Which of the following muscle relaxants would be contraindicated in a patient with Tubocurarine deficiency of plasma cholinesterase?

Correct Answer: A

Rationale: The correct answer is A: Tubocurarine. Tubocurarine is a non-depolarizing muscle relaxant that works by blocking the action of acetylcholine at the neuromuscular junction. In a patient with Tubocurarine deficiency of plasma cholinesterase, using Tubocurarine as a muscle relaxant would be contraindicated because it would exacerbate the deficiency and lead to prolonged effects. Summary of other choices: B: Cisatracurium - Not contraindicated in a patient with Tubocurarine deficiency of plasma cholinesterase. C: Baclofen - Acts on spinal cord neurons, not related to neuromuscular junction function. D: Mivacurium - A short-acting non-depolarizing muscle relaxant, not contraindicated in this scenario.

Correct Answer: C

Rationale: The correct answer is C: Propofol induction. Cisatracurium is preferred over tubocurarine for patients undergoing propofol induction due to its faster onset and shorter duration of action, aligning with propofol's rapid onset and short duration. This minimizes the risk of prolonged muscle paralysis and respiratory depression. Liver insufficiency (A) and renal insufficiency (D) would not affect the choice between cisatracurium and tubocurarine. Advanced age (B) alone is not a primary factor for choosing cisatracurium over tubocurarine.

Correct Answer: B

Rationale: The correct answer is B: Carbamazepine. The patient most likely took Carbamazepine because it is commonly used to treat trigeminal neuralgia, a condition characterized by severe facial pain. Valproic acid is used for seizures and mood disorders, not typically for facial pain. Lamotrigine is primarily used for seizures and bipolar disorder. Ethosuximide is used for absence seizures, not trigeminal neuralgia. Therefore, based on the patient's symptoms and common drug indications, Carbamazepine is the most likely drug taken.

Correct Answer: A

Rationale: Valproic acid is the correct answer because it exhibits dose-dependent elimination kinetics, meaning its clearance rate changes with dosage. In patients with epilepsy, maintaining steady drug levels is crucial for seizure control. Valproic acid's dose-dependent elimination allows for more predictable drug levels at higher doses. Lamotrigine, phenytoin, and topiramate do not exhibit this characteristic. Lamotrigine has time-dependent kinetics, phenytoin follows Michaelis-Menten kinetics, and topiramate has linear kinetics. Therefore, Valproic acid is the most likely drug taken by the patient.

Correct Answer: B

Rationale: The correct answer is B: Topiramate. For a boy, topiramate is most appropriate due to its efficacy in treating various types of seizures, including absence seizures common in children. It has a favorable side effect profile and can be used as monotherapy. Carbamazepine (A) is not ideal for absence seizures, Diazepam (C) is more for acute seizure management, and Ethosuximide (D) is specifically for absence seizures and may not cover other seizure types.