Understanding Anesthesiology - The Global Regional Anesthesia ...

Naloxone
Class
Opioid antagonist. Used to counteract the effects of opioids.
Mechanism of Action
Agonist at the opioid receptors.
Dose
For postoperative opioid depression: 1-2 $g/kg IV in 0.5-1 $g/kg boluses, q 2-3 minutes
For neonatal opioid depression: 10 $g/kg, q 2-3 minutes IV. Infusion: 1-5 $g/kg/hr
Onset
1-2 minutes
Duration
30-60 minutes
Elimination
Hepatic
Effects
CNS
Rapid reversal of opioid effect can cause delirium and severe pain.
CVS
When opioid effect is abruptly antagonized there can be significant sympathetic activation
leading to hypertension, tachycardia and in susceptible individuals, myocardial ischemia and
pulmonary edema.
Misc.
Due to the relatively short duration of action of naloxone, “re-narcotization” can be seen when
it is used to treat respiratory depression caused by long acting opioids such as morphine. In
this case, close monitoring is indicated and supplemental doses may be necessary.
Related Glossary Terms
Alfentanil, Apneic threshold, Fentanyl, Meperidine, Morphine Sulfate, Neonatal depression,
Neonatal opioid depression, Opioids, Re-narcotization, Remifentanil, Sufentanil
Index
Find Term
Chapter 3 - General Anesthesia
Chapter 6 - Drug Finder
Chapter 6 - Opioid agonists and antagonists