azibirdAgree, most likely polymyositis. Whether this or statin myopathy the answer would be the same. I though Lambert-Eaton and picked myoneural junction, however DTRs would be decreased in this case and I don't think there would be tenderness either.+
Older patient on a statin drug who presents with muscle tenderness and objective muscle weakness, most consistent with a statin myopathy
Key idea: Important causes of a myopathy on NBME exam include glucocorticoids/Cushingโs, inflammatory myopathies (polymyositis, dermatomyositis), statin-induced myopathy and hypothyroid myopathy
ysegalHe has been treated with statin for 4 years. If he had statin induced myopathy, it would havee had to happen either in the begining or after a dose change+5
azibirdIt seems very unlikely that he would develop statin-associated myopathy after 4 years of treatment. If so, this would be at the extreme range of documented time to myopathy and I don't see why they would test it like that.
The onset of muscle symptoms is usually within weeks to months after the initiation of statin therapy but may occur at any time during treatment.
https://www.uptodate.com/contents/statin-muscle-related-adverse-events#H3
"Of 44 patients for whom data were available, the mean duration of statin therapy before symptom onset was 6.3 (9.8) months (range, 0.25-48.0 months) (Table 4). More specifically, approximately one third of the patients (n = 17) noted muscle pain within 1 month and another one third (n = 16) within 6 months of beginning statin therapy."
https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/7668+
submitted by โseagull(1933)
Polymyositis - Proximal muscle weakness, tenderness, Creatine kinase elevated. Normal DTR, Anti Jo antibodies.