Drug Information

Quetiapine is used to treat symptoms associated with psychiatric disorders, such as delusions, hallucinations, disorganized thinking and speech, and bizarre behavior. It is in a class of antipsychotic drugs known as dibenzapines.

Common brand names:

Seroquel, Seroquel XR

Summary of Interactions with Vitamins, Herbs, & Foods

Types of interactions: Beneficial Adverse Check

Replenish Depleted Nutrients

  • none

Reduce Side Effects

  • none

Support Medicine

  • Glycine

    In a small double-blind study, people with schizophrenia being treated with risperidone 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.

Reduces Effectiveness

  • none

Potential Negative Interaction

  • Grapefruit
    Ingestion of grapefruit or grapefruit juice may increase the absorption of quietiapine by inhibiting an enzyme that breaks down the drug in the intestinal tract 2. Consumption of grapefruit products could therefore increase both the effectiveness and the adverse effects of this drug. People taking quietiapine should not use grapefruit products without medical supervision.
    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Explanation Required 

  • none

The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.

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. Fuhr U. Drug interactions with grapefruit juice. Extent, probable mechanism and clinical relevance. Drug Saf 1998;18:251-72.