A comparison of the effects of clomiphene citrate and the aromatase inhibitor letrozole on superovulation in Asian women with normal ovulatory cycles

References

• Dickey R P, Holtkamp D E. Development, pharmacology and clinical experience with clomiphene citrate. Hum Reprod Update 1996; 2: 483–506
   PubMed Web of Science ®Google Scholar
• Shoham Z. Drugs used for controlled ovarian stimulation. Textbook of assisted reproductive techniques: Laboratory and clinical perspectives. 2nd ed, D K Garder, A Weissman, C M Howles, Z Shoham. Taylor & Francis, London 2004; 519–539
   Google Scholar
• Deaton J L, Gibson M, Blackmer K M, Nakajima S T, Badger G J, Brumsted J R. A randomized, controlled trial of clomiphene citrate and intrauterine insemination in couples with unexplained infertility or surgically corrected endometriosis. Fertil Steril 1990; 54: 1083–1088
   PubMed Web of Science ®Google Scholar
• Glazener C M, Coulson C, Lambert P A, Watt E M, Hinton R A, Kelly N G, Hull M G. Clomiphene treatment for women with unexplained infertility: placebo-controlled study of hormonal responses and conception rates. Gynecol Endocrinol 1990; 4: 75–83
   PubMed Web of Science ®Google Scholar
• Guzick D S, Sullivan M W, Adamson G D, Cedars M I, Falk R J, Peterson E P, Steinkampf M P. Efficacy of treatment for unexplained infertility. Fertil Steril 1998; 70: 207–213
   PubMed Web of Science ®Google Scholar
• Clark J H, Guthrie S C. Agonistic and antagonistic effects of clomiphene citrate and its isomers. Biol Reprod 1981; 25: 667–672
   PubMed Web of Science ®Google Scholar
• Clark J H, Markaverich B M. The agonistic–antagonistic properties of clomiphene: a review. Pharmacol Ther 1981; 15: 467–519
   PubMedGoogle Scholar
• Dickey R P, Olar T T, Taylor S N, Curole D N, Matulich E M. Relationship of endometrial thickness and pattern to fecundity in ovulation induction cycles: effect of clomiphene citrate alone and with human menopausal gonadotropin. Fertil Steril 1993; 59: 756–760
   PubMed Web of Science ®Google Scholar
• Haritha S, Rajagopalan G. Follicular growth, endometrial thickness, and serum estradiol levels in spontaneous and clomiphene citrate-induced cycles. Int J Gynaecol Obstet 2003; 81: 287–292
   PubMed Web of Science ®Google Scholar
• Sereepapong W, Suwajanakorn S, Triratanachat S, Sampatanukul P, Pruksananonda K, Boonkasemsanti W, Reinprayoon D. Effects of clomiphene citrate on the endometrium of regularly cycling women. Fertil Steril 2000; 73: 287–291
   PubMed Web of Science ®Google Scholar
• Acharya U, Irvine D S, Hamilton M P, Templeton A A. The effect of three anti-oestrogen drugs on cervical mucus quality and in-vitro sperm–cervical mucus interaction in ovulatory women. Hum Reprod 1993; 8: 437–441
   PubMed Web of Science ®Google Scholar
• Marchini M, Dorta M, Bombelli F, Ruspa M, Campana A, Dolcetta G, Radici E. Effects of clomiphene citrate on cervical mucus: analysis of some influencing factors. Int J Fertil 1989; 34: 154–159
   PubMedGoogle Scholar
• Thompson L A, Barratt C L, Thornton S J, Bolton A E, Cooke I D. The effects of clomiphene citrate and cyclofenil on cervical mucus volume and receptivity over the periovulatory period. Fertil Steril 1993; 59: 125–129
   PubMed Web of Science ®Google Scholar
• Lamb H M, Adkins J C. Letrozole. A review of its use in postmenopausal women with advanced breast cancer. Drugs 1998; 56: 1125–1140
   PubMed Web of Science ®Google Scholar
• Buzdar A U, Robertson J F, Eiermann W, Nabholtz J M. An overview of the pharmacology and pharmacokinetics of the newer generation aromatase inhibitors anastrozole, letrozole, and exemestane. Cancer 2002; 95: 2006–2016
   PubMed Web of Science ®Google Scholar
• Bulun S E, Fang Z, Imir G, Gurates B, Tamura M, Yilmaz B, Langoi D, Amin S, Yang S, Deb S. Aromatase and endometriosis. Semin Reprod Med 2004; 22: 45–50
   PubMed Web of Science ®Google Scholar
• Shozu M, Murakami K, Inoue M. Aromatase and leiomyoma of the uterus. Semin Reprod Med 2004; 22: 51–60
   PubMed Web of Science ®Google Scholar
• Mitwally M F, Casper R F. Aromatase inhibitors in ovulation induction. Semin Reprod Med 2004; 22: 61–78
   PubMedGoogle Scholar
• Mitwally M F, Casper R F. Use of an aromatase inhibitor for induction of ovulation in patients with an inadequate response to clomiphene citrate. Fertil Steril 2001; 75: 305–309
   PubMed Web of Science ®Google Scholar
• Mitwally M F, Casper R F. Aromatase inhibition improves ovarian response to follicle-stimulating hormone in poor responders. Fertil Steril 2002; 77: 776–780
   PubMed Web of Science ®Google Scholar
• Mitwally M F, Casper R F. Aromatase inhibition reduces gonadotrophin dose required for controlled ovarian stimulation in women with unexplained infertility. Hum Reprod 2003; 18: 1588–1597
   PubMed Web of Science ®Google Scholar
• Mitwally M F, Casper R F. The aromatase inhibitor, letrozole: a promising alternative for clomiphene citrate for induction of ovulation. Fertil Steril 2000; 74(Suppl 1)535
   Google Scholar
• Fisher S A, Reid R L, Van Vugt D A, Casper R F. A randomized double-blind comparison of the effects of clomiphene citrate and the aromatase inhibitor letrozole on ovulatory function in normal women. Fertil Steril 2002; 78: 280–285
   PubMed Web of Science ®Google Scholar
• Fatemi H M, Kolibianakis E, Tournaye H, Camus M, Van Steirteghem A C, Devroey P. Clomiphene citrate versus letrozole for ovarian stimulation: a pilot study. Reprod Biomed Online 2003; 7: 543–546
   PubMedGoogle Scholar
• Bayar U, Tanriverdi H A, Barut A, Ayoglu F, Ozcan O, Kaya E. Letrozole vs. clomiphene citrate in patients with ovulatory infertility. Fertil Steril 2006; 85: 1045–1048
   PubMed Web of Science ®Google Scholar
• Jennings J C, Moreland K, Peterson C M. In vitro fertilisation. A review of drug therapy and clinical management. Drugs 1996; 52: 313–343
   PubMed Web of Science ®Google Scholar
• Scialli A R. The reproductive toxicity of ovulation induction. Fertil Steril 1986; 45: 315–323
   PubMed Web of Science ®Google Scholar
• Bakos O, Lundkvist O, Wide L, Bergh T. Ultrasonographical and hormonal description of the normal ovulatory menstrual cycle. Acta Obstet Gynecol Scand 1994; 73: 790–796
   PubMed Web of Science ®Google Scholar
• Ecochard R, Marret H, Rabilloud M, Bradai R, Boehringer H, Girotto S, Barbato M. Sensitivity and specificity of ultrasound indices of ovulation in spontaneous cycles. Eur J Obstet Gynecol Reprod Biol 2000; 91: 59–64
   PubMed Web of Science ®Google Scholar
• Casper R F. Aromatase inhibitors in ovarian stimulation. J Steroid Biochem Mol Biol 2007; 106: 71–75
   PubMed Web of Science ®Google Scholar
• Al-Fozan H, Al-Khadouri M, Tan S L, Tulandi T. A randomized trial of letrozole versus clomiphene citrate in women undergoing superovulation. Fertil Steril 2004; 82: 1561–1563
   PubMed Web of Science ®Google Scholar
• Badawy A, Metwally M, Fawzy M. Randomized controlled trial of three doses of letrozole for ovulation induction in patients with unexplained infertility. Reprod Biomed Online 2007; 14: 559–562
   PubMed Web of Science ®Google Scholar
• Biljan M, Tan S L, Tulandi T. Prospective randomized trial comparing the effects of 2.5 and 5.0 mg of letrozole (LE) on follicular development, endometrial thickness and pregnancy rate in patients undergoing super-ovulation. Fertil Steril 2002; 78(Suppl 1)555
   Google Scholar
• Healey S, Tan S L, Tulandi T, Biljan M M. Effects of letrozole on superovulation with gonadotropins in women undergoing intrauterine insemination. Fertil Steril 2003; 80: 1325–1329
   PubMed Web of Science ®Google Scholar
• Mitwally M F, Casper R F. Aromatase inhibition reduces the dose of gonadotropin required for controlled ovarian hyperstimulation. J Soc Gynecol Investig 2004; 11: 406–415
   PubMedGoogle Scholar
• Al-Omari W R, Sulaiman W R, Al-Hadithi N. Comparison of two aromatase inhibitors in women with clomiphene-resistant polycystic ovary syndrome. Int J Gynaecol Obstet 2004; 85: 289–291
   PubMedGoogle Scholar
• Atay V, Cam C, Muhcu M, Cam M, Karateke A. Comparison of letrozole and clomiphene citrate in women with polycystic ovaries undergoing ovarian stimulation. J Int Med Res 2006; 34: 73–76
   PubMed Web of Science ®Google Scholar
• Bayar U, Basaran M, Kiran S, Coskun A, Gezer S. Use of an aromatase inhibitor in patients with polycystic ovary syndrome: a prospective randomized trial. Fertil Steril 2006; 86: 1447–1451
   PubMed Web of Science ®Google Scholar
• Cortinez A, De Carvalho I, Vantman D, Gabler F, Iniguez G, Vega M. Hormonal profile and endometrial morphology in letrozole-controlled ovarian hyperstimulation in ovulatory infertile patients. Fertil Steril 2005; 83: 110–115
   PubMed Web of Science ®Google Scholar
• Mikkelson T J, Kroboth P D, Cameron W J, Dittert L W, Chungi V, Manberg P J. Single-dose pharmacokinetics of clomiphene citrate in normal volunteers. Fertil Steril 1986; 46: 392–396
   PubMed Web of Science ®Google Scholar
• Terakawa N, Shimizu I, Tsutsumi H, Aono T, Matsumoto K. A possible role of clomiphene citrate in the control of pre-ovulatory LH surge during induction of ovulation. Acta Endocrinol (Copenh) 1985; 109: 58–63
   PubMedGoogle Scholar
• Young S L, Opsahl M S, Fritz M A. Serum concentrations of enclomiphene and zuclomiphene across consecutive cycles of clomiphene citrate therapy in anovulatory infertile women. Fertil Steril 1999; 71: 639–644
   PubMed Web of Science ®Google Scholar