Letrozole or clomiphene citrate as first line for anovulatory infertility: a debate

Mohan S Kamath, Korula George, Mohan S Kamath, Korula George

Abstract

Clomiphene citrate has been traditionally used as the drug of choice in treating women with anovulatory infertility. In the last decade letrozole, an aromatase inhibitor has emerged as alternative ovulation induction agent. Literature confirms that letrozole has a definitive role in anovulatory women who have not responded to the clomiphene therapy. However its role as an alternative to clomiphene as first line therapy continues to be debated. Although it is probable that the overall benefits of letrozole surpass clomiphene citrate, currently available data does not confirm this view. There is need for large well-designed trials.

References

    1. Homburg R. Clomiphene citrate - end of an era? A mini review. Hum Reprod. 2005;20:2043–2051. doi: 10.1093/humrep/dei042.
    1. Gysler M, March CM, Mishell DR Jr, Bailey EJ. A decades experience with an individualized clomiphene treatment regimen including its effect on the post coital test. Fertil Steril. 1982;37:161.
    1. Mitwally MFM, Casper RF. Use of an aromatase inhibitor for induction of ovulation in patients with an inadequate response to clomiphene citrate. Fertil Steril. 2001;75:305–309. doi: 10.1016/S0015-0282(00)01705-2.
    1. Al-Omari WR, Sulaiman W, Al-Hadithi N. Comparision of two aromatase inhibitors in women with Clomiphene resistant polycystic ovary syndrome. Int J Gynecol Obstet. 2004;85:289–291. doi: 10.1016/j.ijgo.2003.11.010.
    1. Azim A, Oktay K. Letrozole for ovulation induction and fertility preservation by embryo cryopreservation in young women with endometrial carcinoma. Fertil Steril. 2007;88:657–664. doi: 10.1016/j.fertnstert.2006.12.068.
    1. Goswami SK, Das T, Chattopadhyay R, Sawney V, Kumar J, Choudhary K, Chakravarthy BN, Kabir SN. A randomized single - blind controlled trial of letrozole as a low cost IVF protocol in women with poor ovarian response: a preliminary report. Hum Reprod. 2004;19:2031–2035. doi: 10.1093/humrep/deh359.
    1. Holzer H, Casper R, Tulandi T. A new era in ovulation induction. Fertil Steril. 2006;85:277–284. doi: 10.1016/j.fertnstert.2005.05.078.
    1. Young SL, Opashi MS, Fritz MA. Serum concentration of euclomiphene and zuclomiphene across consecutive cycles of clomiphene citrate therapy in anovulatory infertile women. Fertil Steril. 1999;71:639–644. doi: 10.1016/S0015-0282(98)00537-8.
    1. Atay V, Cam C, Muhcu M, Cam M, Karateke A. Comparision of Letrozole and Clomiphene citrate in women with polycystic ovaries undergoing ovarian stimulation. J Int Med Res. 2006;34:73–76.
    1. Bayar U, Basavan M, Coskun A, Gezer S. Use of an aromatase inhibitors in Patient with polycystic ovary syndrome: a prospective randomized trial. Fertil Steril. 2006;86:1447–1451. doi: 10.1016/j.fertnstert.2006.04.026.
    1. Badawy A, Abdul Aal I, Abulatta M. Clomiphene citrate or Letrozole in women polycystic ovarian syndrome: a prospective randomized trial. Fertil Steril. 2009;92:849–852. doi: 10.1016/j.fertnstert.2007.02.062.
    1. Begum Rashida M, Ferdous J, Begum A, Quadir E. Comparison of efficacy or aromatase inhibitor and clomiphene citrate in polycystic syndrome. Fertil Steril. 2009;92:853–857. doi: 10.1016/j.fertnstert.2007.08.044.
    1. Polyzos N, Tsappi M, Mauri D, Atay V, Corinovis I, Casazza G. Aromatase Inhibitors for infertility in polycystic ovary syndrome. The beginning or the end of a new era? Fertil Steril. 2008;89:278–280. doi: 10.1016/j.fertnstert.2007.10.016.
    1. Polyzos N, Tzioras S, Badawy AM, Valachis A, Dritsas C, Mauri D. Aromatase Inhibitors for female infertility: a systemic review of the literature. Reprod Biomed Online. 2009;19:456–471. doi: 10.1016/j.rbmo.2009.06.008.
    1. Sohrabvand F, Ansari S, Bagheri M. Efficacy of combined metformin - letrozole in comparison with metformin - clomiphene citrate in clomiphene resistant infertile women with polycystic ovarian disease. Hum Reprod. 2006;21:1432–1435. doi: 10.1093/humrep/del020.
    1. Sipe CS, Davis WA, Maifeld M, Van Voorhis BJ. A prospective randomized trial comparing anastrozole and clomiphene citrate in an ovulation induction protocol using gonadotrophins. Fertil Steril. 2006;86:1676–1681. doi: 10.1016/j.fertnstert.2006.05.048.
    1. Requena A, Herroro J, Landeras J, Navarro E, Neyro JL, Salvador C, Tur R, Callejo J, Checa MA, Farre M, Espinos JJ, Fabregues F, Grana-Barcia M. Reproductive Endocrinology Interest Group of the Spanish Society of Fertility: Use of letrozole in assisted reproduction: systemic review and metanalysis. Hum Reprod Update. 2008;14:571–582. doi: 10.1093/humupd/dmn033.
    1. .
    1. George SS, George K, Irwin C, Job V, Selvakumar R, Jeyaseelan V, Seshadri MS. Sequential treatment of metformin and clomiphene citrate in clomiphene resistant women with polycystic ovary syndrome: a randomized controlled trial. Hum Reprod. 2003;18:299–304. doi: 10.1093/humrep/deg105.
    1. Amer SA, Li TC, Metwally M, Emarh M, Ledger WL. Randomized controlled trial comparing laparoscopic ovarian drilling with clomiphene citrate as a first line of ovulation induction in women with polycystic ovary syndrome. Hum Reprod. 2009;24:219–225.
    1. Elnashar A, Fouad H, Eldosky M, Saeid N. Letrozole induction of ovulation in women with clomiphene citrate-resistant polycystic ovary syndrome may not depend on the period of infertility,the body mass index, or the luteinizing hormone/follicle-stimulating hormone ratio. Fertil Steril. 2006;85:511–513. doi: 10.1016/j.fertnstert.2005.08.016.
    1. Kamath MS, Aleyamma TK, Chandy A, George K. Aromatase inhibitors in women with clomiphene resistance: a randomized double blind placebo controlled trial. Fertil Steril. 2010;94:2857–2859. doi: 10.1016/j.fertnstert.2010.06.008.
    1. Al-Fadhili R, Sylvestre C, Buckette W, Tan LS, Tulandi T. A randomized trial of super ovulation with two different doses of letrozole. Fertil Steril. 2006;85:161–164. doi: 10.1016/j.fertnstert.2005.07.1283.
    1. Quentero RB, Urban R, Lathi RB, Westphal LM, Dahan MH. A comparison of letrozole to gonadotrophins for ovulation induction, in subjects who failed to conceive with clomiphene citrate. Fertil Steril. 2007;88:879–885. doi: 10.1016/j.fertnstert.2006.11.166.
    1. Casper RF. Letrozole versus clomiphene citrare: which is better for ovulation induction? Fertil Steril. 2009;92:858–859. doi: 10.1016/j.fertnstert.2007.03.094.
    1. Biljan MM, Hemming R, Brassard N. The outcome of 150 babies following treatment with letrozole or letrozole with gonadotrophins. Fertil Steril. 2005;84(Supp 1):O-231. Abstract-1033.
    1. Tulandi T, Martin J, Al-Fadhli R, Kabli N, Forman R, Hitkari J, Librach C, Greenblatt E, Casper RF. Congenital malformations among 911 newborns conceived after infertility treatment with letrozole or clomiphene citrate. Fertil Steril. 2006;85:1761–1765. doi: 10.1016/j.fertnstert.2006.03.014.

Source: PubMed

3
購読する