• Created from a minor structural changes to opioid the agonists.
• A substitution of a alkyl group for a methly group creates an antagonist.
• Antagonists displace opioid agonists from mu receptors.

• Derivative of oxymorphone
• no agonist properties
• high antagonist affinity for the mu receptors
• moderate antagonistic affinity for the kappa receptors.
• Metabolized in the liver

• Tx of opioid-induced depression of ventilation
• Tx of opioid-induced depression of ventilation in neonates.
• Tx of pts at risk of deliberate opioid overdose
• Used to detect suspected physical  dependence to opioids.

Dose: Titrate 1-4mcg/kg to desired effect

Onset of Action: IV 1-2min IM/SQ/ETT 2-5min

DOA-Short 30-45min

Clinical Implications: You may need to redose this patient r/t resp. depression and short DOA.

• Reversal of analgesia
  • titrate 40-100mcg at a time to prevent
• N/V with rapid administration
• Awakening
• Sympathetic nervous system activity
• Withdrawal syndrome

Equipotent to naloxone

Dose:15-25mcg IV every 2-5min

Duration of action-longer

Side Effects- same as naloxone