Nyzol (Olanzapine)

Olanzapine is an atypical antipsychotic that modulates dopamine and serotonin pathways in several psychiatric conditions.

• Schizophrenia: helps reduce psychotic symptoms such as delusions, hallucinations and thought disorder.
• Bipolar I disorder: stabilises mood and prevents recurrence of depressive or manic phases.
• Manic episodes: rapidly controls elevated mood, hyperactivity and irritability during acute mania.

• Olanzapine acts as an antagonist at dopamine D2 and serotonin 5‑HT2A receptors, while also influencing other neurotransmitter systems including histamine H1, muscarinic and adrenergic receptors. This receptor profile reduces dopaminergic overactivity and modulates serotonergic transmission, contributing to antipsychotic and mood‑stabilising effects.

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

Common Side Effects

• Weight gain: increased appetite leading to noticeable weight increase.
• Sedation: drowsiness or feeling unusually tired.
• Dry mouth: reduced salivation causing discomfort.
• Constipation: slowed gastrointestinal motility.
• Dizziness: light‑headed sensation, especially when standing.
• Increased appetite: heightened desire for food.

Serious or Rare Side Effects

• Neuroleptic malignant syndrome: rare but life‑threatening reaction with fever and muscle rigidity.
• Agranulocytosis: severe drop in white blood cells, increasing infection risk.
• Hyperglycaemia: elevated blood sugar that may precipitate diabetes.
• Seizures: occurrence of convulsive episodes.
• Tardive dyskinesia: involuntary, repetitive movements, often of the face.
• Myocarditis: inflammation of the heart muscle, potentially fatal.

Before initiating therapy, clinicians should assess several safety parameters.

• Metabolic monitoring: regularly check weight, glucose and lipid levels.
• Cardiovascular assessment: evaluate blood pressure and heart rate, especially in patients with pre‑existing disease.
• Seizure history: use with caution in individuals with a history of seizures.
• Elderly patients: avoid use in dementia‑related psychosis due to increased mortality risk.
• Discontinuation: taper gradually to minimise withdrawal or relapse.
• Store at ambient temperature: keep in the original container, protect from moisture and direct sunlight.

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

Major Interactions (Avoid)

• Strong CYP1A2 inhibitors (e.g., fluvoxamine): may raise olanzapine plasma levels.
• Potent CYP3A4 inhibitors (e.g., ketoconazole): increase risk of toxicity.
• CNS depressants (e.g., alcohol, benzodiazepines): can enhance sedation and respiratory depression.

Moderate Interactions (Monitor Closely):\n- Antihypertensives: additive orthostatic hypotension may occur.

• Antidiabetic agents: olanzapine‑induced hyperglycaemia may require dose adjustment.
• Smoking: induces CYP1A2, potentially lowering olanzapine concentrations.