Toxic myopathy

This code represents muscle weakness or damage caused by exposure to toxic substances. The myopathy can manifest as acute or chronic muscle pain, cramps, fatigue, or paralysis, resulting from direct toxicity to muscle fibers or secondary effects on the neuromuscular junction.

Use this code when documentation clearly links a patient's myopathy to a specific toxic agent, such as certain medications, illicit drugs, environmental toxins, or industrial chemicals. Supporting documentation should include a history of exposure, clinical findings consistent with myopathy, and often laboratory evidence or biopsy results ruling out other causes.

• Always attempt to identify and code the specific toxic agent (E-code) in addition to the myopathy.
• Differentiate from other forms of myopathy (e.g., inflammatory, metabolic, hereditary) which have distinct codes.
• Ensure the documentation explicitly states the toxic etiology; "myopathy" alone is insufficient.