CARN Pharmacology in Addictions Nursing 3 — Questions and Answers
Question 1: A patient receiving extended-release naltrexone (Vivitrol) injection reports that heroin had no effect when used. This best demonstrates which pharmacological property?
- Competitive inhibition reversible by high-dose opioids
- Irreversible enzyme inhibition
- Sustained opioid receptor blockade preventing euphoria (Correct answer)
- Negative reinforcement through aversive effects
Correct answer: Sustained opioid receptor blockade preventing euphoria
Extended-release naltrexone provides continuous opioid receptor blockade for approximately 30 days, preventing opioids from producing euphoria.
Question 2: During alcohol withdrawal, lorazepam is often preferred over diazepam in patients with severe liver disease. Why?
- Lorazepam has a longer half-life requiring less frequent dosing
- Lorazepam undergoes direct glucuronidation and does not rely on oxidative hepatic metabolism (Correct answer)
- Lorazepam has a lower risk of respiratory depression
- Lorazepam has no active metabolites and requires cytochrome P450 enzymes
Correct answer: Lorazepam undergoes direct glucuronidation and does not rely on oxidative hepatic metabolism
Lorazepam is metabolized via direct glucuronidation, bypassing CYP450 enzymes compromised in liver disease, preventing toxic accumulation.
Question 3: Which opioid withdrawal medication works by stimulating alpha-2 adrenergic receptors to reduce autonomic symptoms like diaphoresis and tachycardia?
- Methadone
- Buprenorphine
- Clonidine (Correct answer)
- Naloxone
Correct answer: Clonidine
Clonidine is an alpha-2 agonist that reduces noradrenergic hyperactivity in the locus coeruleus, relieving autonomic opioid withdrawal symptoms.
Question 4: A patient on buprenorphine/naloxone (Suboxone) attempts to inject the crushed film. What is the expected outcome?
- Intensified opioid effect due to intravenous buprenorphine
- Precipitated withdrawal from naloxone's systemic effects when injected (Correct answer)
- No effect because buprenorphine is insoluble
- Severe hepatotoxicity from naloxone injection
Correct answer: Precipitated withdrawal from naloxone's systemic effects when injected
When injected, naloxone achieves systemic bioavailability and antagonizes opioid receptors, precipitating acute withdrawal — the intended abuse-deterrent mechanism.
Question 5: Which CARN-relevant pharmacological concept explains why tolerance develops more quickly to opioid euphoria than to opioid-induced constipation?
- Constipation receptors are in the periphery and less affected by CNS adaptation
- Different opioid receptor subtypes mediate each effect, with varying rates of desensitization
- Gastrointestinal receptors do not undergo downregulation as rapidly as CNS receptors (Correct answer)
- Constipation is mediated by kappa receptors, which are inherently more stable
Correct answer: Gastrointestinal receptors do not undergo downregulation as rapidly as CNS receptors
Enteric nervous system mu-opioid receptors downregulate slowly compared to CNS reward receptors, so constipation persists while euphoria diminishes with chronic use.
Question 6: A patient prescribed buprenorphine reports it is not controlling cravings adequately. The nurse should first assess:
- Whether the patient should switch to methadone immediately
- Sublingual absorption technique, dose timing, and concurrent substance use (Correct answer)
- Whether naltrexone should be added to the regimen
- The patient's motivation for recovery using the CAGE questionnaire
Correct answer: Sublingual absorption technique, dose timing, and concurrent substance use
Inadequate buprenorphine effect is often due to poor sublingual technique, incorrect timing, or concurrent opioid use rather than immediately requiring dose escalation or medication change.
Question 7: Which FDA-approved medication for opioid use disorder is available only through federally certified opioid treatment programs (OTPs) for daily observed dosing?
- Buprenorphine monoproduct (Subutex)
- Naltrexone (Vivitrol)
- Methadone liquid formulation for OUD (Correct answer)
- Buprenorphine/naloxone (Suboxone)
Correct answer: Methadone liquid formulation for OUD
Methadone for OUD treatment is restricted to federally certified OTPs where it is dispensed as a liquid for daily observed dosing due to its high overdose risk.
CARN Pharmacology in Addictions Nursing 3
A patient receiving extended-release naltrexone (Vivitrol) injection reports that heroin had no effect when used.
This best demonstrates which pharmacological property?