Olanzapine is used to treat the symptoms associated with psychotic disorders, especially schizophrenia.
Summary of Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem contradictory. For clarification, read the full article for details about the summarized interactions.
 May be Beneficial: Supportive interaction—Taking these supplements may support or otherwise help your medication work better. | Glycine |
 Avoid: Adverse interaction—Avoid these supplements when taking this medication because taking them together may cause undesirable or dangerous results. | Alcohol Smoking |
| Depletion or interference | None known |
| Side effect reduction/prevention | None known |
| Reduced drug absorption/bioavailability | None known |
An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.
Interactions with Dietary Supplements
Glycine
In a small double-blind study, people with schizophrenia being treated with olanzapine experienced an improvement in their symptoms when glycine was added to their treatment regimen.1 The initial amount of glycine used was 4 grams per day; this was increased gradually over a period of 10 to 17 days to a maximum of 0.8 grams per 2.2 pounds of body weight per day.
Interactions with Foods and Other Compounds
Smoking
Cigarette smoking increases the elimination of risperidone from the body.2 This interaction becomes a problem when an individual who has been taking olanzapine voluntarily starts or quits smoking. People who start smoking while taking risperidone may experience increased disease symptoms, while those who stop smoking while taking the drug may experience increased side effects. Individuals who change their smoking habits while on risperidone should notify their doctor.
Alcohol
Ingestion of alcohol may decrease blood levels of olanzapine by stimulating the liver to break down the drug.3 Consequently, individuals who begin using alcohol while taking olanzapine may experience increased disease symptoms due to the reduced effectiveness of the drug. In addition, people who take antipsychotic agents such as olanzapine should avoid alcohol because it may intensify the effects of the drug on the nervous system and may cause low blood pressure.4
References
1. Heresco-Levy U, Ermilov M, Lichtenberg P, et al. High-dose glycine added to olanzapine and risperidone for the treatment of schizophrenia. Biol Psychiatry 2004;55:165–71.
2. Ereshefsky L. Pharmacologic and pharmacokinetic considerations in choosing an antipsychotic. J Clin Psychiatry 1999;60(Suppl 10):20–30.
3. Ereshefsky L. Pharmacologic and pharmacokinetic considerations in choosing an antipsychotic. J Clin Psychiatry 1999;60(Suppl 10):20–30.
4. Threlkeld DS, ed. Central Nervous System Drugs, Antipsychotic Agents. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparison, 1999, 1693.
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2006-09-07
