Neuroleptic induced parkinsonism

This code represents a form of secondary parkinsonism caused by the use of neuroleptic (antipsychotic) medications. Patients typically present with symptoms such as tremor, rigidity, bradykinesia, and postural instability, which develop after initiating or increasing the dose of an antipsychotic drug. These symptoms are a direct pharmacological effect of dopamine receptor blockade.

Assign this code when documentation clearly indicates parkinsonian symptoms are a direct adverse effect of neuroleptic medication use. This diagnosis is supported by a temporal relationship between drug exposure and symptom onset, and often by improvement upon dose reduction or discontinuation of the offending agent.

• Differentiate from idiopathic Parkinson's disease; this code is specifically for drug-induced parkinsonism.
• Do not code with G21.0 (Malignant neuroleptic syndrome) as per Excludes1 note, as these are distinct conditions.
• Ensure the medical record specifies the neuroleptic medication implicated to support the diagnosis.