Comparison study on effectiveness of pentoxifyllin with LD to prevent recurrent endometriosis

Background: About 75% of the symptomatic patients who involved with endometriosis have pelvic pain and dysmenorrhea. Pentoxifyllin is one of the drugs that according to its mechanism could be effective for pain relief of endometriosis which has been used for endometriosis treatment recently. Objective: We conducted a comparative study for detecting the effect of pentoxifylin (as an immonomodelator) in preventing recurrence endometriotic pain with pentoxifylin plus a combined contraceptive pill with low dose estrogen (LD) and also the LD pill alone. Materials and Methods: This was a comparative clinical trial on 83 patients with the chief complaint (CC) of pain (dysmenorrheal /or pelvic pain) and with the end diagnosis of endometriosis, in an operative laparoscopy. Patients, dividing to 3 groups, were treated with pentoxifylin, pentoxifylin+LD and LD alone for 10 months. The severity of pain (dismenorhea and/or pelvic pain) was detected by visual analogue scale (VAS) before and after the treatment. The severity of endometriosis in the patients was: I in class I and II in class II and III in class III. The groups were matched for the pain. The number of the patients in group 1, 2 and 3 were 28, 28 and 27 respectively. Results: The pain was reduced in the groups of pentoxifylin+LD (p < 0.001) and LD alone (p=0.00). The pain relief was not significant in the group of pentoxifylin alone (p=0.136). After treatment, the severity of pain was not significantly different between the LD group and the LD+penthoxyfillin group, but there was difference between these two groups and the group of penthoxyfillin alone. Conclusion: This study showed that penthoxyfillin actually could not have any effect on the pain relief of endometriosis. It also made it clear that penthoxyfillin could not increase the efficacy of LD when used with this medication.