Opioids
Mechanism of Action
Pharmacokinetic Considerations
Side Effects and Contraindications
Drugs in this Group
Morphine
Buprenorphine
Butorphanol
Pethidine
Methadone
Fentanyl
Etorphine
Opioid Antagonists
Naloxone is an antagonist to endogenous opioids. It is frequently used in human medicine to antagonise opioid narcotics in the incidence of overdose. Naloxone may be administered intravenously, intramuscularly, intrathecally or subcutaneously. It has a short duration of action (1-2 hours) and so repeated administrations may be necessary.