Letrozole versus Tamoxifen in Treatment of Clomiphene Citrate Resistant Polycystic Ovarian Syndrome Enliven Archive | www.enlivenarchive.org 1 2014 | Volume 1 | Issue 1 * Corresponding author: Mohamed Nabih EL-Gharib, MB, BCH (Hon), DGO, DS, MD (OB/GYN), Professor of Obstetrics & Gynecology, Faculty of Medicine, Tanta University, Tanta, Egypt, E-mail: mohgharib@hotmail. com Citation: EL-Gharib MN, Mahfouz AE, Farahat MA (2014) Letrozole versus Tamoxifen in Treatment of Clomiphene Citrate Resistant Polycystic Ovarian Syndrome Enliven: Gynecol Obestet 1(1):003 Copyright: @ 2014 Dr. Mohamed Nabih EL-Gharib. This is an Open Access article published and distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited. Introduction Polycystic ovary syndrome (PCOS) is one of the most common causes of an ovulatory infertility which affects 4-7% of women worlwide. It is by far the most common cause of hyperandrogenic an ovulatory infertility and was described more than half a century ago, the underlying cause of this disorder is still uncertain [1]. The therapeutic strategies for CC-resistant patients include the addition of corticosteroid such as: dexamethasone, [2] extended duration of clomiphen, [3] the use of aromatase inhibitors, [4] laparoscopic ovarian drilling, or in vitro fertilization [5]. Aromatase is a cytochrome P450 (CYP450) hemoprotein - containing enzyme that catalyses the conversion of androstenedione and testosterone via hydroxylation steps to estrone and estradiolrespectively [6]. Before the onset of letrozole administration, early pregnancy should be ruled out, since information regarding possible teratogenic effects of this drug is limited [7]. Received Date: 6 th August 2014 Accepted Date: 4 th September 2014 Published Date: 10 th September 2014 Research Article Enliven: Gynecology and Obstetrics EL-Gharib MN *1 , Mahfouz AE 2 , and Farahat MA 3 1 Professor of Obstetrics & Gynecology, Faculty of Medicine, Tanta University, Tanta, Egypt 2 Professor of Obstetrics & Gynecology, Faculty of Medicine, Tanta University, Tanta, Egypt 3 Lecturer of Obstetrics & Gynecology Faculty of Medicine, Tanta University, Tanta, Egypt www.enlivenarchive.org Abstract Objective The objective of this prospective randomized study was to make a comparison between Letrozole and Tamoxifen (TMX) effects in ovulation induction in clomiphene (CC)-resistant women with polycystic ovarian syndrome (PCOS). Material and Methods The study comprised a total of 60 infertile women (175 cycles) with CC-resistant PCOS selected from the clinics of the Department of Obstetrics and Gynecology of Tanta University Hospital. Patients were randomized to treatment with 2.5mg of letrozole daily (30 patients, 86 cycles) or 20mg of tamoxifen daily (30 patients, 89 cycles) for 5days from day 5 of menses and 10000 IU hCG when mature follicles becomes ≥18 mm in diameter. Results The total number of follicles was more in the letrozole group (≥18mm). The endometrial thickness at the time of hCG administration was significantly high (p<0.05, at 95% CI) in the letrozole group than that of tamoxifen group (10.2 ± 0.7 vs. 9.1 ± 0.2mm). Ovulation occurred in 23.33% in the letrozole group and in 8.89% in the tamoxifen group, whereas pregnancy occurred in 5.56% in the letrozole group and in 2.22% in the tamoxifen group. Conclusion Both letrozole and TMX should be considered asoptional therapy for CC-resistant women. In addition, letrozole was super to TMX in achieving a higher pregnancy and ovulation induction rate, and lesser side effects than tamoxifen. Keywords Letrozole; Tamoxifen; Clomiphene resistance; Infertility; Oligomenorrhea; Polycystic ovarian syndrome; Ovulation induction