Drug-induced chronic gout, right knee, without tophus

This code signifies chronic gout in the right knee that is specifically caused by a medication, without the presence of visible or palpable urate crystal deposits (tophi). It indicates a persistent inflammatory arthritis resulting from drug-induced hyperuricemia affecting the right knee joint.

Use this code when documentation explicitly states chronic gout of the right knee is drug-induced and no tophi are noted. This typically applies to patients with a history of medication use (e.g., diuretics, aspirin) leading to elevated uric acid levels and subsequent chronic gouty arthritis in the right knee.

• Ensure documentation clearly links the gout to a specific drug and specifies "chronic" and "right knee."
• Do not use this code if tophi are present; a different subcategory of M1A.26 will be required.
• Code the adverse effect of the drug separately using an appropriate T36-T50 code, if applicable, to fully capture the drug-induced nature.