Fexofenadine-Pseudoephedrine

Drug Information

Common brand names:

Allegra-D 12 Hour, Allegra-D 24 Hour

Summary of Interactions with Vitamins, Herbs, & Foods

Types of interactions:BeneficialAdverseCheck

Replenish Depleted Nutrients

  • none

Reduce Side Effects

  • none

Support Medicine

  • none

Reduces Effectiveness

  • none

Potential Negative Interaction

  • Pomegranate juice has been shown to inhibit the same enzyme that is inhibited by grapefruit juice. The degree of inhibition is about the same for each of these juices. Therefore, it would be reasonable to expect that pomegranate juice might interact with fexofenadine in the same way that grapefruit juice does.

  • Pomegranate juice has been shown to inhibit the same enzyme that is inhibited by grapefruit juice. The degree of inhibition is about the same for each of these juices. Therefore, it would be reasonable to expect that pomegranate juice might interact with fexofenadine in the same way that grapefruit juice does.

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

Explanation Required

  • St. John’s Wort

    In a study of healthy volunteers, administration of 900 mg of St. John's wort one hour prior to fexofenadine resulted in a significant increase in blood levels of fexofenadine, compared with the blood levels after taking fexofenadine alone. On the other hand, long-term administration of St. John's wort (300 mg three times per day for two weeks) did not alter blood levels of fexofenadine. Until more is known, St. John's wort should not be combined with fexofenadine, except under the supervision of a doctor.

  • Fo-Ti

    Many drugs used in the treatment of high blood pressure cause relaxation or dilation of blood vessels. Laboratory studies show that emodin, a compound in Polygonum multiflorum, also relaxes blood vessels. However, animal studies reveal that phenylephrine blocks the action of emodin. Controlled studies are needed to determine whether Polygonum multiflorum helps people with high blood pressure and whether phenylephrine blocks its beneficial effects.

    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.

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