Prednisone compared to methylprednisolone in the polymyalgia rheumatica treatment

Glucocorticoids (GLs) are the sole therapeutic approach in polymyalgia rheumatica (PMR). An undefined proportion of patients respond only to very high doses of GLs and some seem to respond better to methylprednisolone (MPONE) than to prednisone (PN) or vice versa. Fifty-two PMR patients were randomized (ratio 1/1) to a fixed daily dose of PN (25 mg) or MPONE (20 mg), and the dose was tapered with a fixed scheme at the time of symptomatic relief. The clinical and biochemical assessments were obtained at fixed time points: 2 weeks, and 3, 6, 12 months. A clinical and biochemical remission of PMR was observed in 100 % of the patients on MPONE and in 89 % of the patients on PN. The mean time to achieve full remission after the first dose was significantly (p < 0.05) longer for PN (20.3 days) than for MPONE (15.2 days). This difference was mainly driven by 3 patients in whom the remission was achieved after 26-49 days. The mean levels of serum ACTH and cortisol were very similar in both treatment groups as the slope of their correlations for equivalent steroid doses. PN and MPONE have a similar therapeutic effect on suppression of the HPA axis in PMR patients. The results of this preliminary study suggest that a delayed response to PN may occur. Further studies are warranted in order to verify whether this might be related to variations in 11β-hydroxysteroid dehydrogenase activity.