FPGEE Toxicology 4

Question 1

A patient presents with altered mental status, hyperthermia, diaphoresis, and hyperreflexia after starting linezolid while already on sertraline. What is the most likely diagnosis?

Accepted Answer

Serotonin syndrome

Answer

Linezolid is an MAO inhibitor; combined with an SSRI it causes excess serotonin activity resulting in serotonin syndrome characterized by hyperthermia, clonus, and agitation.

Question 2

The LD50 is a toxicological parameter that represents:

Accepted Answer

The lethal dose for 50% of a test animal population

Answer

LD50 (median lethal dose) is the dose of a substance required to kill 50% of the test population under specific experimental conditions, used to compare acute toxicity.

Question 3

Which of the following correctly describes zero-order (saturation) toxicokinetics?

Accepted Answer

A constant amount of drug is eliminated per unit time

Answer

Zero-order kinetics occur when elimination pathways are saturated; a fixed amount (not fraction) is eliminated per unit time, leading to disproportionate increases in drug levels with dose increases.

Question 4

A child ingests iron tablets. During the latent phase (6-24 hours post-ingestion), the patient appears to improve. What dangerous misconception can this create?

Accepted Answer

The false sense of recovery may delay needed treatment before systemic toxicity begins

Answer

The latent phase of iron poisoning creates a deceptive improvement after initial GI symptoms, but systemic toxicity, hepatic failure, and circulatory collapse may follow without treatment.

Question 5

Which of the following correctly pairs a toxin with its specific antidote?

Accepted Answer

Heparin — protamine sulfate

Answer

Protamine sulfate neutralizes heparin by forming an inactive complex; it is the specific antidote for heparin-induced anticoagulation.

FPGEE Exam Practice Test

FPGEE Exam Practice Test

FPGEE Toxicology 4