Cardiotoxic effects of methamphetamine have been proposed in many investigations, but the risk of striated muscles involvement among methamphetamine abusers is unknown.

A case-control study has begun in our teaching hospital to examine the association between methamphetamine abuse and myopathy. The study population are adult clients who admit in the electrodiagnostic medicine clinic since January 2015 with complains of weakness. For each subject with myopathy, 2 controls without myopathy are randomly selected from the same population. Self-reported history of methamphetamine abuse is acceptable in both groups.

A total of 56 persons with myopathy and 112 controls have been identified, of whom 5 (9 percent) and 3 (3 percent) had history of methamphetamine abuse, respectively. Persons with history of methamphetamine abuse have about three times greater chance to develop myopathy (95% CI: 1.5–5.1) as compared with controls.

There is a misconception among some workers that some illicit drugs such as psycho stimulants can improve their ability to work. In contrast, this study demonstrates that due to harmful effect on the muscles, methamphetamine could diminish the ability to work in long time.

The author has not supplied his declaration of competing interest.