Olanzapine Health Article

Definition

Olanzapine is classified as an atypical antipsychotic drug. It is available in the United States under the brand names Zyprexa and Zyprexa Zydis.

Purpose

Olanzapine is used to treat schizophrenia, to control manic episodes of bipolar disorder (manic-depressive disorder), or to treat dementia related to Alzheimer's disease.

Description

Olanzapine is thought to modify the actions of several chemicals in the brain. Onlanzapine is chemically related to another atypical antipsychotic agent, clozapine, but differs both chemically and pharmacologically from the earlier phenothiazine antipsychotics.

Olanzapine is available as 2.5-mg, 5-mg, 7.5-mg, 10-mg, 15-mg, and 20-mg tablets that can be swallowed (Zyprexa) and 5-mg, 10-mg, 15-mg, and 20-mg tablets that disintegrate when placed under the tongue (Zyprexa Zydis). Olanzapine is broken down by the liver.

Recommended dosage

The dosage of olanzapine varies depending upon the reason for its use. When used to treat schizophrenia, 5–10 mg is the typical starting dosage. If dosage adjustments are needed, increases are made in 5-mg increments once a week. When treating schizophrenia, a total daily dosage of 10–15 mg is usually effective. When olanzapine is used to treat acute manic episodes, initial doses of olanzapine are often 10–15 mg; 20 mg per day may be needed for maximum effect. The safety of doses greater than 20 mg per day has not been determined.

Olanzapine is eliminated from the body more quickly in young people than in older (over age 60) individuals, in men than in women, and in smokers faster than in non-smokers. Dosage adjustments may be needed based upon individual patient characteristics.

Precautions

Caution should be used in patients with heart disease because the drug may cause blood pressure to fall too low resulting in dizziness, rapid heartbeats, or fainting. Olanzapine should be used carefully in people with known seizure disorders since olanzapine may alter properties of the brain making seizures occur more easily. People with liver disease should have their liver function monitored regularly while taking olanzapine. Women who are pregnant or breast-feeding should not take olanzapine. People with phenylketonuria, a disorder in which the body is unable to metabolize a protein called phenylalanine, should avoid olanzapine disintegrating tablets, because this form of the drug contains phenylalanine.