I am writing this article because Letrozole is a very commonly used drug by Infertility Specialists the world over, but unfortunately it has also attracted a lot of controversy and negative publicity. Would like to clear the air on some of the issues involved.
Ovulatory dysfunction is one of the most common causes of reproductive failure in sub fertile and infertile couples. Since the first clinical trial was published in 1961, Clomiphene Citrate (CC) has been the front-line therapy for ovulation induction. Its use quickly expanded to other empiric indications, such as luteal phase defect and the enhancement of fecundity in unexplained infertility. While CC is able to make eggs in 80% of patients, only half that number, or 40% will conceive. This is because CC has certain negative effects on the lining of the womb which hamper the implantation of the fertilized embryo. Failure to respond to CC occurs in up to 20% of cases, which may then require the use of injectable gonadotropins. Clearly, an inexpensive yet equally efficacious oral alternative would be ideal.
Recent research has focused on the successful use of aromatase inhibitors, mainly letrozole, for ovulation induction. We have been incorporating letrozole into treatment plans for appropriately selected patients for quite some time now. In India it is sold as Letroz, Letoval etc. Letrozole is a drug which has conventionally been used for Breast cancer treatment. This is only because Breast cancer requires the female hormone Estrogen for its sustenance and Letrozole is an anti oestrogen drug. It is because of this property that Letrozole can also be used to make eggs grow as in the absence of Estrogen, the hormones FSH and LH start to increase and stimulate the ovaries to make eggs bigger. Letrozole is commonly used in a dosage of 2.5mg twice daily from Day 2 to day 6. Several research papers have even used single day dosage of 20mg with good results. Single doses as high as 60mg have been administered without negative results.
Letrozole has several advantages:
1. Letrozole has a very short half-life (~45 hours) and, therefore, is quickly cleared from the body. For this reason, it is less likely to adversely affect the endometrium and cervical mucus.
2. The results of several studies show that Letrozole and Letrozole + FSH cycles had the highest pregnancy rates.
There has been a lot of controversy that Letrozole use causes deformed babies, or that Indians have been made Guinea pigs for its trials. On the contrary, Letrozole is cleared faster from the blood than CC and therefore has lesser chances of affecting the conception, when it happens. CC in known to stay in the blood for upto six months after intake. Much before Letrozole came to India, hundreds of research papers were written all over the world and every paper only found benefits in its use. And lastly, before I rest my case, after all that media hype, Letrozole has been quietly given FDA approval by the government, for use in Fertility. Here is a link to a relevant artcile published in a reputed Journal, Fertility and Sterility in 2006: dx.doi.org/10.1016/j.fertnstert.2006.03.014
So, it is better you consult with a gynecologist and infertility specialist Dr. Rajeev Agarwal (director of Care IVF) before you are going under medications. It is better you understand the good and bad things of a controversial subject before you are going through a course.
There are number of infertility clinics. Study and check the infertility clinics in Kolkata before you enroll yourself for your IVF success.