Final answer:
The first-line treatment for Parkinson's disease and prominent psychosis is the use of antipsychotic medications that block dopamine receptors and decrease dopamine neurotransmission in the brain.
Step-by-step explanation:
The first-line treatment for Parkinson's disease and prominent psychosis is the use of antipsychotic medications. Antipsychotics, also known as neuroleptics, are a class of psychotropic medication primarily used to manage psychosis. These medications work by blocking dopamine receptors and decreasing dopamine neurotransmission in the brain, which can help alleviate the symptoms of psychosis in Parkinson's disease patients.