Hello everyone! Today I will conclude the entries on Letrazol and Clomid, emphasizing the warnings related to letrazole.
“Femara* (the trade name for letrozole) is contraindicated and should not be used in women who may become pregnant, during pregnancy and/or while breastfeeding, because there is a potential risk of harm to the mother and the fetus, including risk of fetal malformations.”
Who says so? Novartis, the company that makes the drug, put out this warning.
There are 2 elements to this statement. First and accurately, the drug has been shown to cause malformations in mice and rats when given in low doses during pregnancy. If is for this reason that we all believe that giving it to pregnant women is not indicated. Clomid also carries a warning that it is not to be used in pregnancy for fear of birth defects, although the potential for defects seems to be lower than for Femara. Nonetheless, Clomid carries a warning.
The second element has to do with taking the drug before pregnancy, as in the case of induction of ovulation. In 2006, the company issued a statement to physicians specifically stating that Femara is not indicated for use in the induction of ovulation.
How did this second statement from Novartis come ot be? In 2005 a very short abstract was presented at a scientific meeting showing the birth defect rate was higher in 150 women who took Femara as compared to the general population. That’s 150 births, not 150 birth defects. Now, no one wants to ignore important birth defect data, however 7 birth defects in 150 women is just too small a group to rely on. Based on this one preliminary study, Novartis quickly issued the warning to physicians.
Soon after the Novartis letter, another physician, Dr Tulandi, examined pregnancy outcome of 911 babies conceived after Clomid or letrozole treatment in infertile women. Here is the data directly quoted from the writings of Dr.Tulandi. “Overall, congenital malformations and chromosomal abnormalities were found in 14 of 514 newborns in the letrozole group (2.4%) and in 19 of 397 newborns in the CC group(4.8%). The major malformation rate in the letrozole group was 1.2% (6 of 514) and in the CC group was 3.0% (12 of 397). These differences did not reach statistical significance because of the relatively small sample size.”
Well then, it seems that clomid has a birth defect rate that is at leat equal to that of Femara, and yet Clomid is used much more and without and warnings. The point being that the early small study was not informative enough and Femara seems safe to use, at least as safe as Clomid. Now this second study was not perfect either, but it was bigger and better than the first.
These are not the only studies published on Femara. There have been dozens all showing that the drug can be very effective and none others have shown an increase in birth defects.
Why would the drug company want to sell Femara if there is controversy over its safety?
As we discussed previously, Femara is a medication that blocks estrogen production, which is very helpful for many women with breast cancer. Most women have the type of breast cancer that grows faster in the presence of estrogen. Blocking the body’s ability to produce estrogen using Femara can significantly slow the growth of the tumor. This is why the company produces the drug. Unfortunately, there is a tremendous market for such a product.
On the other hand, the fertility business is comparatively very small and it is associated with very large liability risks. Even if the data relating the drug to birth defects is poor, I can see why the company would want to protect itself from potentially crippling birth defect lawsuits.
The good news is that the drug is available and a licensed MD can prescribe any drug “off label”, as long as there is good evidence that the drug is helpful and there is no harm.
Tons of drugs are used off label. One fertility example is Lupron for endometriosis. This drug is mostly used to treat men with prostate cancer as it lowers testosterone levels which may help restrict tumor growth. Lupron is also used in women with endometriosis because it lowers estrogen levels, and endometriosis needs estrogen to grow. Many women take it and the literature is loaded with scientific articles supporting its use in medical studies. And yet, Lupron it not FDA approved for the treatment of endometriosis. (For those of you thinking ahead, yes Femara is used by some to treat endometriosis). Another example is the use of antiepileptic drugs to treat anxiety and depression. Believe me; the list goes on and on.
So where does this all take us?
1) Femara works for the induction of ovulation.
2) Femara should not be given during pregnancy.
3) Femara does not thin the lining of the uterus as may Clomid
4) Femara is relatively new and associated with more warnings.
It is the last statement that makes doctors understandably nervous about using it, especially when there is a close alternative (Clomid) that has been around since the 1960’s.
As time has gone by, I have used Femara more and more, but still use Clomid first. As more time passes and more studies are done, this may change, and it is possible that Femara may become the first line treatment over Clomid for all fertility doctors. Importantly, no one yet has proven that Femara leads to a higher pregnancy rate than Clomid.
Thanks for reading and don’t forget to read the disclaimer from 5.17.06.
Dr. Licciardi
Search Medpedia News & Analysis
Contributor
More from this contributor
- Fred’s Face Part 1
- The Answers to Infertility Quest...
- Clomid and Letrozole Part 2
- Dr. Licciardi Performing Surgery...
Comments
To add a comment to the original post, click here.
You must be signed in to post a comment.
Sign in nowAll blood work,tests, etc show me and my husband are totally fine. The Dr has suggested Letrozole and I'm concerned about using intervention considering that I have been able to get pregnant.
Will Letrozole actually increase my odds of carrying a baby? I'm guessing it's because we would know for sure when ovulation occurs and guarantee a long enough luteal phase but I'm not sure.
I would love more insight on this medication.
hcg buy online
Transport & Logistics Jobs | Careers & Recruitment at Jobscharger.com
http://www.jobscharger.com/JobIndustry/Transport-Logistics-38-.html
Thanks!
I've been using HOME CHECK OVULATION TEST KIT for a long time and I still get butterflies when that little smiley shows his face. :) I got one from the internet by searching on Google HOME CHECK OVULATION KIT it was great!
http://81-classic-collegiate-classes.com/
HeatherVonSJ[at]gmail[dot]com
IVF Mexico
I've been using HOME CHECK OVULATION TEST KIT for a long time and I still get butterflies when that little smiley shows his face. :) I got one from the internet by searching on Google HOME CHECK OVULATION KIT it was great!
Fertility Clinic Scotland,
I've been using OVULATION PREDICTOR for a long time and I still get butterflies when that little smiley shows his face. :) I got one from the internet by searching on Google HOME CHECK OVULATION TEST KIT it was great!
and here is the actual place to donate:
http://gogetfunding.com/project/desperate-for-a-baby!-surrogacy-in-california-is-my-only-option!
fertility doctor Mexico
My name is Michal Munk and I am pursuing a doctoral degree in clinical psychology at Fairleigh Dickinson University. As part of my dissertation I am researching the relationship between infertility, depression and body image in women, specifically as related to the differences between women with primary (unable to conceive and maintain a first pregnancy) and secondary (unable to conceive and maintain a pregnancy subsequent to having at least one child) infertility. I hope that findings from this study will eventually help develop better psychotherapy treatments for women with infertility.
Females between the ages of 18-50, who are currently infertile (have had unprotected sex for at least 12 months with no successful pregnancy), and have no adopted/step child(ren) are eligible to participate in this study. The study entails completing questionnaires either online (https://www.surveymonkey.com/s/YCBQ35D), or by hard-copy upon request (call: 347-766-3798), and may be completed in 20-30 minutes. Participation is voluntary and confidentiality will be maintained. For each person who completes the survey, 2$ will be donated to RESOLVE: The National Infertility Association. This study has been approved by the FDU IRB (2/17/12).
Feel free to contact me with any further questions about this study. I may be reached at 347-766-3798 or michalm@student.fdu.edu.
Thank you for your time and consideration.
Michal Munk, M.A.
Clinical Psychology
Fairleigh Dickinson University
I've been using OVULATION PREDICTOR for a long time and I still get butterflies when that little smiley shows his face. :) I got one from the internet by searching on Google HOME CHECK OVULATION TEST KIT it was great!
Fertility Clinic Scotland
Sperm Donors