For suspected fentanyl overdose in adults, what Naloxone regimen is recommended as an initial loading dose followed by additional dosing if needed?

• A. Start with a 1 mg IN Naloxone loading dose; no further dosing is recommended.
• B. A loading dose of 4 mg IN Naloxone, with additional 0.5 mg IM/IN/IV/IO every two to three minutes if needed; maximum total 10 mg.
• C. 2 mg IV bolus; no repeated dosing.
• D. Naloxone is not indicated in suspected fentanyl overdose.

Answer: (B)

When treating suspected fentanyl overdose, you reverse with naloxone but must do it in a way that matches fentanyl’s power and duration. Fentanyl can cause profound, rapidly evolving respiratory depression, and naloxone’s effects can wear off before fentanyl does, so you don’t rely on a single fixed dose. Instead, give a sufficiently large loading dose to start reversing symptoms, then titrate with small additional doses to maintain reversal while you reassess the patient.

A loading dose of 4 mg given intranasally provides a strong, rapid reversal signal in most adults with fentanyl exposure. If breathing and mentation don’t improve, you continue with small supplemental doses: 0.5 mg delivered by any approved route (IM, IN, IV, or IO) every two to three minutes, up to a total maximum of 10 mg. This titration approach helps you achieve adequate reversal without overshooting too quickly, reduces the risk of agitation or withdrawal, and accounts for the possibility of re-narcotization as fentanyl’s effects outlast naloxone.

Other regimens that start with smaller doses and stop after one dose may fail to reverse severe respiratory depression, and giving no naloxone at all is unsafe. The chosen plan—initial 4 mg intranasal, then small, repeated doses as needed up to a 10 mg total—best balances rapid, effective reversal with careful, ongoing assessment.