Final answer:
Orthostatic hypotension can occur due to the adrenergic effects of antipsychotic drugs. These drugs antagonize adrenergic receptors, which disrupt the sympathetic reflex responsible for maintaining blood pressure when standing up.
Step-by-step explanation:
Orthostatic hypotension can occur due to the adrenergic effects of antipsychotic drugs. These drugs, such as risperidone (Risperdal), antagonize adrenergic receptors, which can disrupt the sympathetic reflex responsible for maintaining blood pressure when standing up. When the sympathetic system cannot increase cardiac output, blood pressure into the brain decreases, resulting in orthostatic hypotension.