title: Relationship between serum creatine kinase level and corticosteroid therapy in polymyositis-dermatomyositis.
abstract: Few guidelines exist for the use of corticosteroid therapy in polymyositis-dermatomyositis (PM-DM). We retrospectively examined the relationship between serum creatine kinase (CK), muscle strength and the dosage and method of administration of prednisone in 30 patients with PM-DM observed monthly for a minimum of one year. Forty-two corticosteroid treated episodes of proximal muscle weakness associated with CK elevations formed the final study group. Each patient course was designated as having a good or poor biochemical and clinical outcome based on predetermined criteria. Adherence to 3 principles predicted a favorable biochemical and clinical outcome in the treatment of myositis: (1) administration of an adequate initial (loading) corticosteroid dose; (2) continuation of the initial dose until or after the time that the serum CK had become normal; and (3) a slow corticosteroid taper rate. Achievement of a CK within the low normal range predicted a prolonged biochemical remission, and a rise of CK within the normal range signalled a subsequent biochemical and clinical relapse. Tapering the corticosteroid dose when the CK was elevated frequently resulted in a further increase in CK. These observations allowed us to develop practical guidelines for the management of PM-DM.
authors.affiliation: Department of Medicine, University of Pittsburgh School of Medicine, PA 15261.
authors.forename: C V
authors.initials: CV
authors.lastname: Oddis
authors.forename: T A
authors.initials: TA
authors.lastname: Medsger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003402:Creatine Kinase / Q000097:blood*; D003882:Dermatomyositis / Q000188:drug therapy* / Q000201:enzymology / Q000503:physiopathology; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000503:physiopathology; D009220:Myositis / Q000188:drug therapy* / Q000201:enzymology / Q000503:physiopathology; D011241:Prednisone / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D012189:Retrospective Studies
chemical_list: D003402:Creatine Kinase; D011241:Prednisone