Effects of Clonidine as premedication on plasma renin activity, serum and urine electrolytes and bodyfluids in general anesthesia

Objectives: Clonidine is a relative alpha2 agonist that΄s used as a premedicative drug in anesthesia in recent years. The aim was to asses the effect of oral clonidine as premedicative drug on 24 hours urine output, urine specific gravity, serum and urine electrolyte level and renin plasma activity Method: A randomized double blind controlled clinical trial was performed in Asali hospital Khoramabad-Iran during 2004. Sixty patients in ASA class 1 and 2, were randomly selected and divided into two groups. One group received clonidine tablet and control group received placebo tablet, orally, ninety minutes before induction of general anesthesia for cystocel-rectocel perineorraphy surgery. In this study we took blood and urine samples for laboratory measurementsbefore as well as 6 hours after taking the tablets. Differences between two groups were analyzedby students T-test. Results: Significant increase in 24 hours urine output (P = 0.001) was seen in clonidine group, compared to control group. Clonidine group had higher urine electrolyte levels (P 0.05) however, no differences were seen in blood electrolyte level (P 0.05). Urine specific gravity was lower in clonidine group (P 0.05). Significant decrease in plasma renin activity was seen in clonidine group (P = 0.001). Conclusion: This study suggested that clonidine is a safe premedication drug in anesthesia and does not change the serum electrolytes level.