CADC Pharmacology of Substance Abuse 3 — Questions and Answers
Question 1: A client abruptly stops daily benzodiazepine use after 18 months. Which withdrawal symptom would be most medically concerning?
- Insomnia and anxiety
- Tonic-clonic seizures (Correct answer)
- Nausea and vomiting
- Intense drug craving
Correct answer: Tonic-clonic seizures
Abrupt benzodiazepine withdrawal can produce life-threatening tonic-clonic seizures due to GABA-A receptor down-regulation and glutamate rebound.
Question 2: Cocaine's primary mechanism of action in producing euphoria involves:
- Direct stimulation of dopamine receptors
- Blocking the reuptake of dopamine, serotonin, and norepinephrine (Correct answer)
- Releasing stored norepinephrine from nerve terminals
- Inhibiting monoamine oxidase (MAO)
Correct answer: Blocking the reuptake of dopamine, serotonin, and norepinephrine
Cocaine blocks monoamine transporter proteins (DAT, SERT, NET), preventing reuptake and causing accumulation of dopamine, serotonin, and norepinephrine in the synapse.
Question 3: Which pharmacokinetic factor most determines how long a benzodiazepine's effects last in the body?
- Protein binding percentage
- Half-life and presence of active metabolites (Correct answer)
- Bioavailability after oral administration
- Volume of distribution
Correct answer: Half-life and presence of active metabolites
The half-life determines how quickly a drug is eliminated, and long-acting benzodiazepines like diazepam produce active metabolites that extend their clinical duration.
Question 4: Methamphetamine differs from cocaine primarily because methamphetamine:
- Has a shorter duration of action than cocaine
- Actively causes release of dopamine in addition to blocking reuptake (Correct answer)
- Does not affect the norepinephrine system
- Cannot be smoked or injected
Correct answer: Actively causes release of dopamine in addition to blocking reuptake
Methamphetamine enters neurons and reverses the dopamine transporter, causing active dopamine release into the synapse in addition to blocking reuptake — making it more potent than cocaine.
Question 5: Which opioid medication used in MAT has a 'ceiling effect' on respiratory depression, making it safer in overdose compared to methadone?
- Morphine
- Buprenorphine (Correct answer)
- Hydromorphone
- Oxycodone
Correct answer: Buprenorphine
Buprenorphine is a partial mu-opioid agonist with a ceiling effect on respiratory depression, significantly reducing overdose risk compared to full agonists like methadone.
Question 6: The 'first-pass effect' is clinically significant in substance abuse pharmacology because it:
- Increases bioavailability of all orally administered drugs
- Reduces the amount of drug reaching systemic circulation after oral ingestion (Correct answer)
- Only applies to drugs administered intravenously
- Occurs primarily in the kidneys
Correct answer: Reduces the amount of drug reaching systemic circulation after oral ingestion
The first-pass effect describes hepatic metabolism of orally ingested drugs before they reach systemic circulation, which is why some drugs are less effective orally and why intravenous use bypasses it.
Question 7: Disulfiram (Antabuse) treats alcohol use disorder by:
- Reducing alcohol cravings through opioid receptor blockade
- Blocking aldehyde dehydrogenase, causing acetaldehyde accumulation (Correct answer)
- Competitively antagonizing alcohol at GABA receptors
- Enhancing serotonin signaling to reduce impulsivity
Correct answer: Blocking aldehyde dehydrogenase, causing acetaldehyde accumulation
Disulfiram inhibits aldehyde dehydrogenase, causing toxic acetaldehyde to accumulate when alcohol is consumed, producing a highly aversive reaction (flushing, nausea, palpitations).
CADC Pharmacology of Substance Abuse 3
A client abruptly stops daily benzodiazepine use after 18 months.
Which withdrawal symptom would be most medically concerning?