Hydroxychloroquine is used for prevention or chemoprophylaxis of malaria caused by Plasmodium malariae, P. ovale, chloroquine-susceptible P. vivax, or chloroquine-susceptible P. falciparum and for treatment of uncomplicated malaria caused by P. malariae, P. ovale, chloroquine-susceptible P. vivax, and chloroquine-susceptible P. falciparum.
Chloroquine has historically been considered the drug of choice for prevention of malaria in travelers to areas where chloroquine-resistant P. falciparum malaria has not been reported and for treatment of malaria acquired in areas where chloroquine resistance has not been reported. Hydroxychloroquine may be used when chloroquine is unavailable and may be better tolerated than chloroquine. The fact that chloroquine-resistant P. falciparum has now been confirmed in all areas with P. falciparum malaria, except the Caribbean, Central America west of the Panama Canal, and some countries in the Middle East, should be considered when selecting an antimalarial for prevention or treatment of malaria. Chloroquine-resistant P. falciparum also are resistant to hydroxychloroquine.
Because hydroxychloroquine is active only against the asexual erythrocytic forms of Plasmodium (not exoerythrocytic stages), the drug cannot prevent delayed primary attacks or relapse of P. ovale or P. vivax malaria and cannot provide a radical cure in malaria caused by these species. Therefore, terminal prophylaxis with a 14-day regimen of primaquine phosphate may be indicated in addition to hydroxychloroquine prophylaxis if travelers were exposed in areas where P. ovale or P. vivax is endemic and a 14-day regimen of primaquine phosphate also is indicated in conjunction with hydroxychloroquine for treatment of P. ovale or P. vivax malaria.
Patients with severe malaria require aggressive antimalarial treatment with a parenteral regimen of IV quinidine gluconate in conjunction with doxycycline, tetracycline, or clindamycin initiated as soon as possible after the diagnosis.
Information on the risk of malaria transmission in specific countries, information on mosquito avoidance measures, recommendations regarding whether chemoprophylaxis of malaria is indicated, and information on the choice of antimalarials for prevention of malaria are available from the US Centers for Disease Control and Prevention (CDC) at http://wwwnc.cdc.gov/travel and http://www.cdc.gov/malaria.
Assistance with diagnosis or treatment of malaria is available by contacting the CDC Malaria Hotline at 770-488-7788 or 855-856-4713 from 9:00 a.m. to 5:00 p.m. Eastern Standard Time or the CDC Emergency Operation Center at 770-488-7100 after hours and on weekends and holidays.
Hydroxychloroquine is used in the treatment of rheumatoid arthritis. Hydroxychloroquine is one of several disease-modifying antirheumatic drugs (DMARDs) that can be used when DMARD therapy is appropriate. If 4-aminoquinoline derivatives are used for prolonged periods in the treatment of rheumatoid arthritis, the risk of severe and sometimes irreversible toxicity should be considered.
Hydroxychloroquine is used as an adjunct to topical corticosteroid therapy in the treatment of discoid lupus erythematosus and as an adjunct to systemic corticosteroids and/or salicylate therapy in the treatment of systemic lupus erythematosus. Hydroxychloroquine therapy may lead to the regression of skin lesions of discoid or systemic lupus erythematosus and may also have a beneficial effect in patients with systemic lupus erythematosus in whom arthritis is a prominent feature. If 4-aminoquinoline derivatives are used for prolonged periods in the treatment of lupus erythematosus, the risk of serious and sometimes irreversible toxicity should be considered.
Although doxycycline usually is the drug of choice for the treatment of acute Q fever caused by Coxiella burnetii, a regimen of doxycycline and hydroxychloroquine is recommended for the treatment of Q fever endocarditis.
In a limited study in patients with confirmed C. burnetii infection and chronic endocarditis, a regimen of doxycycline and hydroxychloroquine was associated with a lower relapse rate than a regimen of doxycycline and ofloxacin. Although both regimens require long-term therapy, the mean duration of therapy for cured patients was 55 months for those who received the doxycycline and quinolone regimen compared with 31 months for those who received the doxycycline and hydroxychloroquine regimen. Prolonged therapy (at least 18 months) with the doxycycline and hydroxychloroquine regimen is necessary to prevent relapse. The CDC recommends a 2- to 3-week regimen of doxycycline for the treatment of acute Q fever, a 1-year regimen of doxycycline and hydroxychloroquine for the treatment of acute Q fever in patients with preexisting valvular heart disease (to prevent progression of acute disease to endocarditis), and a 1.5- to 3-year regimen of doxycycline and hydroxychloroquine for the treatment of chronic Q fever.
Porphyria Cutanea Tarda and Polymorphous Light Eruptions
Hydroxychloroquine has been used with some success in the treatment of porphyria cutanea tarda.
Hydroxychloroquine has been effective in some cases when used in the treatment of polymorphous light eruptions.