A Randomized Placebo-controlled Trial of Clonidine Impact on Sedation of Mechanically Ventilated ICU Patients

Clonidine has sedative and analgesic properties. Randomized studies examining these properties in mechanically ventilated ICU patients are scarce. This study was designed to assess the impact of clonidine on sedative agent use in mechanically ventilated patients. In a prospective, randomized, double blind, placebo-controlled study in a general ICU of a university medical center in Tehran, Iran, 40 patients, over 18 years on mechanical ventilation for 3 days or more randomized into 2 equal groups of clonidine and placebo. Clonidine arm received usual sedation and enteral clonidine 0.1 mg TID and escalated to 0.2 mg TID on the second day if hemodynamics remained stable. Ramsay Sedation Score was used to assess sedation. Opioids and midazolam were used in all patients. 10 patients in clonidine and 3 in placebo arms had history of drug abuse (P = 0.018). The mean of sedatives used in the clonidine/placebo arms (mg/day) were; MED (Morphine Equivalent Dose) 91.4 ± 97.9/112.1 ± 98.8 P=0.39, midazolam 7.1 ± 7.9/8.3 ± 9.2 P=0.66 and propofol 535.8 ± 866.7/139.1 ± 359.9 P=0.125. After adjusting for addiction and propofol, clonidine reduced MED use by 79.6 mg/day (P=0.005) and midazolam by 5.41 mg/day (P = 0.05). Opioids and midazolam need reduced by clonidine co-administration regardless of history of drug abuse. Acceptable side effect profile and the lower cost of clonidine could make it an attractive adjunct to sedative agents in ICU.