Hydroxychloroquine dosage

A woman with discoid lupus, controlled by hydroxychloroquine, rapidly relapsed when rifampicin was started. Disease control was regained when the hydroxychloroquine dosage was doubled. 

This seems to be the first and only report of this interaction, but what happened is consistent with the way rifampicin interacts with many other drugs. If rifampicin is added to hydroxychloroquine, the outcome should be well monitored. Be alert for the need to increase the hydroxychloroquine dosage. 

The indications for therapy with SBC-5-IMNs in DMARD-Refractory RA are ESR > 40 mm (ESR of knee OA very rarely exceeds 40 mm) and VAS > 4. Patients are considered to have DMARD-Refractory RA (DR-RA) if optimal dosages of single and combined oral DMARDs (corticosteroids, hydroxychloroquine, sulphasalazine, and MTX) have been used for 2 months without lowering of the ESR with 1 mm or more, with a decrease of the swollen and tender joint count of less than 1 and the VAS still above 10 (scale 0-100) at month 1 and 2 compared with baseline. 

Although antimalarials improve symptoms, there is no evidence that these compounds alter bony damage in rheumatoid arthritis at their usual dosages (up to 6.4 mg/kg/d for hydroxychloroquine or 200 mg/d for chloroquine). It usually takes 3-6 months to obtain a response. Antimalarials are often used in the treatment of the skin manifestations, serositis, and joint pains of systemic lupus erythematosus, and they have been used in Sjogren s syndrome. 

A 57-year-old man took prednisone 20-30 mg/day for 13 years for rheumatoid arthritis (45). He had been treated unsuccessfully with gold, azathioprine, hydroxychloroquine, and sulfasalazine tapering his glucocorticoid dosage had been unsuccessful. He developed worsening back pain in his thoracic spine and lateral... 

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. ... 

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