Which of the following adverse effects is most likely to occur during the therapy?

Correct Answer: D

Rationale: The correct answer is D: Pancreatitis. During therapy, certain medications can cause pancreatitis due to their toxic effects on the pancreas. This can lead to inflammation of the pancreas, resulting in symptoms such as severe abdominal pain, nausea, and vomiting. Pancreatitis is a serious condition that requires immediate medical attention. Rationale: - A (Macrocytic anemia): This adverse effect is more commonly associated with deficiencies in vitamin B12 or folic acid, not typically caused by medications during therapy. - B (Hallucinations): Hallucinations are more likely to occur as a side effect of certain psychiatric medications or in cases of substance abuse, rather than during general therapy. - C (Liver cirrhosis): Liver cirrhosis is a long-term consequence of chronic liver damage, often due to alcohol abuse or viral hepatitis, not typically a direct adverse effect of therapy.

Correct Answer: A

Rationale: The correct answer is A: Carbamazepine. This is because carbamazepine is commonly used as an alternative to valproic acid due to its similar efficacy in treating certain types of seizures. Carbamazepine is also effective in treating bipolar disorder, which may be a reason for switching from valproic acid. Clonazepam (B) and phenytoin (C) are not appropriate substitutes for valproic acid as they have different mechanisms of action and are used for different types of seizures. Ethosuximide (D) is primarily used for absence seizures and would not be a suitable substitute for valproic acid in this case.

Correct Answer: A

Rationale: The correct answer is A: Carbamazepine. It is the most appropriate choice due to its efficacy in treating complex partial seizures. Carbamazepine is also less likely to worsen atrioventricular block compared to other antiepileptic drugs. Furthermore, it does not typically exacerbate nephrolithiasis. Phenytoin (B) can worsen atrioventricular block and does not specifically target complex partial seizures. Valproic acid (C) is contraindicated in patients with nephrolithiasis. Ethosuximide (D) is primarily used for absence seizures, not complex partial seizures.

Correct Answer: B

Rationale: The correct answer is B: Levodopa. Levodopa is a common medication used to treat Parkinson's disease. The symptoms described by the patient, such as facial grimacing, lip smacking, and rocking of the trunk, are characteristic of levodopa-induced dyskinesias, which can occur as a side effect of long-term levodopa therapy. Levodopa-induced dyskinesias usually develop after 1-2 hours of taking the medication, as seen in this case. Choice A: Selegiline is a selective MAO-B inhibitor and is less likely to cause the described adverse effects compared to levodopa. Choice C: Entacapone is a catechol-O-methyltransferase (COMT) inhibitor used in combination with levodopa, but it is not known to cause the specific dyskinesias described. Choice D: Amantadine is an antiviral agent with antiparkinsonian effects, but it is

Correct Answer: B

Rationale: The correct answer is B: Decreased acetylcholine release from cholinergic terminals. Acetylcholine release from cholinergic terminals contributes to the parasympathetic response, which can cause adverse effects such as bradycardia. By decreasing acetylcholine release, the parasympathetic response is reduced, leading to a more balanced autonomic control of the heart rate. Activation of cardiac dopamine receptors (choice A) and β receptors (choice C) would usually have positive effects on the heart, while blockade of cardiac M receptors (choice D) would exacerbate the adverse effects by blocking the already decreased parasympathetic response.