A 28-year-old woman from Mumbai presents to the emergency department 2 hours after injecting heroin. She is drowsy, with pinpoint pupils, respiratory rate 8/min, oxygen saturation 88% on room air, and blood pressure 100/65 mmHg. She is unresponsive to verbal stimuli. Her urine drug screen is positive for opioids. What is the immediate management priority?

Explanation

## Acute Opioid Overdose Management **Key Point:** Naloxone is a competitive opioid antagonist that rapidly reverses opioid-induced respiratory depression and is the first-line emergency treatment for opioid overdose. ### Immediate Management Algorithm ```mermaid flowchart TD A[Opioid overdose: RR < 12, pinpoint pupils, altered consciousness]:::urgent A --> B[Secure airway if needed, give 100% O₂]:::action B --> C[Administer IV naloxone 0.4-0.8 mg]:::action C --> D{Response in 2-3 min?}:::decision D -->|Yes: RR > 12, alert| E[Monitor for 4+ hours, repeat naloxone if relapse]:::action D -->|No| F[Repeat naloxone 0.4-0.8 mg every 2-3 min, max 10 mg]:::action F --> G{Improvement?}:::decision G -->|Yes| E G -->|No: Consider non-opioid cause| H[Intubate and ventilate]:::action ``` ### Naloxone Pharmacology | Property | Detail | |----------|--------| | **Mechanism** | Competitive antagonist at μ, δ, κ opioid receptors | | **Onset** | IV: 1–2 minutes; IM: 5–10 minutes | | **Duration** | 30–90 minutes (shorter than most opioids) | | **Dose** | 0.4–0.8 mg IV/IM, repeat every 2–3 min up to 10 mg | | **Contraindication** | None in overdose (life-saving) | | **Adverse effect** | Acute withdrawal syndrome (agitation, sweating, tachycardia, hypertension) | **High-Yield:** Naloxone is ALWAYS the first-line agent in opioid overdose, regardless of diagnostic uncertainty. It has no abuse potential and no respiratory depression ceiling — it is safe to give even if opioid overdose is suspected but not confirmed. ### Clinical Pearl This patient has **classic opioid overdose triad**: pinpoint pupils, respiratory depression (RR 8), and altered consciousness. Her SpO₂ of 88% indicates hypoxaemia from hypoventilation — immediate naloxone is life-saving. **Warning:** Naloxone has a shorter half-life (30–90 min) than heroin metabolites. After initial reversal, the patient may relapse into overdose 1–2 hours later. She must be monitored for at least 4 hours and given a repeat dose or continuous infusion if needed. ### Why Intubation Is NOT First-Line While bag-mask ventilation and oxygen are important, **naloxone reverses the cause** and restores spontaneous respiration within minutes. Intubation is a bridge if naloxone fails or if airway is unprotected; it is not the priority when a specific antagonist is available. **Mnemonic: NALOXONE SAVES** — Naloxone: Antagonist, Lifesaving, Opioid-specific, Xeric (dry) mouth, Onset 1–2 min, No abuse potential, Emergency drug.