Available on prescription. Weight, blood sugar, and cholesterol monitoring is mandatory from the start of treatment.
What it treats
Which conditions is Olanzapine used for?
Overview
What is Olanzapine?
Olanzapine is a second-generation antipsychotic that ranks among the most effective options for schizophrenia in large comparative studies.
It is listed in Kenya's Essential Medicines List 2023 and available as a generic in both public and private facilities. The WHO included IM olanzapine as the preferred injectable option for acute agitation in its updated Essential Medicines List 2023.
Its effectiveness is well established, but olanzapine has a pronounced effect on weight and metabolism, more so than most other antipsychotics. Starting this medicine requires a commitment to regular monitoring and lifestyle support.
How it works
What does it do in the brain?
Formulations in Kenya
How is it available?
Availability across Africa
Where is it available in Africa and what is it called?
| Country | Common Brand Name(s) | Notes |
|---|---|---|
| Kenya | Zyprexa, Olanza, Oleanz, generic | On KEML 2023. Available at public and private facilities. |
| South Africa | Zyprexa, Zalasta, generic | On South Africa EML. Widely available. |
| Nigeria | Zyprexa, Olandus, generic | Available at teaching hospitals and urban pharmacies. |
| Uganda | Generic olanzapine | Available at national referral hospitals. |
| Tanzania | Generic olanzapine | Available at regional referral hospitals. |
| Ethiopia | Generic olanzapine | Available at Amanuel Hospital and major private pharmacies. |
| Ghana | Zyprexa, generic | Available at teaching hospitals. |
| Rwanda | Generic olanzapine | Available within the national health system. |
| Zambia | Generic olanzapine | Available at University Teaching Hospital. |
Side effects
What might you feel while taking it?
These are the most commonly reported effects. Not everyone experiences them, and many settle within the first few weeks.
- Significant weight gain and increased appetite
- Pronounced sedation, especially in the early weeks
- Changes in blood sugar and cholesterol over time
- Dizziness on standing up quickly
- Constipation and dry mouth
- Movement side effects are less common than with older antipsychotics but can occur
- Development of diabetes or significant worsening of blood sugar control
- Very high fever, extreme muscle stiffness, and confusion together. A medical emergency.
- Elderly patients with dementia carry an increased risk of stroke
Risks
Important risks you should understand before taking this medicine
- Olanzapine causes more weight gain and metabolic harm than almost any other antipsychotic. It significantly increases the risk of type 2 diabetes, dyslipidaemia, and metabolic syndrome. Rigorous monitoring and proactive lifestyle intervention are essential from the first day of treatment.
- Diabetes can develop or worsen rapidly in some people on olanzapine, sometimes within weeks of starting. Blood sugar must be checked at baseline, at three months, and then at least annually.
- Stopping olanzapine abruptly causes rapid, severe return of psychotic symptoms. Never stop without a doctor-supervised gradual reduction plan.
- Elderly patients with dementia receiving olanzapine have an increased risk of stroke and death. Use in this population requires explicit specialist justification.
- Smoking significantly affects how olanzapine is processed in the body. People who stop smoking during treatment will have rising olanzapine levels in the blood, which can cause toxicity. Your doctor must be informed immediately if you quit smoking while on this medicine.
Who should not take it
Important warnings before starting
- Known allergy to olanzapine
- Closed-angle glaucoma
- Paralytic ileus (a bowel obstruction condition)
Special care needed
Situations that need extra attention
- Metabolic monitoring is mandatory, not optional
- Tell your doctor if you have diabetes
- Elderly patients with dementia should only receive olanzapine under very careful specialist review
- Inform your doctor immediately if you quit smoking during treatment
If you are pregnant or planning to become pregnant, speak to your doctor. Untreated psychosis during pregnancy carries serious risks that must be weighed carefully.
Olanzapine passes into breast milk. Specialist advice is required before breastfeeding while on this medicine.
Other medicines
Medicines and substances that can interact with it
- Carbamazepine and rifampicin: Speed up the breakdown of olanzapine, potentially reducing its effectiveness.
- Fluvoxamine (an antidepressant): Significantly raises olanzapine levels in the blood, increasing side effects.
- Smoking: Smokers process olanzapine more quickly. Quitting smoking raises olanzapine levels, risking toxicity.
- Alcohol and sedating medicines: Greatly amplifies sedation.
Tests and follow-up
What your doctor will monitor
- Weight and BMI at every appointment
- Fasting blood sugar and HbA1c at baseline, three months, and annually
- Cholesterol and lipid profile at the same intervals
- Blood pressure at initiation
- Movement side effects at each review
Stopping this medicine
What happens if you stop taking it?
In Kenya
What you should know about this medicine in Kenya
Olanzapine's listing in the Kenya EML and growing generic availability has made it more accessible in recent years.
The weight gain and metabolic effects are a genuine clinical concern in Kenya where diabetes and cardiovascular disease are rising. Starting olanzapine should be accompanied by dietary counselling and physical activity guidance from day one.
IM olanzapine for acute agitation management is improving in availability at emergency psychiatric facilities, offering a safer alternative to older injectable options.
Sources
References
- Ministry of Health, Kenya. (2023). Kenya Essential Medicines List 2023. Nairobi: Ministry of Health.
- Ministry of Health, Kenya. (2023). Kenya National Medicines Formulary, 1st Edition. Nairobi: Ministry of Health.
- Leucht, S., et al. (2013). Comparative efficacy and tolerability of 15 antipsychotic drugs. The Lancet, 382(9896), 951-962.
- World Health Organization. (2023). Model List of Essential Medicines, 23rd Edition. Geneva: WHO.