension: drop in blood pressure upon standing.

Serious or Rare Side Effects

• Neuroleptic malignant syndrome: high fever, muscle rigidity, autonomic instability.
• Hyperglycaemia/diabetes mellitus: significant rise in blood glucose.
• Extrapyramidal symptoms: tremor, rigidity, bradykinesia.
• Seizures: occurrence of convulsive episodes.
• Agranulocytosis: marked reduction in white‑blood cell count.
• Severe allergic reactions: rash, swelling, or anaphylaxis.

When prescribing Olanzapine, clinicians should assess individual risk factors and monitor relevant clinical parameters.

• Metabolic monitoring: regularly check weight, fasting glucose, and lipid profile.
• Cardiovascular assessment: evaluate blood pressure and heart rate, especially in patients with pre‑existing hypotension.
• Liver function: perform baseline and periodic liver enzyme tests.
• Pregnancy and lactation: weigh potential benefits against risks; use only if clearly needed.
• Elderly patients: start at lower doses and monitor for sedation and falls.
• Store at ambient temperature: keep below 25 °C, protect from moisture and direct sunlight.

Olanzapine can interact with several drug classes, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Strong CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin): may increase olanzapine plasma levels and risk of toxicity.
• CNS depressants (e.g., benzodiazepines, opioids): can enhance sedation and respiratory depression.

Moderate Interactions (Monitor Closely)

• CYP1A2 inducers (e.g., smoking, carbamazepine, rifampicin): may reduce olanzapine concentrations, diminishing therapeutic effect.
• Anticholinergic agents: additive anticholinergic burden may worsen dry mouth and constipation.
• Antihypertensive drugs: orthostatic hypotension may be potentiated.
• Lithium: combined use may increase the risk of neurotoxicity.
• Alcohol: concurrent use can intensify central nervous system depression.