Mechanism of Action
Which receptor is primarily responsible for euphoria and physical dependence?
a. Mu
b. Kappa
c. Nicotinic
d. GABA
Rationale: A is correct because mu receptors are primary binding site which contribute to analgesia, respiratory depression, euphoria, sedation and physical dependence.
Why B, C, and D are incorrect: Kappa is involved but for other effects, nicotinic is for autonomic drugs, and GABA is for benzos.
A patient beginning long-term morphine therapy should routinely receive which bowel regimen?
a. Stool softener only
b. Bulk-forming laxative only
c. No bowel regimen is needed as long as they increase fluids
d. Stimulant laxative plus stool softener
Rationale: D is the correct answer because opioids decrease GI motility and commonly cause constipation. A stimulant laxative promotes peristalsis, while a stool softener helps soften the stool and make it easier to pass. A bowel regimen should be started prophylactically when beginning long-term opioid therapy rather than waiting for constipation to occur.
Why A, B, and C are incorrect: A stool softener alone does not stimulate bowel motility and is generally not enough to prevent opioid-induced constipation. Bulk-forming laxatives can increase stool bulk without improving the opioid-related decrease in GI motility and may worsen constipation. Increasing fluids is helpful but is not enough by itself to prevent opioid-induced constipation.
Which patient should not receive meperidine?
a. A patient with a history of biliary tract surgery
b. A patient with renal failure
c. A patient with postoperative pain
d. A patient with chronic osteoarthritis
Rationale: B is the correct answer because when the drug breaks down, it turns into normeperidine. Normeperidine is toxic and can accumulate in patients with impaired renal function.
Why A, C, and D are incorrect: Morphine is contraindicated after biliary tract surgery, no contraindication in postoperative pain, meperidine is not recommended for chronic pain but is not as dangerous as meperidine is to renal failure.
NCLEX: A patient improves after naloxone for opioid-induced respiratory depression 30 minutes ago. Why should the nurse continue to monitor up to 2-24 hours?
a. Respiratory depression may recur because naloxone has a shorter duration than many opioids
b. Discontinue all monitoring since the naloxone reversed the toxicity
c. Naloxone permanently blocks opioid receptors
d. Naloxone causes delayed respiratory depression
Rationale: A is the correct answer because naloxone has a duration of action of 60-90 minutes and opioids have a longer half-life. Respiratory depression can reoccur, so it is important to monitor for at least 2 hours up to 24 hours and repeat only if respiratory depression recurs.
Why B, C, and D are incorrect: Opioids have a longer half-life than naloxone and giving more than needed can cause tachycardia, tachypnea and abstinence syndrome.
Which route should be questioned if ordered by the provider for naloxone?
a. Oral
b. Intravenous
c. Intramuscular
d. Subcutaneous
Rationale: A is the correct answer because naloxone will undergo first-pass inactivation which means if administered orally it will have very little therapeutic effect.
Why B, C, and D are incorrect: IV, IM, and SUBQ have a higher therapeutic effect than orally and are all acceptable routes.
How do opioid antagonist such as naloxone work at receptor level?
a. Stimulate mu receptors more strongly than opioids
b. They increase release of endogenous endorphins
c. They permanently destroy opioid receptors
d. Compete for and displace opioid agonists from receptor binding sites
Rationale: D is the correct answer because naloxone is an opioid antagonist which displaces agonist from binding site.
Why A, B, and C are incorrect: Does not stimulate mu receptors at all, does not affect endorphins, and receptor binding is temporary and reversible.
Which medication belongs to the agonist-antagonist opioid class
a. Morphine
b. Naloxone
c. Butorphanol
d. Methadone
Rationale: C is the correct answer
Why A, B, and D are incorrect: Morphine and methadone are an opioid agonists and naloxone is an opioid antagonist.
Which of the following medication classes cause additive CNS/respiratory depression when combined with opioids?
a. Antibiotics and alcohol
b. Glucocorticoids
c. Benzodiazepines, alcohol, and barbiturates
d. Loop diuretics
Rationale: C is the correct answer because these can have additive depressant effects when combined with opioids.
Why A, B and D are incorrect: These drugs do not have significant CNS depression when combined with opioids.
NCLEX: A nurse is developing a plan of care a patient beginning long-term opioid therapy for cancer pain. Which prophylactic bowel regimen should the nurse anticipate?
a. Bulk-forming laxative only
b. Antidiarrheal agent as needed
c. Stimulant laxative with or without stool softener
d. No bowel regimen unless constipation occurs
Rationale: C is the correct answer because one of the big side effects is opioid-induced constipation. In addition to recommending laxatives with or without stool softener, it is important to teach to increase fluids as well.
Why is A, B, and D incorrect: Bulk-forming is contraindicated because it can create a larger stool that is harder to move, opioids do cause constipation so it wouldn’t help, and no bowel regimen was an outdated approach no longer encouraged.
A neonatal nurse is caring for a premature infant experiencing pain. Which of the following opioid analgesics would the nurse identify as contraindicated for this patient?
a. Fentanyl
b. Morphine
c. Methadone
d. Ibuprofen
Rationale: B is the correct answer because morphine is contraindicated in premature newborns since it can cause respiratory depression.
Why A, C, and D are incorrect: Fentanyl has a shorter half-life and is more predictable, methadone is used for opioid withdrawal in neonates, and ibuprofen has risks in premature newborns but is not an opioid analgesic.
Why does butorphanol have a lower abuse potential and less respiratory depression than morphine?
a. It has no receptor activity at all
b. It acts as an antagonist at mu receptors while acting as an agonist at kappa receptors
c. It acts as an agonist at both mu and kappa receptors, like morphine
d. It blocks all opioid receptors completely
Rationale: B is correct because it is an agonist-antagonist which means it blocks mu receptor activity and continues to activate kappa receptors for analgesia.
Why A, C, and D are incorrect: It does have receptor activity but does not act as an agonist on the receptors or block both receptors.
NCLEX: A nurse is caring for a patient in renal failure who requires opioid analgesia. Which opioid should the nurse question if prescribed?
a. Morphine
b. Hydromorphone
c. Meperidine
d. Fentanyl
Rationale: C is the correct answer because meperidine is contraindicated in patients with renal failure. The drug is metabolized to normeperidine which is toxic and can accumulate in a kidney that is unable to filter it out.
Why A, B, and D are incorrect: Morphine may need caution but does not cause same issue as meperidine, hydromorphone may need caution when using but generally safe, and fentanyl is preferred with renal failure because it isn’t cleared renally.
NCLEX: A nurse enters the room and finds a patient receiving IV morphine difficult to arouse. Assessment reveals: RR 8/min, pinpoint pupils, and unresponsive to verbal stimuli. What is the priority nursing action?
a. Administer the next opioid dose
b. Hold the opioid, administer naloxone, and notify the provider
c. Encourage deep breathing
d. Hold dose and reassess in 30 minutes
Rationale: B is the correct answer because coma, pinpoint pupils, and RR>12/min may indicate that the patient is experiencing opioid toxicity triad. When this happens, dose must be help, naloxone must be administered and provider must be notified.
Why A, C, and D are incorrect: Administering next dose and/or not administering naloxone could be fatal based on the symptoms.
NCLEX: A nurse is administering IV fentanyl to a postoperative client. What is the right technique?
a. Give as a rapid IV bolus over 30 seconds
b. Double check and administer slowly over 5 minutes using yesterday’s respiratory rate
c. Double check and push medication slowly over 5 minutes after verifying respirations and having naloxone available
d. A fentanyl patch works immediately
Rationale: C is the correct answer because giving the opioid over 5 minutes and having naloxone readily available allows for prepares for prompt treatment if the patient experiences respiratory depression.
Why A, B and D are incorrect: Giving medication fast can dangerously decrease BP and RR, double-checking dose is best practice, fentanyl patch takes 24 hours to reach therapeutic effect.
Which drug combination is contraindicated due to risk of hyperpyrexic coma?
a. Morphine + acetaminophen
b. Fentanyl + antihypertensives
c. Butorphanol + antiemetics
d. Meperidine + MAOIs
Rationale: D is the correct answer because meperidine + MAOIs can cause hyperpyrexic coma, delirium, seizures, and respiratory depression.
Why A, B, and C are incorrect: Opioid agonists with acetaminophen - generally safe together, opioid agonist-antagonists with hypertensives – can cause hypotension but not cause hyperpyrexic coma, and opioid agonist with antiemetics – can increase sedation but not hyperpyrexic coma.
NCLEX: A nurse providing teaching to a patient about morphine’s mechanism of action. Which statement is accurate regarding kappa receptors?
a. It is the primary receptor responsible for euphoria and dependence
b. It has no clinical effect in humans
c. It contributes to analgesia, sedation, and decreased GI motility
d. It causes increased bowel motility and diarrhea
Rationale: C is correct because kappa receptor activation produces analgesia, sedation, and decreased GI motility (constipation).
Why A, B, and D are incorrect: Mu receptor is primarily responsible for euphoria, dependence, and respiratory depression. Kappa does have an effect in humans. Increased bowel motility and diarrhea are the opposite of kappa’s MOA.
NCLEX: A client with end-stage cancer receiving morphine (long-term) has severe constipation that is unrelieved by a stimulant laxative and stool softner. Which medication should the nurse expect the provider to prescribe?
a. Methylnaltrexone
b. Naloxone
c. Loperamide
d. Additional morphine
Rationale: A is the correct answer because methylnaltrexone is an opioid antagonist which is preferred with opioid-induced constipation and is peripherally acting.
Why B, C, and D are incorrect: Naloxone is used for overdose reversal (centrally acting), loperamide is an opioid agonist which can cause more constipation, and additional morphine would also cause more constipation.
NCLEX: A client who is physically dependent on morphine is prescribed butorphanol for additional pain control. Which finding should the nurse recognize as a priority concern?
a. Mild sedation
b. Slight decrease in blood pressure
c. Improved analgesia
d. Onset of abstinence syndrome
Rationale: D is the correct answer because agonist-antagonists can precipitate abstinence syndrome. Never combine an agonist-antagonist with a pure agonist because it can precipitate withdrawal
Why A, B and C are incorrect: These are all common side effects to be expected with agonist-antagonists.
A nurse is caring for 3 patients receiving opioid therapy for different conditions. Which nursing action is incorrect?
a. For a patient at risk for orthostatic hypotension, instruct patient to rise slowly and sit on edge of bed before standing up
b. For patient receiving codeine for cough suppression, monitor lung sounds and hydration status
c. For a patient at risk for urinary retention, palpate the bladder and monitor intake/output every 24 hours
Rationale: C is the correct answer because with patients who are at risk for urinary retention, it is important to palpate the bladder and monitor the I&O’s but should be done every 4-6 hours because the urge to void is reduced even when the bladder is full.
Why A and B are incorrect: Patients at risk for orthostatic hypotension should be instructed to change positions slowly because of dizziness. Codeine requires respiratory monitoring because it has antitussive use because it decreases the activity of the brain that triggers a cough reflex.
A nurse is reviewing the medication list of a patient who is starting long-term opioid therapy. The patient’s current medication includes amitriptyline (tricyclic antidepressant) and lisinopril (an antihypertensive). What are the potential interactions should the nurse monitor for? Select all that apply.
a. Increased risk of constipation and urinary retention
b. Increased risk of hypotension
c. Increased risk of hyperglycemia
d. Increased risk of respiratory depression
Rationale: A and B are correct because both have drug interactions with opioid agonists. TCAs (as well as anticholinergics): additive anticholinergic effects meaning can’t see, can’t pee, can’t shpoop which is why A is correct. Antihypertensives: additive hypotensive effects which is why B is correct.
Why C and D are incorrect: Hyperglycemia is not an effect from these drugs combines with opioids and respiratory depression is from CNS depressant interactions.