CADC Pharmacology of Substance Abuse 2 — Questions and Answers
Question 1: Which neurotransmitter system is primarily responsible for the reinforcing effects of most addictive substances?
- Serotonin
- Dopamine (Correct answer)
- GABA
- Acetylcholine
Correct answer: Dopamine
Dopamine release in the nucleus accumbens (the brain's reward center) is the primary mechanism behind the reinforcing properties of addictive drugs.
Question 2: A client reports using heroin daily for two years. Which opioid receptor type is most responsible for heroin's analgesic and euphoric effects?
- Kappa (κ)
- Delta (δ)
- Mu (μ) (Correct answer)
- Sigma (σ)
Correct answer: Mu (μ)
Mu (μ) opioid receptors mediate the primary analgesic, euphoric, and respiratory-depressant effects of heroin and other opioids.
Question 3: Naloxone reverses opioid overdose by acting as a:
- Partial agonist at mu receptors
- Full agonist at kappa receptors
- Competitive antagonist at opioid receptors (Correct answer)
- Reuptake inhibitor of dopamine
Correct answer: Competitive antagonist at opioid receptors
Naloxone is a competitive opioid receptor antagonist that rapidly displaces opioids from their receptors, reversing respiratory depression.
Question 4: Which statement best describes cross-tolerance in substance abuse pharmacology?
- Tolerance to one drug causing increased sensitivity to unrelated drugs
- Tolerance developed to one drug that reduces the effect of a pharmacologically similar drug (Correct answer)
- Two drugs producing opposite effects when combined
- A drug losing effectiveness due to metabolic changes only
Correct answer: Tolerance developed to one drug that reduces the effect of a pharmacologically similar drug
Cross-tolerance occurs when tolerance to one drug confers tolerance to another drug in the same pharmacological class, such as tolerance to alcohol reducing the effects of benzodiazepines.
Question 5: The phenomenon where a drug produces progressively stronger effects with repeated administration at the same dose is called:
- Tolerance
- Sensitization (reverse tolerance) (Correct answer)
- Tachyphylaxis
- Pharmacodynamic tolerance
Correct answer: Sensitization (reverse tolerance)
Sensitization (or reverse tolerance) describes increasing drug effects with repeated use, commonly seen with stimulants like cocaine causing escalating psychosis.
Question 6: Which route of drug administration produces the fastest onset of action and highest peak blood concentration?
- Oral ingestion
- Intranasal (snorting)
- Intravenous injection (Correct answer)
- Transdermal patch
Correct answer: Intravenous injection
Intravenous injection delivers the drug directly into the bloodstream, bypassing all absorption barriers and producing near-immediate peak levels.
Question 7: Alcohol primarily exerts its CNS depressant effects by:
- Blocking dopamine reuptake transporters
- Enhancing GABA-A receptor activity and inhibiting NMDA glutamate receptors (Correct answer)
- Stimulating serotonin 5-HT3 receptors exclusively
- Activating mu opioid receptors
Correct answer: Enhancing GABA-A receptor activity and inhibiting NMDA glutamate receptors
Alcohol enhances inhibitory GABA-A signaling and suppresses excitatory NMDA glutamate receptors, producing its sedating and disinhibiting effects.
CADC Pharmacology of Substance Abuse 2
Which neurotransmitter system is primarily responsible for the reinforcing effects of most addictive substances?