Hydroxychloroquine

Also indexed as: Plaquenil®

Hydroxychloroquine is used to prevent and treat acute attacks of malaria and to treat both acute and chronic rheumatoid arthritis and lupus. It is in a class of drugs known as antimalarials.

Summary of Interactions with Vitamins, Herbs, and Foods
(for details about the summarized interactions, read the full article)

Beneficial May be Beneficial: Depletion or interference—The medication may deplete or interfere with the absorption or function of the nutrient. Taking these nutrients may help replenish them.

Calcium*

Vitamin D*
Beneficial May be Beneficial: Supportive interaction—Taking these supplements may support or otherwise help your medication work better.

Vitamin B6*
Avoid Avoid: Reduced drug absorption/bioavailability—Avoid these supplements when taking this medication since the supplement may decrease the absorption and/or activity of the medication in the body.

Magnesium*
Side effect reduction/prevention

None known
Adverse interaction

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

Calcium and Vitamin D
Normally, the active form of vitamin D increases the absorption of calcium into the body. In a 45-year-old woman with sarcoidosis, taking hydroxychloroquine blocked the formation of active vitamin D, which helped normalize elevated blood levels of calcium in this case.1 Whether hydroxychloroquine has this effect in people who don’t have sarcoidosis or elevated calcium is unknown. Until controlled research explores this interaction more thoroughly, people taking hydroxychloroquine might consider having their vitamin D and/or calcium status monitored by a health practitioner.

Vitamin B6
An individual who took hydroxychloroquine and vitamin B6 together for nine years experienced a complete disappearance of skin nodules caused by rheumatoid arthritis.2 Controlled study is needed to determine whether taking vitamin B6 with or without hydroxychloroquine might help eliminate nodules in people with rheumatoid arthritis.

Magnesium
Magnesium supplementation may reduce blood levels of chloroquine, a compound similar to hydroxychloroquine, and decrease its effectiveness.3 Until more is known, people taking hydroxychloroquine for arthritis who are also using magnesium supplements and are not experiencing relief might try avoiding the supplements or taking them at separate times.

Interaction with Foods and Other Compounds –––

Hydroxychloroquine should be taken with food to avoid possible stomach upset.4

References

1. Barre PE, Gascon-Barre M, Meakins JL, Goltzman D. Hydroxychloroquine treatment of hypercalcemia in a patient with sarcoidosis undergoing hemodialysis. Am J Med 1987;82:1259–62.

2. McCarty DJ. Complete reversal of rheumatoid nodulosis. J Rheumatology 1991;18:736–7.

3. Olin BR, ed. Anti-infectives, Antimalarial Preparations, 4-Aminoquinoline Compounds. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, 1993, 1913–6.

4. Olin BR, ed. Anti-infectives, Antimalarial Preparations, 4-Aminoquinoline Compounds. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, 1993, 1913–6.