Analgesic Potency | Potent, reference opioid | Less potent | Highly potent | Similar to Fentanyl |
Duration of Action | Moderate (1-2 hours) | Short (10-15 minutes) | Prolonged (2-4 hours) | Very short (3-10 minutes) |
Onset of Action | Rapid (1-2 minutes) | Rapid (1-2 minutes) | Rapid (1-2 minutes) | Rapid (1-2 minutes) |
Dosage per kg (IV) | 1-2 mcg/kg | 5-20 mcg/kg | 0.1-0.4 mcg/kg | 1-2 mcg/kg (induction) |
Blood-Brain Equilibration | Rapid | Rapid | Rapid | Rapid (similar to Alfentanil) |
Metabolism | Hepatic | Hepatic and Renal | Hepatic | Rapid ester hydrolysis |
Clearance | Moderate | Moderate | Moderate | Extraordinary (very rapid) |
Volume of Distribution (Vd) | Large | Moderate | Small | Small (minimal accumulation) |
Context-Sensitive Half-Time | Duration-dependent | Duration-dependent | Duration-dependent | Independent (approx. 4 minutes) |
Clinical Uses | Anesthesia, chronic pain | Anesthesia (rapid onset), sedation | Anesthesia, labor & delivery | Anesthesia, sedation |
Unique Feature | High potency, prolonged action | Rapid onset, short duration | Very high potency | Very rapid onset and offset |
Potential Side Effects | Nausea, vomiting, respiratory depression | Nausea, vomiting, respiratory depression | Nausea, vomiting, respiratory depression | Nausea, vomiting, respiratory depression, hyperalgesia |
Hepatic Dysfunction Impact | May impact clearance | May impact clearance | May impact clearance | Usually not affected |
Renal Dysfunction Impact | May impact clearance | May impact clearance | May impact clearance | Usually not affected |
Intraoperative Dosing Versatility | May require accumulation time | Rapid onset and offset | Requires accumulation time | Rapid titration to desired effect |
Risk of Accumulation | Yes | Yes | Yes | Minimal or none |