effects of oral tizanidine premedication on pain and hemodynamic responses after spinal needle skin puncture

background: although a variety of methods have been suggested to reduce stress, anxiety and pain intensity due to spinal needle skin puncture, their adverse effects restrict theirs widespread administration. in this study we evaluated the effects of oral tizanidine on the reduction of pain caused by spinal needle puncture and hemodynamic responses. methods : in this double blind randomized clinical trial, 52 patients who were scheduled for elective surgeries under spinal anesthesia were recruited. they were randomly allocated in 2 groups of case and control. in the case group 4mg oral tizanidine was administered to patients one hour before surgery while control group received placebo  heart rate, systolic and diastolic blood pressure were recorded  exactly before spinal needle puncture and 1,3 and 5 minutes after spinal anesthesia. results: the mean average of pain score was significantly lower in case group (p< 0.001). also hemodynamic variables, in terms of heart rate and diastolic blood pressure, were statistically different between two groups (p=0.04 and p=0.02); however, the difference between systolic blood pressure was not significant between two groups. conclusion : premedication with 4mg oral tizanidine produced stability in blood pressure and heart rate during surgery and reduced pain intensity caused by needle puncture.