Drug Interactions between Doxy-Caps and Plaquenil

You may want to limit your consumption of grapefruit or grapefruit juice during treatment with hydroxychloroquine. Grapefruit juice can significantly increase the blood levels and effects of hydroxychloroquine, which may result in an irregular heart rate or other conduction disturbances. Hydroxychloroquine should also be taken with food or milk to reduce the incidence of stomach upset. Talk to your doctor if you have any questions or concerns. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or heart palpitations during treatment with hydroxychloroquine. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Consumer information for this interaction is not currently available.

GENERALLY AVOID: The oral bioavailability of quinolone and tetracycline antibiotics may be reduced by concurrent administration of preparations containing polyvalent cations such as aluminum, calcium, iron, magnesium, and zinc. Therapeutic failure may result. The proposed mechanism is chelation of quinolone and tetracycline antibiotics by di- and trivalent cations, forming an insoluble complex that is poorly absorbed from the gastrointestinal tract. Reduced gastrointestinal absorption of the cations should also be considered.

MANAGEMENT: Concomitant administration of oral quinolone and tetracycline antibiotics with preparations containing aluminum, calcium, iron, magnesium, and/or zinc salts should generally be avoided. Otherwise, the times of administration should be staggered by as much as possible to minimize the potential for interaction. Quinolones should typically be dosed either 2 to 4 hours before or 4 to 6 hours after polyvalent cation preparations, depending on the quinolone and formulation. Likewise, tetracyclines and polyvalent cation preparations should typically be administered 2 to 4 hours apart. The prescribing information for the antibiotic should be consulted for more specific dosing recommendations.

Information for this minor interaction is available on the professional version.

The recommended maximum number of medicines in the 'antimalarials' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'antimalarials' category:

• Doxy-Caps (doxycycline)
• Plaquenil (hydroxychloroquine)

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.