Pharmacology Central Nervous System Agents 2

Question 1

A patient taking an MAO inhibitor eats aged cheese and develops a hypertensive crisis. What interaction caused this?

Accepted Answer

Tyramine accumulation due to inhibited MAO-A breakdown

Answer

MAO-A normally metabolizes dietary tyramine; inhibiting it causes tyramine accumulation, massive norepinephrine release, and hypertensive crisis.

Question 2

Which benzodiazepine is preferred for treating acute alcohol withdrawal seizures due to its long half-life and self-tapering effect?

Accepted Answer

Diazepam

Answer

Diazepam has active metabolites with very long half-lives, providing a gradual self-tapering effect ideal for alcohol withdrawal management.

Question 3

A patient on lithium presents with coarse tremor, confusion, and ataxia. Serum lithium is 2.8 mEq/L. What is the priority intervention?

Accepted Answer

Discontinue lithium and initiate hemodialysis

Answer

Lithium toxicity above 2.5 mEq/L with neurological symptoms requires immediate discontinuation and hemodialysis to rapidly clear lithium.

Question 4

Which mechanism best explains how levodopa reduces Parkinson's symptoms?

Accepted Answer

Crosses the blood-brain barrier and is converted to dopamine

Answer

Levodopa crosses the blood-brain barrier (unlike dopamine) and is decarboxylated to dopamine by DOPA decarboxylase in the CNS.

Question 5

A nurse administers flumazenil to reverse benzodiazepine sedation. What critical risk must be monitored for?

Accepted Answer

Resedation as flumazenil wears off before the benzodiazepine

Answer

Flumazenil has a shorter half-life (~1 hour) than most benzodiazepines, so resedation can occur when flumazenil is metabolized.

Pharmacology Practice Test