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Drug Information

Common brand names:


Summary of Interactions with Vitamins, Herbs, & Foods

Types of interactions: Beneficial Adverse Check

Replenish Depleted Nutrients

  • none

Reduce Side Effects

  • Coenzyme Q10

    Phenothiazine drugs like thioridazine can cause changes in heart activity in some people, which might be prevented with coenzyme Q10 supplementation. Therefore, some doctors and pharmacists may recommend coenzyme Q10 supplements to individuals taking thioridazine.

Support Medicine

  • none

Reduces Effectiveness

  • none

Potential Negative Interaction

  • Bacopa

    An animal study found that the effects of chlorpromazine, a drug similar to (perphenazine, prochlorperazine, thioridazine), were enhanced when a bacopa extract was given along with it. Until more is known, people taking medications from this family of drugs (called phenothiazines) should not take bacopa.

Explanation Required 

  • Vitamin C

    Taking phenothiazine drugs can stop menstruation in some women. Two women taking phenothiazines similar to perphenazine began menstruating following supplementation with 6 grams of vitamin C each day. Controlled studies are needed to determine whether vitamin C supplementation might benefit women specifically taking perphenazine who are experiencing menstrual changes. Some health practitioners recommend vitamin C supplementation to women who stop menstruating while taking perphenazine. Vitamin C might also enhance the effectiveness of neuroleptic drugs such as perphenazine in the treatment of schizophrenia. One uncontrolled study showed that 10 of 13 individuals experienced a reduction in disorganized thoughts, hallucinations, and suspicious thoughts when 8 grams of vitamin C was added to their daily drug therapy. Controlled studies are needed to show whether people taking perphenazine for schizophrenia might benefit from vitamin C supplementation.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
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.

PeaceHealth endeavors to provide comprehensive health care information, however some topics in this database describe services and procedures not offered by our providers or within our facilities because they do not comply with, nor are they condoned by, the ethics policies of our organization.