Morphine poisoning – symptoms and management is a vital topic for B. Pharm students, covering opioid pharmacology, overdose recognition, and emergency care. This introduction reviews the opioid toxidrome—respiratory depression, miosis, reduced consciousness, and hypoventilation—alongside mechanisms (mu receptor agonism), key investigations, and management principles including airway support, naloxone reversal, activated charcoal, and monitoring for recurrent toxicity. Important concepts include morphine metabolism to morphine-6-glucuronide, prolonged effects in renal impairment, and complications such as aspiration and pulmonary edema. Mastery of these points improves clinical decision-making, safe dispensing, and patient counseling. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which triad most characteristically describes acute morphine (opioid) poisoning?
- Fever, tachycardia, hypertension
- Respiratory depression, miosis, altered consciousness
- Diarrhea, lacrimation, mydriasis
- Rash, hypotension, cough
Correct Answer: Respiratory depression, miosis, altered consciousness
Q2. The primary receptor responsible for morphine’s analgesic and respiratory depressant effects is:
- Kappa opioid receptor
- Delta opioid receptor
- Mu opioid receptor
- Sigma receptor
Correct Answer: Mu opioid receptor
Q3. Which metabolite of morphine is pharmacologically active and can accumulate in renal failure?
- Morphine-3-glucuronide (M3G)
- Morphine-6-glucuronide (M6G)
- Normorphine
Correct Answer: Morphine-6-glucuronide (M6G)
Q4. The most immediate life‑threatening effect of severe morphine overdose is:
- Renal failure
- Seizures
- Respiratory arrest from respiratory depression
- Hepatic necrosis
Correct Answer: Respiratory arrest from respiratory depression
Q5. Which clinical sign helps differentiate opioid poisoning from benzodiazepine intoxication?
- Hyperreflexia
- Miosis (pinpoint pupils)
- Ataxia
- Fever
Correct Answer: Miosis (pinpoint pupils)
Q6. Initial emergency management of a patient with suspected morphine overdose includes:
- Immediate dialysis
- Administering naloxone and securing the airway
- High-dose benzodiazepines
- Administration of flumazenil
Correct Answer: Administering naloxone and securing the airway
Q7. A recommended initial intravenous naloxone dose for an adult in emergency settings is commonly:
- 0.01 mg
- 0.04–0.4 mg (titrated) or 0.4–2 mg depending on protocol
- 10–20 mg
- 50 mg
Correct Answer: 0.04–0.4 mg (titrated) or 0.4–2 mg depending on protocol
Q8. If a patient responds to naloxone but redevelops respiratory depression later, the best next step is:
- Give benzodiazepines
- Start a naloxone infusion or repeat doses and monitor closely
- Administer activated charcoal only
- Discharge home with opioid cessation advice
Correct Answer: Start a naloxone infusion or repeat doses and monitor closely
Q9. Which investigation is most useful to assess the severity of opioid-induced respiratory compromise?
- Serum creatinine
- Arterial blood gas (ABG)
- Chest X‑ray immediately
- Electrolyte panel only
Correct Answer: Arterial blood gas (ABG)
Q10. Activated charcoal is most effective for morphine ingestion when given within what time frame?
- Within 1–2 hours of ingestion
- After 24 hours only
- Only if administered before arrival
- Activated charcoal is contraindicated in opioid overdose
Correct Answer: Within 1–2 hours of ingestion
Q11. Which route of naloxone administration is useful for prehospital naloxone when IV access is not available?
- Topical naloxone cream
- Intranasal or intramuscular naloxone
- Oral naloxone tablets
- Rectal naloxone suppositories
Correct Answer: Intranasal or intramuscular naloxone
Q12. Morphine causes miosis via which mechanism?
- Stimulation of sympathetic outflow
- Inhibition of parasympathetic nucleus
- Activation of Edinger-Westphal nucleus via central mu receptors
- Direct action on iris sphincter peripheral receptors only
Correct Answer: Activation of Edinger-Westphal nucleus via central mu receptors
Q13. In renal impairment, morphine toxicity risk increases primarily because:
- Morphine is protein-bound and displaced by uremic toxins
- Active glucuronide metabolites (M6G) accumulate and prolong effects
- Morphine is converted to codeine
- Morphine is rapidly excreted leading to rebound pain
Correct Answer: Active glucuronide metabolites (M6G) accumulate and prolong effects
Q14. Which complication is commonly associated with severe morphine overdose and hypoventilation?
- Severe hyperthermia
- Aspiration pneumonitis and hypoxic brain injury
- Acute pancreatitis
- Hypoglycemia
Correct Answer: Aspiration pneumonitis and hypoxic brain injury
Q15. Which drug interaction increases the risk of profound respiratory depression when combined with morphine?
- Acetaminophen
- Benzodiazepines and other central nervous system depressants
- SSRIs at usual doses
- Proton pump inhibitors
Correct Answer: Benzodiazepines and other central nervous system depressants
Q16. A patient with suspected morphine ingestion is bradycardic and hypotensive. Which immediate supportive measure is indicated?
- Give insulin bolus
- Place patient in Trendelenburg position, give IV fluids, and support airway
- Administer high-dose steroids
- Give oral glucose
Correct Answer: Place patient in Trendelenburg position, give IV fluids, and support airway
Q17. Which laboratory test can provide evidence of opioid exposure though not always required for immediate management?
- Urine toxicology screen for opioids
- Serum troponin
- Serum amylase
- Thyroid function tests
Correct Answer: Urine toxicology screen for opioids
Q18. Reversal of morphine with naloxone may precipitate which complication in chronic opioid users?
- Hypoglycemia
- Acute opioid withdrawal with agitation, vomiting, tachycardia
- Severe hypertension crisis
- Renal colic
Correct Answer: Acute opioid withdrawal with agitation, vomiting, tachycardia
Q19. Which statement about naloxone pharmacology is true?
- Naloxone is a long-acting opioid agonist
- Naloxone is an opioid receptor antagonist with a shorter duration than many opioids
- Naloxone causes miosis
- Naloxone is ineffective intravenously
Correct Answer: Naloxone is an opioid receptor antagonist with a shorter duration than many opioids
Q20. In a patient with mixed overdose (opioids and tricyclic antidepressants), naloxone administration will:
- Reverse both opioid and TCA toxicity
- Only reverse opioid effects; TCA toxicity may persist and require separate management
- Worsen TCA toxicity directly
- Be contraindicated
Correct Answer: Only reverse opioid effects; TCA toxicity may persist and require separate management
Q21. Which sign is NOT typical of opioid toxidrome?
- Hypoventilation
- Miosis
- Hyperreflexia with myoclonus
- Coma
Correct Answer: Hyperreflexia with myoclonus
Q22. For pediatric opioid overdose, which principle is most important?
- Children never require naloxone
- Use weight‑based naloxone dosing and prioritize airway/ventilation
- Give activated charcoal as first-line always
- Observe at home for 48 hours without intervention
Correct Answer: Use weight‑based naloxone dosing and prioritize airway/ventilation
Q23. Continuous naloxone infusion is considered when:
- The patient has persistent or recurrent respiratory depression after repeated boluses
- The patient has mild nausea only
- There is no clinical response to any naloxone bolus
- To prevent opioid withdrawal in chronic pain patients
Correct Answer: The patient has persistent or recurrent respiratory depression after repeated boluses
Q24. Which of the following is a pharmacokinetic property of morphine?
- Extensive hepatic metabolism to glucuronides and limited oral bioavailability
- Primarily exhaled unchanged via lungs
- 100% oral bioavailability
- Metabolized mainly to active catecholamines
Correct Answer: Extensive hepatic metabolism to glucuronides and limited oral bioavailability
Q25. Which clinical scenario suggests the need for mechanical ventilation in morphine poisoning?
- Respiratory rate 6 breaths/min and PaCO2 > 60 mmHg despite naloxone
- Pulse rate 90/min with normal oxygen saturation
- Isolated mild miosis with normal respiration
- Stable vitals after a single naloxone dose with spontaneous respiration
Correct Answer: Respiratory rate 6 breaths/min and PaCO2 > 60 mmHg despite naloxone
Q26. Which precaution is important when administering activated charcoal in opioid-poisoned patients?
- Activated charcoal enhances opioid absorption
- Charcoal is contraindicated if airway is unprotected—ensure airway protection or endotracheal tube
- Charcoal reverses opioid receptor binding
- Charcoal is ineffective for opioids and never used
Correct Answer: Charcoal is contraindicated if airway is unprotected—ensure airway protection or endotracheal tube
Q27. Which feature on chest radiograph may result from severe opioid overdose?
- Pleural effusion only
- Aspiration pneumonitis or pulmonary edema
- Fractured ribs
- Pulmonary embolism sign
Correct Answer: Aspiration pneumonitis or pulmonary edema
Q28. Which statement about naloxone dosing for opioid overdose in the community is correct?
- Intranasal naloxone devices can be lifesaving and are recommended for lay rescuers
- Naloxone should never be used outside hospitals
- Only oral naloxone is effective in the community
- Naloxone is addictive and should not be available to the public
Correct Answer: Intranasal naloxone devices can be lifesaving and are recommended for lay rescuers
Q29. Which monitoring is essential after naloxone reversal of morphine toxicity?
- No monitoring required after one dose
- Continuous respiratory and oxygen saturation monitoring for recurrence of respiratory depression
- Only blood glucose monitoring
- Immediate discharge once awake
Correct Answer: Continuous respiratory and oxygen saturation monitoring for recurrence of respiratory depression
Q30. As future pharmacists, which responsibility is most important to reduce morphine poisoning risk?
- Counsel patients on correct dosing, drug interactions, storage, and opioid safety including naloxone availability
- Never dispense opioids under any circumstance
- Provide opioids without labeling to improve adherence
- Advise doubling dose if pain persists
Correct Answer: Counsel patients on correct dosing, drug interactions, storage, and opioid safety including naloxone availability
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
Mail- Sachin@pharmacyfreak.com