Drug-induced tremor

This code identifies an involuntary, rhythmic muscle contraction and relaxation (tremor) that is a direct adverse effect of a prescribed or illicit medication. It signifies a neurological symptom caused by a pharmacological agent, rather than an idiopathic or primary neurological disorder.

Apply this code when documentation clearly links the onset or exacerbation of tremor to a specific drug. This typically includes cases where the tremor resolves or improves with drug discontinuation or dosage adjustment. Supporting documentation should identify the causative drug.

• Always code the adverse effect (tremor) first, followed by the external cause code for the drug (T36-T50 with 5th or 6th character indicating adverse effect).
• Distinguish from essential tremor (G20.00-G20.01) or other secondary tremors where a drug is not the direct cause.
• Ensure the medical record specifies the drug responsible for the tremor to support accurate external cause coding.