IRCT201710059014N191 IRCT 2017-10-05 Vice-chancellor for Research and Technology, Hamadan University of Medical Sciences Comparison of the effect of Acetaminophen, Pethidine and Ibuprofen on pain relief in patients with acute cholecystitis Comparison of the effect of Acetaminophen, Pethidine and Ibuprofen on pain relief in patients with acute cholecystitis: a triple blind randomized clinical trial 2017-10-23 anticipated 90 Complete https://irct.ir/trial/9629 interventional Randomization: Randomized, Blinding: Triple blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Other design features: Randomization: The patients will be randomly assigned to intervention and control groups using block randomization. Blinding: Patients will be unaware of the type of intervention. The physician who will examine the patients will not be aware of the intervention. The analyzer will be unaware of the type of interventions. Therefore, the trial will be run as triple blind, Randomization description: The patients will be randomly assigned to intervention and control groups using block randomization. For this purpose, we will prepare four sheets of paper, writing on two sheets the name of the intervention and on the other two sheets the name of the control. The paper sheets will be pooled, placed in a container, and randomly drawn one at a time for each patient without replacement until all six sheets are drawn. The four paper sheets will be then placed back into the container, and this action repeated until the sample size is reached, Blinding description: The shape of the medications will be perfectly the same. Therefore, patients will be unaware of the type of intervention. The physician who will examine the patients will not be aware of the intervention. The analyzer will be unaware of the type of interventions Therefore, the trial will be run as triple blind. 2 Acute cholecystitis. Intervention 1: Intervention group 1: Intravenous infusion of 10 mg/kg Acetaminophen in 100 ml normal saline within 30 minutes single dose. Intervention 2: Intervention group 2: Intravenous infusion of 10 mg/kg Ibuprofen in 100 ml normal saline within 30 minutes single dose. Intervention 3: Intervention group 3: Intravenous infusion of 1 mg/kg Pethidine in 100 ml normal saline within 30 minutes single dose. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is It depends on the situations and the results of the study as well as approval of the financial supporting organization.