Which drug was most likely prescribed for the 44-year-old woman with poorly controlled simple partial seizures that was only partially effective with valproic acid?

Correct Answer: D

Rationale: Step 1: Identify the patient has poorly controlled simple partial seizures. Step 2: Valproic acid is partially effective. Step 3: Consider alternative options for drug-resistant partial seizures. Step 4: Perampanel is an FDA-approved treatment for partial-onset seizures in patients aged 12 and older. Step 5: Perampanel works by blocking glutamate receptors, reducing neuronal excitability. Therefore, it is the most appropriate choice for this patient. Other choices are not specifically indicated for partial seizures or have different mechanisms of action.

Correct Answer: C

Rationale: Step-by-step rationale for why choice C, Mesolimbic pathway, is correct: 1. The mesolimbic pathway is involved in the reward and pleasure system. 2. Dysfunction in this pathway can lead to psychotic symptoms like hallucinations. 3. Antipsychotic medications target this pathway to reduce psychotic symptoms. 4. The patient's symptoms of hearing voices suggest dysfunction in the mesolimbic pathway. Summary of why other choices are incorrect: A. Frontal cortex: Primarily involved in executive functions, not directly related to psychotic symptoms like hallucinations. B. Vestibular nuclei: Responsible for balance and spatial orientation, not related to psychotic symptoms. D. Striatum: Involved in motor control and procedural learning, not directly linked to hallucinations or psychotic symptoms.

Correct Answer: C

Rationale: The correct answer is C, the mesolimbic mesocortical pathway. Aripiprazole is an atypical antipsychotic that works by blocking dopamine receptors in this pathway, reducing dopaminergic transmission. This helps alleviate positive symptoms of schizophrenia like hallucinations and delusions. The other choices are incorrect because: A: Tuberoinfundibular pathway is involved in regulating prolactin secretion, not related to schizophrenia. B: Locus ceruleus is primarily involved in noradrenergic neurotransmission, not the main target for antipsychotics. D: N/A is not a valid answer and does not provide any relevant information.

Correct Answer: C

Rationale: The correct answer is C: Amitriptyline. The patient's symptoms suggest anticholinergic toxicity, which aligns with amitriptyline's side effects due to its strong anticholinergic properties. Amitriptyline can cause dry mouth, blurred vision, urinary retention, and confusion. Bupropion (A) is unlikely to cause these specific symptoms. Mirtazapine (B) is more sedating than anticholinergic. Paroxetine (D) is an SSRI and does not typically cause anticholinergic toxicity.

Correct Answer: A

Rationale: The correct answer is A: Blockade of M receptors. The enteric nervous system predominantly utilizes muscarinic receptors to regulate gastrointestinal motility. Blocking these receptors can lead to adverse effects such as constipation, as it disrupts normal peristalsis. Increased serotonergic activity (B) would typically enhance gastrointestinal motility. Activation of β receptors (C) would enhance smooth muscle relaxation, potentially improving motility. Increased adrenergic activity (D) could also enhance motility due to the role of adrenergic receptors in promoting smooth muscle contraction. However, the adverse effect described in the question is more likely to be caused by the blockade of M receptors, making choice A the correct answer.