Major
Established
Mô tả
Quetiapine, a D2 receptor antagonist, pharmacodynamically opposes levodopa's dopaminergic effect, worsening Parkinson's disease motor symptoms.
Cơ chế
Levodopa is converted to dopamine and acts on striatal D2 receptors to improve Parkinsonism; quetiapine blocks D2 receptors, directly countering this therapeutic effect.
Ý nghĩa lâm sàng
Significant worsening of motor function (rigidity, bradykinesia, tremor) is expected when typical or atypical antipsychotics (except clozapine and pimavanserin) are used in Parkinson's disease.
Xử trí
Avoid dopamine-blocking antipsychotics in Parkinson's disease; use clozapine or pimavanserin (low D2 affinity) for psychosis management.