CAADE Pharmacology of Substances 5 — Questions and Answers
Question 1: Which drug is most associated with the pharmacological phenomenon of 'kindling' during repeated withdrawal episodes?
- Cannabis
- Cocaine
- Alcohol (Correct answer)
- Heroin
Correct answer: Alcohol
Kindling refers to the progressive worsening of alcohol withdrawal symptoms with each successive episode, increasing seizure risk with repeated detoxifications.
Question 2: What distinguishes pharmacodynamic tolerance from pharmacokinetic tolerance?
- Pharmacodynamic tolerance involves faster drug metabolism; pharmacokinetic involves receptor changes
- Pharmacodynamic tolerance involves receptor downregulation or desensitization; pharmacokinetic involves faster drug metabolism (Correct answer)
- They are the same process described differently
- Pharmacokinetic tolerance only occurs with opioids
Correct answer: Pharmacodynamic tolerance involves receptor downregulation or desensitization; pharmacokinetic involves faster drug metabolism
Pharmacodynamic tolerance results from receptor-level adaptations (downregulation/desensitization), while pharmacokinetic tolerance results from increased metabolic enzyme activity breaking down the drug faster.
Question 3: Which of the following best describes the 'reward pathway' central to addiction?
- The hypothalamic-pituitary-adrenal axis regulating stress hormones
- The mesolimbic dopamine pathway from the ventral tegmental area to the nucleus accumbens (Correct answer)
- The prefrontal cortex to amygdala serotonin pathway
- The nigrostriatal dopamine pathway controlling movement
Correct answer: The mesolimbic dopamine pathway from the ventral tegmental area to the nucleus accumbens
The mesolimbic pathway, projecting from the VTA to the nucleus accumbens, mediates reward, motivation, and is the central circuit hijacked by addictive substances.
Question 4: A client prescribed disulfiram (Antabuse) drinks alcohol. What pharmacological reaction occurs?
- Enhanced alcohol metabolism producing rapid intoxication
- Acetaldehyde accumulation causing flushing, nausea, and cardiovascular distress (Correct answer)
- Opioid receptor activation producing sedation
- Serotonin syndrome with hyperthermia
Correct answer: Acetaldehyde accumulation causing flushing, nausea, and cardiovascular distress
Disulfiram inhibits aldehyde dehydrogenase, causing toxic acetaldehyde to accumulate when alcohol is consumed, producing an aversive flushing and nausea reaction.
Question 5: Which statement about LSD's pharmacological mechanism is correct?
- LSD primarily blocks dopamine D2 receptors
- LSD is a partial agonist at serotonin 5-HT2A receptors, producing hallucinations (Correct answer)
- LSD works by releasing large amounts of acetylcholine
- LSD acts as an NMDA receptor antagonist like PCP
Correct answer: LSD is a partial agonist at serotonin 5-HT2A receptors, producing hallucinations
LSD's hallucinogenic effects are primarily mediated through partial agonism at serotonin 5-HT2A receptors in the cortex.
Question 6: Methadone's effectiveness in opioid use disorder treatment is largely due to which pharmacological property?
- Its short half-life requiring frequent dosing keeps patients engaged in treatment
- Its long half-life (24-36 hours) prevents withdrawal and reduces cravings with once-daily dosing (Correct answer)
- It completely blocks all opioid receptors, preventing any opioid effect
- It converts to heroin in the body, providing a safer substitute
Correct answer: Its long half-life (24-36 hours) prevents withdrawal and reduces cravings with once-daily dosing
Methadone's long half-life of 24-36 hours allows once-daily dosing to prevent withdrawal symptoms and cravings while stabilizing opioid-dependent patients.
Question 7: Which term describes the phenomenon where repeated exposure to a drug results in an enhanced response rather than tolerance?
- Reverse tolerance (sensitization) (Correct answer)
- Cross-tolerance
- Tachyphylaxis
- Pharmacodynamic tolerance
Correct answer: Reverse tolerance (sensitization)
Reverse tolerance, or sensitization, occurs when repeated drug exposure increases the behavioral or psychological response, commonly seen with stimulants like cocaine.
CAADE Pharmacology of Substances 5
Which drug is most associated with the pharmacological phenomenon of 'kindling' during repeated withdrawal episodes?