CARN Pharmacology & Substance Use Disorders 4 — Questions and Answers
Question 1: A patient using methamphetamine presents with severe hyperthermia and agitation. In addition to cooling measures, which medication class is most appropriate for immediate management?
- Opioid analgesics
- Benzodiazepines (Correct answer)
- Antipsychotics alone
- Beta-blockers
Correct answer: Benzodiazepines
Benzodiazepines are first-line for methamphetamine-induced agitation and hyperthermia because they reduce CNS excitation without the risks associated with antipsychotics in stimulant toxicity.
Question 2: Which of the following best describes the pharmacokinetic advantage of the buprenorphine transdermal patch compared to sublingual formulations?
- Higher bioavailability and faster onset of action
- Avoidance of first-pass metabolism and steady plasma levels (Correct answer)
- Greater ceiling effect on analgesia
- Elimination via renal excretion only
Correct answer: Avoidance of first-pass metabolism and steady plasma levels
Transdermal buprenorphine bypasses first-pass hepatic metabolism and provides consistent plasma concentrations over days, improving adherence and reducing peak-trough fluctuations.
Question 3: A nurse notes that a patient's urine drug screen is positive for fentanyl but the patient denies using fentanyl and only admits to heroin use. The most appropriate interpretation is:
- The patient is lying about fentanyl use and should be confronted
- Illicitly obtained heroin is often adulterated with fentanyl, so the result is consistent with the patient's report (Correct answer)
- The urine screen cross-reacted with heroin metabolites
- Fentanyl from a pain patch was misused
Correct answer: Illicitly obtained heroin is often adulterated with fentanyl, so the result is consistent with the patient's report
Illicit drug supplies, including heroin, are frequently contaminated with fentanyl; a fentanyl-positive screen in a self-reported heroin user is commonly explained by adulteration.
Question 4: The CARN nurse is reviewing medications for a patient with co-occurring opioid use disorder and major depressive disorder on buprenorphine. Which antidepressant combination requires the most caution due to CYP3A4 interactions?
- Sertraline
- Mirtazapine
- Fluoxetine and fluvoxamine (Correct answer)
- Bupropion
Correct answer: Fluoxetine and fluvoxamine
Fluoxetine and fluvoxamine significantly inhibit CYP3A4 and CYP2D6, potentially increasing buprenorphine plasma levels and requiring dose monitoring.
Question 5: Neonatal opioid withdrawal syndrome (NOWS) is most reliably assessed using which tool?
- CIWA-Ar scale
- Finnegan Neonatal Abstinence Scoring Tool (Correct answer)
- AUDIT-C questionnaire
- DAST-10 scale
Correct answer: Finnegan Neonatal Abstinence Scoring Tool
The Finnegan Neonatal Abstinence Scoring Tool is the standard validated instrument for assessing severity of NOWS and guiding pharmacological treatment decisions.
Question 6: A patient prescribed naltrexone for alcohol use disorder reports daily opioid pain medication use. The nurse's priority action is to:
- Administer the naltrexone as prescribed since alcohol is the primary concern
- Consult the prescriber before administering because naltrexone will precipitate opioid withdrawal (Correct answer)
- Switch the patient to methadone maintenance
- Hold all medications until withdrawal resolves
Correct answer: Consult the prescriber before administering because naltrexone will precipitate opioid withdrawal
Naltrexone will precipitate acute opioid withdrawal in a physically dependent patient, so the prescriber must be alerted before administration.
Question 7: Which pharmacological property of methadone makes it particularly effective for patients who experience opioid-induced hyperalgesia?
- Strong GABA-B receptor agonism
- NMDA receptor antagonism in addition to mu-opioid agonism (Correct answer)
- Selective kappa-opioid antagonism
- High protein binding preventing CNS entry
Correct answer: NMDA receptor antagonism in addition to mu-opioid agonism
Methadone's NMDA receptor antagonism helps counter opioid-induced hyperalgesia, a condition where opioid use paradoxically increases pain sensitivity.
CARN Pharmacology & Substance Use Disorders 4
A patient using methamphetamine presents with severe hyperthermia and agitation.
In addition to cooling measures, which medication class is most appropriate for immediate management?