Table 2.
Characteristics of the pharmacological agents used to achieve a moderate level of sedation in gastrointestinal endoscopy (i.v. administration)1
| Agent | Chemical structure | Molecular weight (g/moL) | Onset of action (min) | Duration of action | Elimination half-life | Metabolism/excretion |
| Midazolam | C18H13ClFN3 | 325.78 | 1.0-2.5 | 2-6 h | 1.8-6.4 h | Hepatic and intestinal; excreted in urine |
| Propofol | C12H18O | 178.27 | < 1 | 3-10 min | Triphasic: 2.2 min, 20 min, 8 h | Hepatic; excreted in urine |
| Fentanyl | C22H28N2O | 336.471 | ≤ 1.5 | 1-2 h | 2-7 h | Hepatic; excreted in urine |
| Meperidine | C15H21NO2 | 247.33 | 5 | 2-4 h | 2-7 h | Hepatic; excreted in urine |
1Modified from Manolaraki et al[14].