Match each clinical presentation following the initiation of antipsychotic therapy (left) with the underlying receptor mechanism or affected neuroanatomical pathway (right).
- A patient experiences a significant reduction in auditory hallucinations and persecutory delusions.Dopamine D2 receptor antagonism in the mesolimbic tract
- A patient develops bilateral breast enlargement and a milky nipple discharge, accompanied by the cessation of menses.Dopamine D2 receptor antagonism in the tuberoinfundibular tract
- A patient develops a sustained, painful contraction of the neck muscles (torticollis) shortly after receiving an intramuscular injection.Dopamine D2 receptor antagonism in the nigrostriatal tract
- A patient experiences sudden dizziness, lightheadedness, and a drop in blood pressure immediately upon standing from a seated position.Alpha-1 adrenergic receptor antagonism
- A patient reports severe dry mouth, new-onset constipation, and blurred vision, with a physical exam showing resting tachycardia.Muscarinic M1 cholinergic receptor antagonism
Answer
The reduction in hallucinations matches mesolimbic D2 antagonism; galactorrhea/amenorrhea matches tuberoinfundibular D2 antagonism; acute dystonia matches nigrostriatal D2 antagonism; orthostatic hypotension matches alpha-1 adrenergic antagonism; and anticholinergic effects match muscarinic M1 antagonism.
Each clinical presentation is a direct consequence of receptor blockade by antipsychotic medications. Mesolimbic D2 antagonism controls positive symptoms. Tuberoinfundibular D2 antagonism causes hyperprolactinemia. Nigrostriatal D2 antagonism causes acute extrapyramidal symptoms. Alpha-1 antagonism causes orthostatic hypotension. Muscarinic antagonism causes anticholinergic effects.
Step-by-Step Solution
Key Concept
Antipsychotic medications exert their primary therapeutic effects and cause distinct adverse side effects through the blockade of various receptors (D2, alpha-1, M1) across different neuroanatomical pathways.