Opioids
- Percocet: Oxycodone-Acetaminophen
- Vicoden/Norco/Lortab: Hydrocodone-Acetaminophen
- Oxycontin/Roxicodone: Oxycodone
- Demerol: Meperidine
- Dilaudid: Hydromorphone
Mechanism of Action
Act as agonists at opioid receptors (μ = β-endorphin, δ = enkephalin, κ = dynorphin) to modulate synaptic transmission—open K+ channels, close Ca2+ channels -> ↓ synaptic transmission. Inhibit release of ACh, norepinephrine, 5-HT, glutamate, substance P
Clinical Use
Pain, cough suppression (dextromethorphan), diarrhea (loperamide, diphenoxylate), acute pulmonary edema, maintenance programs for heroin addicts (methadone, buprenorphine + naloxone).
| Drug | Class | MOA | Dose | Onset | Duration | Elimination |
|---|---|---|---|---|---|---|
| Fentanyl | Synthetic opioid
Intermediate acting |
Mu and kappa opioid receptor | 1-20 μg/kg IV | IV 4-6 min | IV 30-45 min | Hepatic |
| Sufentanil | Synthetic opioid
Intermediate acting |
Mu and kappa opioid receptor | 0.3-1 μg/kg IV | 1-2 min | 20-40 min | Hepatic |
| Remifentanil | Synthetic opioid
Ultra-short acting |
Mu and kappa opioid receptor | Induction: 0.3-1 μg/kg
Maintenance: 0.1-1 μg/kg/min Sedation: 0.05-0.1 μg/kg /min |
Bolus: 1-1.5 min
Infusion: 3-5 min |
5-10 min | Esterase |
| Alfentanil | Synthetic opioid
Short-acting |
Mu and kappa opioid receptor | 5-50 μg/kg | 1-2 min | 20 min | Hepatic |
| Morphine | Opioid analgesic
Long acting |
Mu and kappa opioid receptor | Adult: 2.5-15 mg IV/IM/SC
Peds: 0.05-0.2 mg/kg |
IV 5-10 min
IM 15-30min |
2-5 hrs IV/IM/SC | Hepatic |
| Meperidine | Opioid analgesic
Long acting |
Mu and kappa opioid receptor | IV 25-75 mg
IM 0.5-2 mg/kg |
IV 3-8 min
IM 10-20 min |
2-4 hr | Hepatic |
| Naloxone | Opioid antagonist | Agonist at opioid receptor | Post-operative: 0.5-1 μg/kg boluses, q -23min (max 1-2 μg/kg IV) | 1-2 min | 30-60 min | Hepatic |
| Drug | Clinical Use |
|---|---|
| Methadone | Long-acting oral opiate used for heroin detoxification or long-term maintenance therapy |
| Suboxone (Buprenorphine + Naloxone) | Sublingually, buprenorphine (partial agonist) is absorbed and used for maintenance therapy. Naloxone (antagonist, not orally bioavailable) is added to lower IV abuse potential. |
| Naltrexone | Long-acting opioid antagonist used for relapse prevention once detoxified. |
Clinical Opiate Withdrawal Scale
