Efficacy of melatonin versus clonidine as premedication on the propofol injection pain and salivary kallikrein response to tracheal intubation in adults

ABSTRACT

Ninety patients ASA I or II scheduled to undergo elective surgery had been included in this study. The patients were randomly allocated to receive one of three treatment prior to induction of anaesthesia with propofol. Melatonin group [=30] received 0.1 mg/kg[-1] melatonin, clonidine group [=30] received 5.5 microg/kg[-1] clonidine and control group [=30] received placebo. All premedicants were dissolved in 3 ml syringe and given sublingually 90/min before induction of anaesthesia. After pretreatment the incidence of propofol injection pain was 26.67% [8 of 30] in melatonin treated group. 30% [9 of 30] in the control group. Additionally, both melatonin and clonidine resulted in shifting a considerable number of patients from the category of sever pain towards a lower category of moderate and mild pain. In the current study [SK] levels showed a mirror image elevation resembling that course of elevation of norepinephrine after tracheal intubation. Our result revealed that both melatonin and clonidine were effective in reducing both norepinephrine and [SK] level at 9, 12, 15 and 30 minutes after intubtion compared to placebo. Clonidine reduced norepinephrine and [SK] to a significant level through whole the study compared to melatonin. We can concluded that melatonin could be used safely as a premedicant for reducing the incidence and severity of propofol injection pain and [SK] estimation reflects the sympathetic stimulation state after endotracheal intubtion in adults