OZITAS (OLANZEPINE INJECTION 10MG)

Indications

• Schizophrenia
• Bipolar disorder (acute manic or mixed episodes)
• Maintenance treatment of bipolar disorder
• Adjunctive treatment of depression (in some cases)

Dosage

Adults: Refer to the BNF for specific dosing information as it varies based on

Mechanism of action

Olanzapine acts as an antagonist at several receptors in the central nervous system, including the D2 dopamine receptor and the 5-HT2A serotonin receptor. By blocking these receptors, olanzapine reduces dopaminergic activity in certain pathways, helping to alleviate symptoms of psychosis and mood disorders. Additionally, olanzapine has affinity for other receptors such as histamine H1 and adrenergic alpha-1 receptors, contributing to its overall pharmacological effects.

Pharmacodynamics

Olanzapine exhibits a complex pharmacological profile with a higher affinity for serotonin receptors compared to dopamine receptors, which may result in a lower incidence of extrapyramidal side effects often associated with traditional antipsychotics. The drug's efficacy in treating schizophrenia is attributed to its ability to modulate dopaminergic and serotonergic neurotransmission, thereby improving both positive symptoms (hallucinations, delusions) and negative symptoms (anhedonia, apathy). In bipolar disorder, olanzapine can help manage acute manic or mixed episodes and maintain mood stabilization.

Pharmacokinetics

Olanzapine is well absorbed following oral administration, with peak plasma concentrations typically occurring within 5 to 8 hours. It has a bioavailability of approximately 60%, and its plasma protein binding is high, around 93%. The drug is extensively metabolized in the liver, primarily via cytochrome P450 enzymes, particularly CYP1A2 and CYP2D6. The elimination half-life ranges from 21 to 54 hours, allowing for flexible dosing schedules. Olanzapine is excreted mainly in urine and feces, with less than 1% being eliminated unchanged in urine.

Contra-indications

• Hypersensitivity to olanzapine or any of its components
• Comatose states
• Severe central nervous system depression
• Use in patients with a history of neuroleptic malignant syndrome

Adverse effects

• Sedation
• Weight gain
• Metabolic syndrome
• Extrapyramidal symptoms
• Dizziness
• Hypotension
• Dry mouth
• Constipation
• Increased cholesterol levels
• Hyperglycemia

Interactions

• CNS depressants may enhance sedative effects
• Antihypertensive agents may have additive hypotensive effects
• Alcohol can increase the sedative effects of olanzapine
• Enzyme inducers or inhibitors can alter olanzapine metabolism

Precautions

• Monitor for signs of metabolic syndrome
• Caution in patients with a history of seizures
• Use with caution in the elderly due to increased risk of side effects
• Monitor for symptoms of neuroleptic malignant syndrome

Pregnancy

Olanzapine should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus. There is limited data on its safety in pregnancy.

Breast-feeding

Olanzapine is excreted in human milk, and caution is advised when administering to breastfeeding women.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• Tablets: 2.5 mg, 5 mg, 10 mg, 15 mg, 20 mg
• Orally disintegrating tablets: 5 mg, 10 mg, 15 mg, 20 mg
• Injection: 10 mg/mL (for intramuscular use)