Lapozan Oro (Olanzapine)

• Olanzapine is an atypical antipsychotic that modulates dopamine and serotonin pathways in psychotic and mood disorders.
• Schizophrenia: reduces positive and negative symptoms, improving overall functioning.
• Bipolar disorder (manic episodes): controls acute mania and helps maintain mood stability.
• Schizoaffective disorder: alleviates psychotic features and mood disturbances.

• Olanzapine exerts its therapeutic effect primarily by antagonising dopamine D2 receptors and serotonin 5‑HT2A receptors. This combined blockade reduces dopaminergic hyperactivity linked to psychosis while modulating serotonergic transmission that influences mood and cognition. The drug also shows affinity for histamine H1, muscarinic M1‑M5 and α1‑adrenergic receptors, contributing to its broader clinical profile and side‑effect spectrum, and may affect other neurotransmitter systems to a lesser extent.

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

Common Side Effects

• Weight gain: increased appetite leading to noticeable weight increase.
• Sedation: drowsiness or feeling unusually sleepy.
• Dry mouth: reduced salivation causing oral discomfort.
• Constipation: slowed gastrointestinal motility.

Serious or Rare Side Effects

• Neuroleptic malignant syndrome: life‑threatening reaction with fever, muscle rigidity and autonomic instability.
• Agranulocytosis: severe drop in white blood cells increasing infection risk.
• Tardive dyskinesia: persistent involuntary movements, especially of the face and tongue.

Before initiating olanzapine therapy, clinicians should evaluate several safety considerations.

• Metabolic monitoring: regularly assess weight, blood glucose and lipid profile.
• Cardiovascular assessment: check for history of orthostatic hypotension or arrhythmias.
• Seizure risk: avoid in patients with uncontrolled epilepsy.
• Elderly caution: use carefully in dementia‑related psychosis due to increased mortality.
• Discontinuation: taper gradually to reduce risk of withdrawal symptoms.
• Store at ambient temperature: keep in original packaging, protect from moisture and direct sunlight.

Olanzapine’s plasma levels can be altered by concomitant medicines, requiring attention to potential interactions.

Major Interactions (Avoid)

• Strong CYP1A2 inhibitors (e.g., fluvoxamine): may markedly increase olanzapine concentrations.
• Carbamazepine or phenytoin (CYP inducers): can substantially lower olanzapine exposure.

Moderate Interactions (Monitor Closely)

• Other CNS depressants (e.g., benzodiazepines, alcohol): may enhance sedation.
• Antihypertensive agents: additive hypotensive effect possible.
• Anticholinergic drugs: may increase anticholinergic burden.
• Lithium: combined use may affect renal function and electrolytes.