CASAC Pharmacology and Medication-Assisted Treatment 5 — Questions and Answers
Question 1: A client taking disulfiram (Antabuse) for alcohol use disorder consumes a mouthwash containing ethanol. What reaction is most likely to occur?
- No reaction because the ethanol dose is too small
- A disulfiram-ethanol reaction due to acetaldehyde accumulation (Correct answer)
- Mild sedation from combined CNS depressant effects
- Increased alcohol craving due to sensory priming
Correct answer: A disulfiram-ethanol reaction due to acetaldehyde accumulation
Even small amounts of ethanol, including in mouthwash, can trigger a disulfiram-ethanol reaction characterized by flushing, tachycardia, nausea, and vomiting due to acetaldehyde buildup.
Question 2: Which of the following best describes the pharmacological mechanism of naltrexone in treating alcohol use disorder?
- It blocks alcohol metabolism causing aversion to drinking
- It antagonizes opioid receptors, reducing the rewarding effects of alcohol (Correct answer)
- It enhances GABA activity to reduce alcohol withdrawal symptoms
- It increases dopamine release to substitute for alcohol's reward
Correct answer: It antagonizes opioid receptors, reducing the rewarding effects of alcohol
Naltrexone blocks mu-opioid receptors, dampening the endorphin-mediated euphoric reward from alcohol and reducing the reinforcing 'high' that drives continued drinking.
Question 3: A client with opioid use disorder is interested in extended-release injectable naltrexone (Vivitrol). Which condition must be met before the first injection?
- Client must complete a 30-day inpatient detox program
- Client must be opioid-free for 7–10 days to avoid precipitated withdrawal (Correct answer)
- Client must pass a urine drug screen negative for all substances including cannabis
- Client must first fail a trial of buprenorphine therapy
Correct answer: Client must be opioid-free for 7–10 days to avoid precipitated withdrawal
Extended-release naltrexone must not be initiated until the client is opioid-free for at least 7–10 days; administration to an opioid-dependent person causes severe precipitated withdrawal.
Question 4: Varenicline (Chantix) assists smoking cessation by acting as a partial agonist at which receptor?
- Cannabinoid CB1 receptors
- Alpha-4 beta-2 nicotinic acetylcholine receptors (Correct answer)
- Mu opioid receptors
- Dopamine D2 receptors
Correct answer: Alpha-4 beta-2 nicotinic acetylcholine receptors
Varenicline partially activates alpha-4 beta-2 nicotinic acetylcholine receptors, reducing cravings while blocking nicotine from producing its full rewarding effect.
Question 5: A pregnant client with opioid use disorder is being evaluated for MAT. According to clinical guidelines, which approach is recommended over medically supervised withdrawal during pregnancy?
- Rapid opioid detox under general anesthesia
- Maintenance therapy with methadone or buprenorphine (Correct answer)
- Clonidine-only protocol to minimize fetal exposure
- Gradual taper with oral morphine over 90 days
Correct answer: Maintenance therapy with methadone or buprenorphine
SAMHSA and ACOG guidelines recommend methadone or buprenorphine maintenance during pregnancy because withdrawal significantly increases risk of fetal distress, preterm labor, and miscarriage.
Question 6: Which side effect is most associated with buprenorphine therapy that clients should be counseled about before starting treatment?
- Severe hypertension and tachycardia
- Constipation, headache, and insomnia (Correct answer)
- Irreversible liver damage within the first month
- Rapid weight gain and metabolic syndrome
Correct answer: Constipation, headache, and insomnia
Common side effects of buprenorphine include constipation (opioid receptor-mediated), headache, and insomnia, which clients should be prepared to manage.
Question 7: A counselor learns that a client stable on methadone maintenance for two years wants to discontinue MAT. What is the evidence-based counseling response?
- Support immediate discontinuation as the client has achieved stability
- Advise a very gradual taper and discuss the significantly increased overdose risk after stopping (Correct answer)
- Recommend switching to buprenorphine first, then discontinuing within 30 days
- Inform the client that discontinuation is not permitted within the first five years
Correct answer: Advise a very gradual taper and discuss the significantly increased overdose risk after stopping
Evidence shows relapse and overdose mortality increase substantially after MAT discontinuation; counselors should support a very gradual taper and ensure the client understands the risks.
CASAC Pharmacology and Medication-Assisted Treatment 5
A client taking disulfiram (Antabuse) for alcohol use disorder consumes a mouthwash containing ethanol.
What reaction is most likely to occur?