1. Introduction
Olanzapine is an atypical antipsychotic used to treat schizophrenia, bipolar disorder, and related psychotic conditions. It works by modulating dopamine and serotonin activity in the brain, reducing psychotic symptoms and stabilising mood. It is available in oral, orodispersible, and injectable formulations.
2. Indications
- Schizophrenia (adults and adolescents ≥13 years)
- Bipolar disorder (manic or mixed episodes)
- Maintenance therapy in bipolar disorder to prevent relapse
- Adjunctive therapy in treatment-resistant depression (off-label)
- Acute agitation associated with schizophrenia or bipolar mania (intramuscular formulation)
3. Dosage
Adults:
- Schizophrenia and Bipolar Disorder:
- Initial dose: 5–10 mg once daily.
- Usual dose: 10–20 mg/day.
- Maximum dose: 20 mg/day.
- Acute Agitation (IM injection):
- 5–10 mg intramuscularly as a single dose; may repeat every 2–4 hours as needed (maximum 20 mg/day).
Elderly:
- Start with 5 mg once daily; adjust based on response and tolerability.
Adolescents (13–17 years):
- Start with 2.5–5 mg once daily; usual dose: 10 mg/day.
4. Administration
- Oral tablets and orodispersible formulations can be taken with or without food.
- Intramuscular injections are administered under medical supervision in a healthcare setting.
- Take at the same time each day to maintain consistent blood levels.
5. Forms Available
- Tablets: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg
- Orodispersible tablets: 5 mg, 10 mg, 15 mg, 20 mg
- Intramuscular injection: 10 mg vial
6. Side Effects
6.1 Common Side Effects:
- Weight gain
- Sedation or drowsiness
- Increased appetite
- Dry mouth
- Constipation
6.2 Less Common Side Effects:
- Dizziness
- Orthostatic hypotension
- Increased prolactin levels
6.3 Rare but Serious Side Effects:
- Neuroleptic malignant syndrome (NMS)
- Tardive dyskinesia (involuntary movements)
- Hyperglycaemia and diabetes mellitus
- Severe allergic reactions (e.g., angioedema)
7. Warnings
- Metabolic Effects: Olanzapine is associated with weight gain, dyslipidaemia, and hyperglycaemia; monitor metabolic parameters regularly.
- Neuroleptic Malignant Syndrome (NMS): Rare but potentially fatal; discontinue if symptoms such as hyperthermia, muscle rigidity, or altered consciousness occur.
- Tardive Dyskinesia: Risk increases with prolonged use; consider dose reduction or discontinuation if symptoms develop.
8. Precautions
- Use cautiously in patients with a history of seizures, diabetes, or cardiovascular disease.
- Avoid abrupt discontinuation to reduce the risk of withdrawal symptoms, such as insomnia or rebound psychosis.
- Monitor for behavioural changes, particularly in adolescents, as there is an increased risk of suicidal ideation.
9. Interactions
- CYP1A2 inducers (e.g., smoking, carbamazepine): Decrease Olanzapine levels; dosage adjustment may be needed.
- CYP1A2 inhibitors (e.g., fluvoxamine): Increase Olanzapine levels, enhancing side effects.
- CNS depressants (e.g., benzodiazepines, alcohol): Additive sedation and risk of respiratory depression.
- Antihypertensives: Additive hypotensive effects.
10. Monitoring Parameters
- Weight and BMI at baseline, then periodically.
- Fasting blood glucose and lipid profile at baseline and during therapy.
- Liver function tests if clinically indicated.
- Monitor for signs of tardive dyskinesia or neuroleptic malignant syndrome.
11. Use in Children
- Approved for schizophrenia and bipolar disorder in adolescents (≥13 years). Use with caution due to a higher risk of weight gain and metabolic side effects.
12. Use in Pregnancy
- Category C: Use only if the potential benefits outweigh the risks. Exposed neonates may experience withdrawal symptoms or extrapyramidal side effects.
13. Use in Elderly
- Use cautiously in elderly patients with dementia-related psychosis due to an increased risk of cerebrovascular events and mortality. Start with lower doses.
14. Use in Kidney Disease
- No specific dose adjustment required, as Olanzapine is primarily metabolised by the liver.
15. Use in Liver Disease
- Use cautiously in patients with significant hepatic impairment. Dose adjustment may be necessary based on clinical response.
16. Patient Counselling Points
- Take Olanzapine at the same time daily to maintain consistent levels.
- Avoid alcohol and other sedatives to prevent excessive drowsiness.
- Inform your doctor if you experience excessive weight gain, severe drowsiness, or symptoms of high blood sugar (e.g., excessive thirst, frequent urination).
- Do not stop taking Olanzapine without consulting your doctor, as this may worsen symptoms.
- Report any involuntary movements or persistent fever and muscle stiffness immediately.
17. Table of Brand Names, Manufacturer, and Prices in USD
Brand Name | Manufacturer | Strength/Dosage Form | Price (USD) |
---|---|---|---|
Zyprexa | Eli Lilly | 10 mg Tablet | $250 (30 tablets) |
Zyprexa Zydis | Eli Lilly | 10 mg Orodispersible Tablet | $270 (30 tablets) |
Generic Olanzapine | Various | 10 mg Tablet | $50 (30 tablets) |
18. 15 FAQs (Frequently Asked Questions)
1. What is Olanzapine used for?
Olanzapine is used to treat schizophrenia, bipolar disorder, and related psychotic conditions.
2. How does Olanzapine work?
It modulates dopamine and serotonin activity in the brain to stabilise mood and reduce psychotic symptoms.
3. Can Olanzapine cause weight gain?
Yes, weight gain is a common side effect due to increased appetite and metabolic changes.
4. How long does Olanzapine take to work?
Symptoms may begin to improve within 1–2 weeks, but full effects may take several weeks.
5. Is Olanzapine safe for children?
Yes, it is approved for use in adolescents (≥13 years) with schizophrenia or bipolar disorder, but requires close monitoring.
6. Can Olanzapine cause drowsiness?
Yes, drowsiness is a common side effect. It is often taken at bedtime to minimise daytime sedation.
7. Can Olanzapine be used during pregnancy?
It should only be used if the benefits outweigh the risks. Consult your doctor if you are pregnant or planning pregnancy.
8. Does Olanzapine increase blood sugar?
Yes, it can cause hyperglycaemia and increase the risk of diabetes. Regular blood sugar monitoring is recommended.
9. Can I stop taking Olanzapine abruptly?
No, stopping suddenly may cause withdrawal symptoms or worsen your condition. Gradual tapering is advised.
10. Is Olanzapine addictive?
No, it is not addictive, but it should be taken only as prescribed.
11. Can Olanzapine be used for anxiety?
It is not approved for anxiety but may help if anxiety is part of a broader psychiatric condition.
12. Can Olanzapine cause involuntary movements?
Yes, it may cause tardive dyskinesia with long-term use. Inform your doctor if you notice unusual movements.
13. How should Olanzapine be stored?
Store at room temperature, away from moisture and heat.
14. Can Olanzapine cause high cholesterol?
Yes, it can increase cholesterol and triglyceride levels. Regular lipid monitoring is advised.
15. Do I need a prescription for Olanzapine?
Yes, Olanzapine is a prescription-only medication.