Hydroxychloroquine adverse effects

Hydroxychloroquine administration may result in irritability, nervousness, anorexia, nausea, vomiting, and diarrhea This drug also may have adverse effects on the eye, including blurred vision, comeal edema, halos around lights, and retinal damage. Hematologic effects, such as aplastic anemia and leukopenia, may also be seen. 

With the combination of traditional DMARDs complete remissions are obtained in 30% of early RA over a period of 5 years. These remissions last on average less than 10 months. After 5 years only half of the patients continue with MTX and less than 25% stay on other DMARDs. After 5 years non-compliance is mostly due to adverse effects and lack of efficacy of NSAIDs, hydroxychloroquine, sulfasalazine, prednisone, d-penicillamine, azafhio-prine, and gold salts. Only MTX retains some efficacy. With these therapeutic modalities joint erosions progress to permanent joint destruction, deformities and disability. 

The addition of hydroxychloroquine to sulfonylureas has been investigated in a placebo-controlled study in 125 adipose patients whose diabetes was not well enough controlled with a sulfonylurea alone (179). During the first six months HbAlc was significantly reduced by 1.02%. There were no significant differences in adverse effects, but those who took hydroxychloroquine had a greater incidence of minor corneal changes. 

Hydroxychloroquine (Plaquenil) is derived chemically from chloroquine and is similar to it in clinical use, mechanism of action, and adverse effects. Hydroxychloroquine does not have any distinct therapeutic advantages over chloroquine, but it may be substituted in certain individuals who do not respond well to chloroquine. 

The pharmacology of these drugs, which are also used in the treatment of malaria, is presented on p. 351. The mechanism of their anti-inflammatory activity is uncertain. Besides inhibiting nucleic acid synthesis, they are known to stabilize lysosomal membranes and trap free radicals. In treating inflammatory disorders, they are reserved for rheumatoid arthritis that has been unresponsive to the NSAIDs or else they are used in conjunction with an NSAID, which allows a lower dose of chloroquine or hydroxychloroquine to be administered. These drugs have been shown to slow progression of erosive bone lesions and may induce remission. They do cause serious adverse effects (see p. 351). 

CIMETIDINE CHLOROQUINE, HYDROXYCHLOROQUINE t efficacy and adverse effects of chloroquine Inhibition of metabolism and excretion Consider ranitidine as alternative or take cimetidine at least 2 hours after chloroquine... 

Recommendations for screening procedures for chloro-quine or hydroxychloroquine toxicity have been quite variable both in frequency of examination and in types of required tests at each visit. Although examination for sight-threatening adverse effects of these medications is critical, evidence, costs, and risk-to-benefit ratios necessitate a balance of all these fectors. 

Adverse effects. Hydroxychloroquine accumulates in many organs, including the eye where it can cause... 

As pointed out in Meyler s SED VIII, the adverse effects of amodiaquine are generaUy similar to those associated with hydroxychloroquine (see below). 

In general, the adverse effects produced by hydroxychloroquine are similar to those seen with chloroquine. 

Hydroxychloroquine (Plaquenil), like chloroquine, is a 4-aminoquinoline derivative used for the suppressive and acute treatment of malaria. It also has been used for rheumatoid arthritis and discoid and systemic lupus erythematosus. Hydroxychloroquine has not been proved to be more effective than chloroquine. Adverse reactions associated with its use are similar to those described for chloroquine. The drug should not be used in patients with psoriasis or porphyria, since it may exacerbate these conditions. 

Originally used in the treatment of malaria, the drugs chloroquine (Aralen) and hydroxychloroquine (Pla-quenil) have also been used to treat rheumatoid arthritis. In the past, these drugs have been used reluctantly because of the fear of retinal toxicity (see Adverse Side Effects ).25 There is now evidence, however, that these agents can be used safely, but they are only marginally effective when compared to other DMARDs. These drugs are therefore not usually the first choice, but they can be used in patients who cannot tolerate other DMARDs, or in combination with another DMARD (e.g., methotrexate) for more comprehensive treatment. 

Dosage and duration of therapy depend on patient response, tolerance of side effects, and development of retinal toxicity, which is a potentially irreversible adverse reaction associated with long-term therapy, especially with chloroquine. Current recommended doses of antimalarials in SLE are hydroxychloroquine 200-400 mg/day and chloroquine 250-500 mg/day. After 1 or 2 years of treatment, gradual tapering of dosage can be attempted. Some patients may require only one or two tablets per week to suppress cutaneous manifestations. ... 

---