Drug-induced myopathy

This code represents muscle weakness and damage (myopathy) that is directly caused by an adverse reaction to a medication. It signifies a toxic effect of a drug on muscle tissue, leading to symptoms such as muscle pain, tenderness, and elevated muscle enzymes.

Use this code when documentation clearly links a patient's myopathy to a specific drug, whether prescribed, over-the-counter, or illicit. This diagnosis is supported by a temporal relationship between drug exposure and symptom onset, and often by the resolution of symptoms upon drug discontinuation.

• Always code the adverse effect of the drug first (T36-T50 with 5th or 6th character 5 for adverse effect in therapeutic use).
• Ensure the medical record specifies the drug responsible for the myopathy.
• Distinguish from other forms of myopathy (e.g., inflammatory, metabolic) where drug causation is not established.