Acetylsalicylic acid and juvenile rheumatoid Arthritis. Effect of dosage interval on the serum salicylic acid level.

A 2-dose regimen and a 3-dose regimen, both with the same daily dose of acetylsalicylic acid, were compared in 8 patients with juvenile rheumatoid arthritis. The regimens were given according to a cross-over design. The serum salicylic acid levels over 24 hours were studied at the end of each treatment period. As expected somewhat greater fluctuations in the salicylic acid levels were observed with the 2-dose than with the 3-dose regimen. However, therapeutically effective serum levels were observed for most of the 24 hour period with both regimens. It is suggested that a 2-dose regimen has advantage with regard to simplicity and compliance. The pharmacokinetic findings indicate that a 2-dose regimen may be useful in patients with juvenile rheumatoid arthritis.