Endometriosis is a painful condition where endometrial tissue grows outside the uterus, which potentially affects a woman's ability to conceive. Recent studies support the influence of the immune system on this disease. Pentoxifylline is an immunomodulator drug (used for effects on the immune system) which may relieve the symptoms of the disease without inhibiting ovulation. It may improve blood flow through blood vessels and, therefore, help with blood circulation because of its anti-inflammatory activity. However, this systematic review of four trials found there was not enough evidence upon which to draw conclusions about the effectiveness and safety of pentoxifylline in terms of fertility and pain relief outcomes in women with endometriosis. At this update in 2011, there was still no evidence of an increase in pregnancy events in the pentoxifylline group compared with placebo.
This review has been updated in 2011. The results of the original review published in 2009 remain unchanged. There is still not enough evidence to support the use of pentoxifylline in the management of premenopausal women with endometriosis in terms of subfertility and relief of pain outcomes.
Endometriosis is a chronic, recurring condition that occurs during the reproductive years. It is characterized by endometrial tissue developing outside the uterine cavity. This endometrial tissue development is dependent on oestrogen produced primarily by the ovaries and, therefore, traditional management has focused on ovarian suppression. In this review we considered the role of modulation of the immune system as an alternative approach. This is an update of a Cochrane Review previously published in 2009 (Lu 2009).
To assess the effects of pentoxifylline, which has anti-inflammatory effects, in subfertile, premenopausal women for the management of endometriosis.
For the first publication of this review we searched the following databases (from inception to December 2008) for trials: Cochrane Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, CINAHL, and PsycINFO. In addition, all reference lists of included trials were searched and experts in the field were contacted in an attempt to locate trials. This search was rerun to 23 November 2011, for this update.
Randomised controlled trials (RCTs) comparing pentoxifylline with placebo or no treatment, medical treatment, or surgery in subfertile, premenopausal women were included.
Two review authors independently selected trials for inclusion, assessed trial risk of bias, and extracted data using data extraction forms. We contacted study authors for additional information and data. The domains assessed for risk of bias were sequence generation, allocation concealment, blinding, incomplete outcome data, and selective outcome reporting. Peto odds ratios (OR) were used for reporting dichotomous data with 95% confidence intervals (CI), whilst mean differences (MD) were expressed for continuous data. Statistical heterogeneity was assessed using the I2 statistic.
Four trials involving 334 participants were included. One RCT [n=34] showed pentoxifylline had no significant effect on reduction in pain (MD -1.60, 95% CI -3.32 to 0.12). There was no evidence of an increase in clinical pregnancy events in the pentoxifylline group compared with placebo (three RCTs [n=67] OR 1.54, 95% CI 0.89 to 266). One RCT studied recurrence of endometriosis [n=88] (OR 0.88,95% CI 0.27 to 2.84). No trials reported the effects of pentoxifylline on the odds of live birth rate per woman, improvement of endometriosis-related symptoms, or adverse events.