Which of the following drugs most likely caused the patient's signs and symptoms?

Correct Answer: B

Rationale: The correct answer is B: Lamotrigine. Lamotrigine is known to cause a rare but serious skin reaction called Stevens-Johnson Syndrome (SJS). The patient's signs and symptoms are consistent with SJS, which include fever, sore throat, skin rash, and blistering. Gabapentin (A), Clonazepam (C), and Phenytoin (D) are not commonly associated with SJS. Summary: A, C, and D are incorrect as they are not known to cause SJS, unlike Lamotrigine which is a known culprit for this severe skin reaction.

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: B

Rationale: Correct Answer: B (Carbidopa) Rationale: 1. Carbidopa is a dopa decarboxylase inhibitor commonly used with levodopa to treat Parkinson's disease. 2. Haloperidol, an antipsychotic, can worsen Parkinson's symptoms like cogwheel rigidity. 3. Combining haloperidol with carbidopa can lead to a drug interaction and exacerbate Parkinson's symptoms. 4. Amantadine, pramipexole, and benztropine are commonly used to manage Parkinson's symptoms and would not be contraindicated. Summary: A: Amantadine - Not contraindicated, can be used to manage Parkinson's symptoms. C: Pramipexole - Not contraindicated, can be used to manage Parkinson's symptoms. D: Benztropine - Not contraindicated, can be used to manage Parkinson's symptoms.

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.