Olanzapine Teva (Olanzapine)

Olanzapine is used in psychiatric care to modulate dopaminergic and serotonergic pathways.

• Schizophrenia: reduces psychotic symptoms such as delusions, hallucinations and thought disorder.
• Bipolar I disorder (manic episodes): controls acute mania and stabilises mood.
• Maintenance treatment of bipolar disorder: helps prevent recurrence of manic or depressive episodes.

• Olanzapine exerts its antipsychotic effect primarily by antagonising dopamine D2 receptors and serotonin 5‑HT2A receptors, while also modulating activity at histamine H1, muscarinic M1‑M5 and adrenergic α1 receptors, resulting in altered neurotransmission across multiple pathways involved in mood and psychosis.

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

Common Side Effects

• Weight gain: increased appetite leading to body mass increase.
• Somnolence: drowsiness or sedation.
• Dry mouth: reduced salivation.
• Constipation: slowed gastrointestinal motility.
• Dizziness: light‑headed feeling, especially on standing.
• Increased appetite: heightened desire for food.

Serious or Rare Side Effects

• Neuroleptic malignant syndrome: life‑threatening reaction with fever and muscle rigidity.
• Agranulocytosis: severe reduction in white blood cells.
• Hyperglycemia/diabetes mellitus: marked elevation of blood glucose.
• Tardive dyskinesia: involuntary, repetitive movements.
• Leukopenia: lowered white blood cell count.
• Seizures: risk of convulsive episodes.

When prescribing Olanzapine, clinicians should consider several safety measures.

• Metabolic monitoring: regularly assess weight, glucose and lipid levels.
• Cardiovascular risk: evaluate patients with existing heart disease.
• Hypersensitivity: avoid use in individuals with known allergy to olanzapine.
• Elderly dementia patients: increased risk of mortality; use with caution.
• Hepatic function: adjust use in patients with liver impairment.
• Store at below 25°C: keep in the original pack, protect from moisture.

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

Major Interactions (Avoid)

• CNS depressants: may enhance sedation and respiratory depression.
• Anticholinergic agents: can worsen anticholinergic burden.
• CYP1A2 inhibitors (e.g., fluvoxamine): increase olanzapine plasma concentrations.
• CYP1A2 inducers (e.g., smoking): reduce olanzapine levels, risking loss of efficacy.
• QT‑prolonging drugs: may increase risk of cardiac arrhythmias.

Moderate Interactions (Monitor Closely)

• Antihypertensives: additive hypotensive effect.
• Antidiabetic agents: may require dose adjustment due to metabolic changes.
• Lithium: potential for increased neurotoxicity.
• SSRIs: heightened risk of serotonin syndrome.
• Anticholinergic medications: monitor for excessive anticholinergic effects.