Opioid Antagonists

What is the prototype?

Naloxone

• Given IV, IM, SC, endotracheal, sublingual, and nasal

• “Lifting the wet blanket”

Why is it prescribed?

Emergency reversal of opiate medication, usually for overdose or suspected overdose

How does it work?

Binds to opioid receptors without activating them, blocking the effects of those receptors and reversing the effects of narcotic drugs

What happens if there is too much drug effect?

Nothing, but when this medication is administered it immediately reverses opiate effects and activates the SNS

• So, patients are not happy after it’s administered as they have tachycardia, sweating, GI upset, anxiety, and HTN

What is important to remember about this medication (5)?

• No contraindications for this emergency medication

• The half-life is relatively short, around 1 hour

  • Some long-acting opioids can remain in the body for over 12 hours, which may necessitate additional doses of naloxone and close monitoring

• Naloxone can decrease the effectiveness of opioids for several hours after administration, depending on the dosage

• Use caution if the patient has a diagnosis of acute narcotic abstinence syndrome

• Monitor for the need for additional doses, hypertension, and heart rate

What do you need to tell a patient taking this medication?

Have this medication available if the risk of opiate overdose is high