Analgesic and antisympathetic effects of clonidine in burn patients, a randomized, double-blind, placebo-controlled clinical trial

Objectives: Unlike most other Analgesic drugs, α2 adrenoceptor agonists are capable of producing analgesia. The aim of this study was to evaluate the Analgesic and antisympathetic effects of clonidine, an α2 adrenoceptor agonist in burn patients.
Materials and Methods: This randomized, double-blind, placebo-controlled clinical trial performed on one hundred burn patients in Zarea Hospital, Mazandaran, Iran from august 2004 to July 2005. All patients divided in two groups. Case group (n=50) received oral clonidine, 3.3μg/kg TDS and controls (n=50) received placebo. Heart rate and systolic blood pressure and pain severity Visual analogue score (VAS), were recorded after clonidine administration. Statistical analysis was done by means of Mann Witney U test.
Results: 50 patients (mean age 28.96±10 years) in case group, and 50 patients (mean age 27.60±11.4 years) in control group were studied. VAS pain scores and heart rate in the clonidine group were significantly lower than the control group (P< 0.0001, P< 0.02).there were no significant difference in systolic blood pressure between the two groups on the first and second day but on third day the systolic blood pressure in clonidine group, was lower than controls significantly (P=0.002).
Conclusion: This study demonstrates that the use of oral clonidine affects the hemodynamic response to pain in burn patients. Our study demonstrated that clonidine can produce good analgesia and decreased in sympathetic over activity in burn patients, and also reduce opioid dose requirements.