CAADE Pharmacology of Substances 3 — Questions and Answers
Question 1: Which route of administration produces the fastest onset of drug effects?
- Oral ingestion
- Intramuscular injection
- Intravenous injection (Correct answer)
- Transdermal patch
Correct answer: Intravenous injection
Intravenous injection delivers the drug directly into the bloodstream, bypassing absorption barriers and producing onset within seconds.
Question 2: PCP (phencyclidine) produces its dissociative effects primarily through which mechanism?
- Agonism at serotonin 5-HT2A receptors
- Antagonism at NMDA glutamate receptors (Correct answer)
- Agonism at mu-opioid receptors
- Reuptake inhibition of dopamine and serotonin
Correct answer: Antagonism at NMDA glutamate receptors
PCP acts as an NMDA receptor antagonist, blocking glutamate activity and causing dissociation, hallucinations, and anesthesia.
Question 3: What is the mechanism by which naloxone reverses opioid overdose?
- It stimulates respiratory drive by activating serotonin receptors
- It competitively displaces opioids from mu-opioid receptors as an antagonist (Correct answer)
- It accelerates opioid metabolism in the liver
- It increases dopamine release to counteract CNS depression
Correct answer: It competitively displaces opioids from mu-opioid receptors as an antagonist
Naloxone is a competitive mu-opioid receptor antagonist that displaces opioids from receptors, rapidly reversing respiratory depression and sedation.
Question 4: Which of the following best describes a 'set and setting' influence on drug effects?
- The pharmacokinetics of the drug in the body
- The user's mindset and physical environment, which shape subjective drug experience (Correct answer)
- The specific dosage and purity of the substance
- The method by which the drug is metabolized
Correct answer: The user's mindset and physical environment, which shape subjective drug experience
Set and setting, coined by Timothy Leary, refers to the user's mental state (set) and physical/social environment (setting) as key factors shaping drug experience.
Question 5: Chronic heavy alcohol use leads to nutritional deficiency of thiamine (B1), which can cause which neurological condition?
- Korsakoff's syndrome and Wernicke's encephalopathy (Correct answer)
- Tardive dyskinesia
- Parkinson's disease
- Multiple sclerosis
Correct answer: Korsakoff's syndrome and Wernicke's encephalopathy
Thiamine deficiency from chronic alcohol use causes Wernicke's encephalopathy (acute) and Korsakoff's syndrome (chronic amnestic disorder).
Question 6: Which class of drugs acts by inhibiting the reuptake of monoamine neurotransmitters (dopamine, norepinephrine, serotonin) and includes cocaine?
- Depressants
- Hallucinogens
- Stimulants (Correct answer)
- Dissociatives
Correct answer: Stimulants
Stimulants like cocaine block monoamine transporters, increasing synaptic concentrations of dopamine, norepinephrine, and serotonin.
Question 7: What is cross-tolerance, and which pair of substances best illustrates it?
- Increased sensitivity due to prior exposure; illustrated by alcohol and caffeine
- Reduced effect of one drug due to tolerance developed to a pharmacologically similar drug; illustrated by alcohol and benzodiazepines (Correct answer)
- Enhanced effects when two drugs are combined; illustrated by heroin and cocaine
- Withdrawal from one drug triggered by another; illustrated by opioids and stimulants
Correct answer: Reduced effect of one drug due to tolerance developed to a pharmacologically similar drug; illustrated by alcohol and benzodiazepines
Cross-tolerance occurs when tolerance to one substance reduces the effects of a pharmacologically related substance, as seen with alcohol and benzodiazepines (both GABA enhancers).
CAADE Pharmacology of Substances 3
Which route of administration produces the fastest onset of drug effects?