title: A Comparative Investigation of the Analgesic Effects of Metamizole and Paracetamol in Rats.
abstract: BACKGROUND
  This study investigated the effects of metamizole and paracetamol on pain and oxidative stress induced by scalpel incision and carrageenan in rats.
  
  
  METHODS
  Total of 144 rats were divided into groups of 12 animals. Six groups each were used for scalpel incision and carrageenan tests. Pain was inflicted by applying a scalpel incision or carrageenan. Pain-created groups by scalpel incision received metamizole (SIM) or paracetamol (SIP) at doses of 250 or 500 mg/kg. Pain-created groups by carrageenan received metamizole (CAM) or paracetamol (CAP) at doses of 250 or 500 mg/kg. Analgesic activity was determined by Basile Algesimeter. The COX-2 and MPO gene expressions were determined, and malondialdehyde and tGSH were measured in rat paws.
  
  
  RESULTS
  In the scalpel incision test, pain was reduced in groups of SIM-250 and SIM-500 in the first hour by 65.2% and 91.3%, respectively, and in the third hour by 51.9% and 77.8%, respectively, compared with the SIC group. In SIP-250 and SIP-500 groups, pain was reduced in the first hour by 43% and 74%, respectively, and by 33.4% and 59.3%, respectively, in the third hour compared with the SIC group. In the carrageenan test, in groups CAM-250 and CAM-500, pain was reduced in the first hour by 72.3% and 86.1%, respectively, and by 65.8% and 71.4%, respectively, in the third hour compared with the CCG group. In groups CAP-250 and CAP-500, pain was reduced in the first hour by 52.8% and 69.4%, respectively, and by 28.6% and 25.8%, respectively, in the third hour compared with the CCG group. Metamizole inhibited COX-2 gene expression at a dose of 500 mg/kg in the carrageenan test. At doses of 250 and 500 mg/kg, metamizole reduced COX-2 and MPO gene expressions and oxidative stress induced by scalpel incision or carrageenan. But both doses of paracetamol were unable to suppress that parameters.
  
  
  CONCLUSIONS
  Our results show that metamizole is more effective than paracetamol for treating surgical trauma-related pain, inflammation, and oxidative stress and hence may be a preferential drug to paracetamol.
authors.affiliation: Department of Anaesthesiology and Reanimation, Faculty of Medicine, Ataturk University , Erzurum , Turkey.
authors.forename: Ilker
authors.initials: I
authors.lastname: Ince
authors.forename: Mehmet
authors.initials: M
authors.lastname: Aksoy
authors.forename: Ali
authors.initials: A
authors.lastname: Ahiskalioglu
authors.forename: Mehmet
authors.initials: M
authors.lastname: Comez
authors.forename: Aysenur
authors.initials: A
authors.lastname: Dostbil
authors.forename: Mine
authors.initials: M
authors.lastname: Celik
authors.forename: Ismayil
authors.initials: I
authors.lastname: Yilmaz
authors.forename: Renad
authors.initials: R
authors.lastname: Mammadov
authors.forename: Hasan
authors.initials: H
authors.lastname: Dogan
authors.forename: Basak
authors.initials: B
authors.lastname: Boztok Ozgermen
authors.forename: Durdu
authors.initials: D
authors.lastname: Altuner
mesh_terms: D000082:Acetaminophen / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology / Q000627:therapeutic use*; D002351:Carrageenan; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004177:Dipyrone / Q000494:pharmacology / Q000627:therapeutic use*; D004353:Drug Evaluation, Preclinical; D005978:Glutathione / Q000378:metabolism; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D010149:Postoperative Pain / Q000188:drug therapy*; D009195:Peroxidase / Q000378:metabolism; D017208:Rats, Wistar
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000082:Acetaminophen; D004177:Dipyrone; D002351:Carrageenan; D009195:Peroxidase; D051546:Cyclooxygenase 2; D005978:Glutathione
keywords: analgesia; carrageenan; metamizole; pain; paracetamol; rats