CFPN Toxicology and Pharmacology in Forensic Cases

Question 1

Which analytical method is considered the gold standard for confirming positive drug screening results in forensic toxicology?

Accepted Answer

Gas chromatography–mass spectrometry (GC-MS)

Answer

GC-MS provides definitive identification and quantification of substances, making it the confirmatory gold standard.

Question 2

A drug that has a half-life of 4 hours will be reduced to approximately what percentage of its original concentration after 12 hours?

Accepted Answer

12.5%

Answer

After three half-lives (4 × 3 = 12 hours), a drug is reduced to (0.5)³ = 12.5% of its original concentration.

Question 3

Which specimen provides the longest detection window for most drugs of abuse in forensic testing?

Accepted Answer

Hair

Answer

Hair retains drug metabolites for months, providing the longest detection window compared to other biological specimens.

Question 4

Benzodiazepines are typically detectable in urine for how long after therapeutic use?

Accepted Answer

3–7 days for short-acting; up to 6 weeks for long-acting

Answer

Detection windows vary significantly between short-acting and long-acting benzodiazepines based on their metabolites and half-lives.

Question 5

What is the primary metabolite of cocaine that is detected in forensic urine drug screens?

Accepted Answer

Benzoylecgonine

Answer

Benzoylecgonine is the major urinary metabolite of cocaine and the target analyte in standard immunoassay screens.

CFPN - Certified Forensic Pharmacy Nurse Practice Test