BMA Concise Guide to Medicine & Drugs


Brand names ZypAdhera, Zyprexa, Zyprexa Velotab

Used in the following combined preparations None


Drug group Antipsychotic drug

Overdose danger rating Medium

Dependence rating Low

Prescription needed Yes

Available as generic No


Olanzapine is an atypical antipsychotic drug prescribed for the treatment of schizophrenia and mania and for long-term treatment of bipolar disorder. It works by blocking several different chemical transmitters in the brain, including dopamine, histamine, and serotonin.

In schizophrenia, the drug can be used to treat both “positive” symptoms (delusions, hallucinations, and thought disorders) and “negative” symptoms (blunted affect, emotional and social withdrawal). In mania, olanzapine can be used alone or in combination with other drugs.

Olanzapine injection is used short term for its calming effects in agitation associated with schizophrenia or mania.


Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets, dispersible tablets, injection.

Frequency and timing of doses Once daily (tablets); 1–2 x daily (injection).

Adult dosage range Schizophrenia 10mg (starting dose). Mania 15mg if used alone or 10mg if used in combination with other drugs (starting dose). For all conditions, the dose can be adjusted between 5mg and 20mg daily (tablets) and 5mg and 10mg daily (injection).

Onset of effect 4–8 hours (tablets); 15–45 minutes (injection).

Duration of action 30–38 hours.

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children. Protect from light.

Missed dose Take as soon as you remember. If your next dose is due within 8 hours take a single dose now and skip the next.

Stopping the drug Do not stop the drug without consulting your doctor; symptoms may recur.

Exceeding the dose An occasional unintentional extra dose is unlikely to cause problems. Large overdoses may cause unusual drowsiness, depressed breathing, and low blood pressure. Notify your doctor.


Unusual drowsiness, increased appetite, and weight gain are the most common adverse effects of olanzapine. Discuss with your doctor if these are severe. Dizziness, fainting, and a rash are also common and should be notified to your doctor. Rarely, difficulty in urinating may occur; if so, discuss with your doctor. Long-term use may cause movement problems (see Prolonged use).


Sedatives All drugs that have a sedative effect on the central nervous system may increase the sedative effects of olanzapine.

Carbamazepine and smoking These can reduce the effects of olanzapine.

Diabetic medication Olanzapine can affect diabetic control. Dosage of diabetic medications may need to be adjusted.

Ciprofloxacin This can increase the effects of olanzapine.


Be sure to tell your doctor if:

· You have kidney or liver problems.

· You have diabetes.

· You have glaucoma.

· You have epilepsy.

· You have had, or are at risk of having, a stroke.

· You are taking other medicines.

Pregnancy Safety not established. Discuss with your doctor.

Breast-feeding Safety not established. Discuss with your doctor.

Infants and children Not recommended.

Over 60 Reduced dose may be necessary. Increased risk of stroke with long-term use.

Driving and hazardous work Avoid such activities until you have learned how olanzapine affects you because the drug can cause unusual drowsiness.

Alcohol Avoid. Alcohol increases the sedative effects of this drug.


Prolonged use of olanzepine may rarely cause tardive dyskinesia, in which there are involuntary movements of the tongue and face. There is also an increased risk of developing diabetes and raised blood lipid levels. With long-term use in elderly patients, olanzapine also carries a greater risk of stroke than some other antipsychotic drugs.