IRCT201311168768N3 IRCT 2013-12-20 Vice chancellor for Research and Technology, Hamadan University Of Medical Sciences Comparison of diclofenac and acetaminophen in the managment of pain after back surgery. Comparison of diclofenac and acetaminophen combined with patient controlled analgesia, in the managment of pain after laminectomy surgery. 2013-11-22 anticipated 100 Complete https://irct.ir/trial/9258 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment. N/A acute postoperative pain. Intervention 1: Intervention group: Diclofenac suupp 100mg immediately before induction of anesthesia and 12 hours after surgery, infusion of 100 cc normal saline 15 minutes before the end of the surgery and 12 hours after surgery. In recovery an intravenous patient controlled analgesia (IV PCA) pump containing 100 cc normal saline and 20 cc fentanyl (1000µg) will be connected. The pump characteristics: 2 cc continous flow and bolus of 0.5 cc with lockout interval of 15 minutes. In the case of sedation score above 3, IV PCA will be hold and patient will be monitored. In the case of pain score above 4, morphin four miligrams IV will be injected and recorded in the questionare. Intervention 2: Control group: will recieve placebo suppository immediately before induction of anesthesia and 12 hours after surgery, infusion of 1 gram intravenous acetaminophen in 100 cc normal saline 15 minutes before the end of the surgery and 12 hours after surgery. In recovery an intravenous patient controlled analgesia( IV PCA) pump containing 100 cc normal saline and 20 cc fentanyl (1000µg) will be connected. The pump characteristics: 2 cc continous flow and bolus of 0.5 cc with lockout interval of 15 minutes. In the case of sedation score above 3 IV PCA will be hold and patient will be monitored. In the case of pain score above 4, morphin 4 miligrams IV will be injected and recorded in the questionare.