Conventional synthetic disease-modifying antirheumatic drugs for severe oligoarticular JIA
The approach to managing oligoarticular juvenile idiopathic arthritis (JIA), and the role of conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) in it, is described in management of oligoarticular JIA. Conventional synthetic disease-modifying antirheumatic drugs are used by specialists to induce and maintain remission of oligoarthritis in patients whose disease has not adequately responded to treatment with an intra-articular corticosteroid (eg have frequent relapses) or who have developed extended oligoarticular disease (polyarthritis after 6 months).
Methotrexate is the preferred csDMARD for most patients with oligoarticular JIA and has the advantage of treating chronic uveitis, if present. Oral bioavailability of methotrexate plateaus above 15 mg; subcutaneous administration may be considered if doses higher than 15 mg are ineffective and may also have the benefit of reducing methotrexate-induced nausea. The usual paediatric dosage of methotrexate is:
1methotrexate 10 to 20 mg/m2 up to 25 mg orally, on one specified day once weekly1 methotrexate methotrexate methotrexate
OR
1methotrexate 10 to 20 mg/m2 up to 25 mg subcutaneously, on one specified day once weekly methotrexate methotrexate methotrexate
PLUS with either of the above
folic acid 5 mg orally, weekly (not on the same day as methotrexate)2. folic acid folic acid folic acid
Leflunomide has been demonstrated to have similar efficacy to methotrexate and is used as an alternative in patients who do not tolerate methotrexate. The usual paediatric dosage of leflunomide is:
leflunomide leflunomide leflunomide leflunomide
child less than 20 kg: 10 mg orally, on alternate days
child 20 to 40 kg: 10 mg orally, daily
child more than 40 kg: 20 mg orally, daily.
Sulfasalazine has a limited role in the treatment of patients with extended oligoarthritis (polyarthritis after 6 months). The usual paediatric dosage of sulfasalazine is:
sulfasalazine 5 mg/kg up to 500 mg orally, twice daily, increasing over 2 to 4 weeks to 15 to 20 mg/kg up to 1000 mg orally, twice daily. sulfasalazine sulfasalazine sulfasalazine
Hydroxychloroquine has been demonstrated not to have the same efficacy as the csDMARDs recommended above, but is sometimes used in children and adolescents with mild presentations, or in combination with another csDMARD. The usual paediatric dosage of hydroxychloroquine is:
hydroxychloroquine 3 to 5 mg/kg up to 400 mg orally, daily. hydroxychloroquine hydroxychloroquine hydroxychloroquine
The specialist will determine the appropriate approach to monitoring, screening for infection, and vaccination based on the adverse effect profile of the drug and patient factors (eg disease activity, comorbidities). See also Principles of immunomodulatory drug use.