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  Background & Objectives: Cesarean section is one of the most common surgeries in women. In developed countries the rate of cesarean section is reported to be 21.2%. In Iran, the rate of cesarean section is even higher than the international norms. In a study in Ardabil, in 2001, cesarean section rate came out to be 42.86%. Postoperative pain after cesarean is one of the complications that all mothers experience in one-way or another. Besides bothering mother it can disorder newborn feeding, ambulation of mother and bonding between newborn and mother if it is not controlled effectively. This study was conducted to compare the effect of intramuscular Methadone and Diclofenac suppository for pain relief after cesarean section in Alavi hospital, Ardabil.

  Methods: This study was a double blind clinical trial. 56 women who experienced cesarean section for the first time were randomly divided into two groups. Diclofenac suppository (100 mg every 8hr) was given to first group and Methadone (5 mg every 8hr) was injected to the second group for 24 hours. Then, the severity of pain was measured with numerical scoring in serial postoperative visits. The data were analyzed by SPSS software using descriptive and analytical statistics such as chi-square and ANOVA.

  Results: The findings indicated that the severity of pain in 2^nd, 3^rd and 4^th postoperative visits was significantly lower in patients who received Diclofenac suppositories than the other group (p<0.05). But overall, there was no statistically significant difference between the pain severity in Methadone receiving group (Mean & SD= 5.85 ± 3.5) and Diclofenac receiving group (Mean & SD= 6.46 ± 2.9).

  Conclusion: There was no significant difference between Diclofenac suppository and Methadone in terms of decreasing the postoperative pain after cesarean section. However, regarding the restrictions in the use of opioids, Diclofenac can be a suitable replacement for these drugs.

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Background & objectives: The purpose of this study was to show the dose response relationship of anti-inflammatory effect of methylsulfonylmethane (MSM) on carrageenan induced rat paw edema as an acute model of inflammation.
Methods: A total of 54 male, Sprague-Dawley rats, weighing 180-190 g, were used. One hundred, 200, 400, 800 and 1200 mg/kg of MSM were administered intraperitoneally to the rats 30 minutes before induction of paw edema with injection of 0.1% carrageenan. Diclofenac was used as a control drug. Rats were divided into three groups: MSM, diclofenac and normal saline, and their paw tissue were collected for the study of inflammatory and oxidative markers (MDA, GSH, TNF-α and IL-1 β). The relationship between the different concentrations of MSM and decrease in rat paw edema was calculated using a simple Emax model.
Results: the ED₅₀ value for effect of MSM on carrageenan induced rat paw edema was 193±9.7 mg/kg. A significant reduction in paw edema following administration of MSM at 200, 400, 800 and 1200 mg/kg was observed, but statistical analysis did not reveal any significant reduction in paw edema after administration of 100 mg/kg. MSM did not show statistically significant difference from control group in tissue level of GSH, but it was able to decrease MDA level significantly. MSM was able to significantly alleviate IL-1 β and TNF-alpha tissue levels.
Conclusion: The recommended anti-inflammatory dosing range of MSM is 200-800 mg/kg for pharmacological studies in rats and the average appropriate dose is 400 mg/kg. Also, it seems that anti-inflammatory effect of MSM is more profound than its anti-oxidant effects.