Which of the following medications is most likely associated with sexual dysfunction when treated with antipsychotics?

The association of sexual dysfunction with antipsychotic medications, particularly haloperidol, is well established. Haloperidol is a typical antipsychotic that primarily acts as a dopamine antagonist. By blocking dopamine receptors, particularly D2 receptors in the brain, haloperidol can lead to several side effects, including sexual dysfunction. This occurs because dopamine plays a crucial role in the sexual response cycle; its inhibition can result in reduced libido, erectile dysfunction, and anorgasmia.

In comparison, fluoxetine and citalopram are selective serotonin reuptake inhibitors (SSRIs). While these medications are also linked to sexual side effects, they do not have the same degree of association with sexual dysfunction as haloperidol. Clozapine, which is an atypical antipsychotic, tends to have a different side effect profile and is generally associated with fewer sexual side effects relative to typical antipsychotics. Thus, haloperidol stands out in this context as the medication most likely to cause sexual dysfunction due to its mechanism of action and the nature of its receptor interactions.