Background: Epidural injection of the drugs such as opioids has rather been a successful method in controlling post operative pain.

Materials and Methods: In a clinical trial study, 50 Female patients, in a range of 20-40 years old and ASA class I, who were scheduled for gynecologic operation were investigated. They were randomly divided in two groups. Before induction of general anesthesia, an epidural catheter was placed for each patient. Sixty minutes after the end of operation, a 15-ml solution containing 50-microgram clonidine was injected through the epidural catheter in the first group. In the second group, a similar volume solution containing 50- microgram fentanyl was injected. The catheter was removed after all the patients were followed for 4 hours and their pain was assessed by VAS (Visual Analogue Scale) method.

Results: Our findings revealed that the clonidine group had more intense pain; however they had fewer complications than the opioid group.

Conclusion: We concluded that although clonidine might act as an analgesic drug, but epidural injection of a single dose of 50 microgram of the drug could not be effective enough for postoperative analgesia.