Finasteride-induced myalgia and HyperCKemia.
BACKGROUND
Finasteride is an antiandrogen, inhibits type II 5-alpha reductase (enzyme that converts testosterone to more potent form dihydrotestosterone), and is commonly used in the treatment of benign prostatic hyperplasia and male frontal baldness; however, it is not free from side effects, which include sexual dysfunction and, rarely, myopathy. We report a case of finasteride-associated myalgia and hyperCKemia and review similar cases reported in the literature.


METHODS
A 30-year-old man who had been taking finasteride 5 mg/d for 10 years to treat frontal baldness developed diffuse muscle aches associated with elevated creatine kinase level to 10,117 IU/L with neither weakness nor pigmenturia. His symptoms resolved and his creatine kinase level dropped down to 256 IU/L 3 weeks after finasteride discontinuation.


CONCLUSIONS
Reversible myalgia associated with significant hyperCKemia is a possible adverse reaction of finasteride therapy.
Al-Harbi
Talal M
TM
Neurology Division, Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Kagan
Jennifer
J
Tarnopolsky
Mark A
MA
D000328:Adult; D000505:Alopecia / Q000188:drug therapy; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D052283:Creatine Kinase, MM Form / Q000032:analysis / Q000097:blood*; D004791:Enzyme Inhibitors / Q000009:adverse effects; D018120:Finasteride / Q000009:adverse effects*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D009135:Muscular Diseases / Q000139:chemically induced* / Q000378:metabolism / Q000503:physiopathology; D010146:Pain / Q000139:chemically induced* / Q000378:metabolism / Q000503:physiopathology; D011237:Predictive Value of Tests; D013739:Testosterone / Q000009:adverse effects; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
D015415:Biomarkers; D004791:Enzyme Inhibitors; D013739:Testosterone; D018120:Finasteride; D052283:Creatine Kinase, MM Form