ABCN Pharmacology Fundamentals 3

Question 1

Which benzodiazepine is preferred for elderly patients because it does not undergo hepatic oxidation and lacks active metabolites?

Accepted Answer

Lorazepam

Answer

Lorazepam undergoes direct glucuronidation (the LOT rule: Lorazepam, Oxazepam, Temazepam) and is safer in elderly patients with impaired hepatic oxidative metabolism.

Question 2

A patient on valproate develops tremor, weight gain, and elevated ammonia levels without liver disease. The elevated ammonia is best explained by valproate's effect on:

Accepted Answer

Inhibition of urea cycle enzymes via carnitine depletion

Answer

Valproate depletes carnitine and inhibits urea cycle function, leading to hyperammonemia independent of hepatotoxicity.

Question 3

Which atypical antipsychotic is most associated with metabolic syndrome, weight gain, and new-onset diabetes?

Accepted Answer

Clozapine

Answer

Clozapine has the highest risk of metabolic syndrome among antipsychotics due to potent H1, muscarinic, and 5-HT2C antagonism.

Question 4

A neuropsychologist is informed that a patient's phenytoin level is within normal range but the patient has symptoms of toxicity. Which condition would most likely explain this discrepancy?

Accepted Answer

Hypoalbuminemia shifting the free fraction upward

Answer

Phenytoin is ~90% protein-bound; hypoalbuminemia increases the free (active) fraction without changing total measured levels, causing toxicity at 'normal' concentrations.

Question 5

Memantine's mechanism of action in Alzheimer's disease involves:

Accepted Answer

Non-competitive NMDA receptor antagonism

Answer

Memantine blocks NMDA receptors non-competitively, reducing excitotoxic glutamate activity implicated in Alzheimer's neurodegeneration.

(ABCN) American Board of Clinical Neuropsychology Practice Test

(ABCN) American Board of Clinical Neuropsychology Practice Test

ABCN Pharmacology Fundamentals 3