A 32-year-old man with opioid use disorder receives IV naloxone for respiratory depression after heroin overdose. He regains consciousness with RR 14/min within 2 minutes. After 45 minutes, he becomes drowsy again with respiratory rate 8/min. What is the most appropriate explanation?
- A The half-life of naloxone is shorter than that of heroin, causing recurrence of respiratory depression ✓
- B Naloxone causes rebound respiratory depression after its effect wears off
- C The patient has aspirated and developed chemical pneumonitis
- D The patient has developed acute pulmonary edema from naloxone
Correct answer: A. The half-life of naloxone is shorter than that of heroin, causing recurrence of respiratory depression
Explanation
Naloxone has a half-life of approximately 30-90 minutes, which is shorter than the duration of action of most opioids including heroin (4-6 hours). This mismatch causes 'renarcotization' where respiratory depression recurs as naloxone is metabolized. The correct management is continuous naloxone infusion or repeat boluses rather than single-dose administration.
Reference: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 13th ed.
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Written and medically reviewed by the StethoPrep medical team.