Aug 8, 2001: What are the indications for naloxone administration?

Naloxone, an opioid antagonist, cannot be administered orally because the liver metabolizes the first dose and there is little drug that reaches the circulation (first-pass effect).  Naloxone is well absorbed IM, SQ, and endotracheally.  The onset of action is one-two minutes following IV administration.  Duration of action is 20-90 minutes.

Heroin abuse is not a major problem in this state, so I am not going to address the administration of naloxone and possible precipitation of narcotic withdrawal.

Naloxone should be administered to all patients with a decreased sensorium.  Although pediatricians are accustomed to administering drugs on a meticulous mg/kg dose, naloxone should not be administered in this fashion.  One is attempting to reverse the effect of a receptor, do dose-response does not apply.  When naloxone is administered, a minimum of 2mg (not 0.2) should be given.  If there is no response, one should consider giving 6-8 more milligrams.  The toxicity of opiates and some nonopiate drugs may be reversed by the administration of hi-dose naloxone.  Some nonopiate drugs may cause the release of endogenous endorphins or there may be receptor cross-reactivity.  Clinical effects of methadone, Darvon, Demerol, Lomotil, clonidine, valproate, ace inhibitors, and benzodiazepines, have improved following the administration of high- dose naloxone.

There are no side effects of high-dose naloxone administration to children.  It is not an analeptic and does not cause hypertension.