naloxone is an opiate antagonist used to reverse the respiratory depressant effects of opiates and opioids such as heroin
it has a short half life of 60-90 minutes which is much shorter than most opiates and thus there is a risk of rebound respiratory depression once it has worn off, and risk of death
the usual preferred aim is to titrate the dose to gain return of adequate spontaneous breathing and airway protection whilst maintaining a level of sedation to avoid premature self-discharge
overdose of long acting opiates such as methadone requires prolonged infusion of naloxone - see methadone overdose
All patients given naloxone should be observed for re-sedation for at least 2 hours (preferably 4-6hrs, and in children, 24hrs) after the last dose and given warning of chance of rebound toxicity
Indications
GCS < 12 AND RR < 8/min in a patient suspected of having opiate toxicity
Usual initial dosing for acute opiate overdose
100 micrograms IV or 400 micrograms I/Nasal, IM or SC (children: 10 microgram/kg to a maximum of 400 micrograms)
rpt as needed every 30-60secs or so, until spontaneously breathing
iv naloxone infusion
100 microgram/hour can be made up of a 2 mg naloxone vial diluted in 100 ml of 0.9% saline and running at 5 ml/hour
start hourly infusion at 2/3rd of the total initial doses of naloxone required in the first 1 hour
in addition, one-half of the initial hour bolus dose should be administered (as a bolus) 15-20 min. after the start of the infusion to prevent a drop in naloxone levels
best way to titrate the naloxone is patient breathing (resp. rate > 12/min) but still sedated to reduce probability of premature absconding patient who will then have a high chance of delayed onset death