Internal Medicine

0521779407-17 CUNY1086/Karliner 0 521 77940 7 June 13, 2007 7:57

1192 Polymyositis and Related Disorders

General Measures

■Check baseline labs used to screen side effects of meds

■CXR & pulmonary function tests if concerned for interstitial lung

disease

■Swallowing study if there is dysphagia or hoarseness

■Physical therapy to prevent contracture & maintain strength of unaf-

fected muscles

■Screen for malignancy as appropriate for pt’s age & gender

specific therapy

Treatment Options

■High-dose oral prednisone

■In severe disease, add methotrexate or azathioprine

■In DM, topical steroids or hydroxychloroquine may help rash but

not muscle weakness

■In refractory cases, IVIg may lead to improvement

■Cylcosporine, tacrolimus & alkylating agents such as cyclophos-

phamide & chlorambucil have also been reported as effective

■Case reports also describe the efficacy of tumor necrosis factor

inhibitors such as infliximab

Side Effects & Contraindications

■Prednisone: hypertension, glucose intolerance, sodium retention,

hypokalemia, rash, cushingoid appearance, osteoporosis, aseptic

necrosis, cataracts, infection

■Methotrexate: mucositis, GI distress, cirrhosis, bone marrow

depression, pneumonitis, pseudolymphoma, infection. Avoid use

w/alcohol use or liver or renal dysfunction.

■Azathioprine: GI distress, bone marrow depression, serious infec-

tion. Increased risk of neoplasia if previously used alkylating agent.

Avoid concomitant use of allopurinol.

follow-up

■See every 4 to 6 weeks, checking muscle strength & CPK & for poten-

tial drug toxicities. Frequency can be decreased if remission is seen.

■Meds are gradually tapered over a 6-month period once remission

has been achieved for 6 to 12 weeks.

complications & prognosis

■Refractory disease may result in severe muscle weakness w/ atrophy,

joint contractures, aspiration pneumonia