EXAM 4 UPDATED EXAM REVIEW 2026
QUESTIONS AND CORRECT SOLUTIONS
GRADED A+
⩥ What is the first step in acute overdose of acetaminophen? Answer:
Metabolism by conjugation becomes saturated, and excess APAP is
oxidatively metabolized by the CYP enzymes (CYP2E1, 1A2, 2A6, and
3A4) to the hepatotoxic reactive metabolite N-acetyl-p -
benzoquinoneimine (NAPQI).
⩥ Glutathione's role in acetaminophen biotransformation Answer:
Conjugates the hepatotoxic reactive metabolite N-acetyl-p -
benzoquinoneimine (NAPQI), which can then be renally excreted
⩥ Lack of glutathione or excessive NAPQI production can lead to
_______ . Answer: NAPQI binding to the cysteinyl sulfhydryl groups of
hepatocellular proteins, forming NAPQI-protein adducts. This causes an
ensuing cascade of oxidative damage and mitochondrial dysfunction.
The subsequent inflammatory response propagates hepatocellular injury
and death.
⩥ True or false: the ingested amount of APAP at which toxicity may
occur may be less in the setting of chronic ethanol use, malnutrition,
fasting, or viral illness. Answer: true
, ⩥ True or false: co-ingestions of substances or medications known to
induce the activity of the APAP-metabolizing cytochrome P (CYP)
oxidative enzymes also increase the risk of hepatotoxicity Answer: true
⩥ What is the antidote for acetaminophen poisoning? Answer: NAC, a
precursor of glutathione that increases the concentration of glutathione
available for the conjugation of NAPQI. Also enhances sulfate
conjugation of unmetabolized APAP, is an anti-inflammatory and
antioxidant, has positive inotropic effects, and increases local nitric
oxide concentrations for better blood flow.
⩥ A drug is ________ . Answer: an agent that affects biological
processes and is given to prevent or treat diease; most are weak acids or
bases
⩥ Pharmacokinetics Answer: The quantitative study of drug absorption,
distribution, metabolism, and excretion (ADME), and their mathematical
relationship; what the body does to the drug once its administered
⩥ The absorption of a drug is based on its ______ . Answer: solubility
(lipid or water soluble)
⩥ A protonated acid is _____ . Answer: non-ionized and lipid soluble