RHEUMATOID ARTHRITIS, ADULT OVER 18 YEARS, INITIALLY 100 MG ONCE DAILY FOR 3 DAYS THEN MAINTENANCE, 10-20 MG ONCE DAILY. PSORIATIC ARTHRITIS, ADULT OVER 18 YEARS, INITIALLY 100 MG ONCE DAILY FOR 3 DAYS THEN MAINTENANCE, 20 MG ONCE DAILY.CHILDREN UNDER 12 YRS NOT RECOMMENDED.