Time of day of prednisolone administration in rheumatoid arthritis.

Twelve patients with rheumatoid arthritis took low dosage prednisolone, mean 5.6 mg daily, at either 0800 h, 1300 h or 2300 h in a double-blind within-patient controlled trial. Each patient was studied on each of the 3 regimens to assess control of symptoms and side effects and also to examine circadian rhythms in signs and symptoms. For several days during each drug regimen patients collected urine at each micturition and self-assessed their signs and symptoms. Circadian rhythms of finger joint swelling and of grip strength were determined, and were similar on all regimens, with morning peaks of symptoms and signs. Subjective and objective assessments showed no differences in effectiveness between the 3 times of administration of prednisolone. Urinary excretion patterns were similar to those observed in untreated people. The quantity and circadian pattern of 11-hydroxycorticosteroids excreted were similar to those in healthy patients, providing no evidence of adrenal cortical suppression at the dose levels studied, even when this dose was taken in the evening. A single morning dose of prednisolone appears in many patients to be as effective as a single evening dose or divided doses. It is therefore reasonable to initiate therapy with a morning-only regimen, because adrenopituitary suppression should be minimised.