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.