In adults with suspected opiate overdose causing respiratory depression, what is the initial Naloxone dose and possible repeat dosing if needed?

• A. 0.5 mg IM/IN/IV/IO; may repeat 0.5 mg every two to three minutes; maximum total 10 mg.
• B. 1 mg IV bolus; may repeat every three minutes; maximum 5 mg.
• C. 2 mg IM; repeat as needed every five minutes; maximum 20 mg.
• D. 0.25 mg IV; repeat 0.25 mg every minute; maximum 2 mg.

Answer: (A)

Naloxone should be given in a titrating, small-dose approach to reverse opioid-induced respiratory depression while avoiding sudden withdrawal or excessive sympathetic activation. The key idea is to restore adequate breathing by giving just enough naloxone to improve ventilation, then reassessing before giving more.

Starting with a low dose of 0.5 mg delivered by IM, intranasal, IV, or intraosseous routes allows rapid assessment of response. If breathing and mental status don’t improve, you can give another 0.5 mg dose at 2–3 minute intervals, continuing to titrate to effect. This stepwise strategy reduces the risk of overshooting and precipitating withdrawal, especially in opioid-tolerant patients, while ensuring you can reach sufficient reversal for longer-acting opioids if needed. A common upper limit used in many protocols is a total of about 10 mg, which provides a safety margin for cases involving potent or long-acting opioids.

Options that start with higher single doses or use longer intervals aren’t as well aligned with this titration approach. Large upfront doses can provoke abrupt withdrawal and serious cardiovascular effects, and slower or smaller dosing schemes may fail to reverse respiratory depression promptly. The 0.5 mg initial dose with 0.5 mg repeats every 2–3 minutes up to about 10 mg best balances rapid reversal with controlled dosing.