Question 24. If I have PCOS, why do I need to take metformin? Isn’t that a drug for diabetics?

I must admit that I am just running on fumes today. I was in Boston yesterday so that I could visit Mom and try to raise her spirits a bit. It is tough to get old but as my Grandmother always said "it beats the alternative." Unfortunately, her poor health over these past few months has prevented her from going on the internet and I hate to ask my Dad to download these posts as he tends to get very frustrated at times with the download/print/share sequence. That means that there are now only 3 people reading this blog....

So what does any of this have to do with infertility or PCOS? Nothing. Hey, I told you I was running on fumes. But seriously, after abandoning my Special K diet yesterday in exchange for the Sunday Brunch at the Wollaston Golf Club....I feel like I have become diabetic. Now diabetes is a topic that does have something to do with today's Question of the Day so please read on....

24. If I have PCOS, why do I need to take metformin? Isn’t that a drug for diabetics?

The role of insulin resistance as the probable initiating factor in PCOS has important clinical implications. Because of the pioneering work done by Drs. John Nestler and Andrea Dunaif, the treatment of patients with PCOS has now shifted toward addressing the underlying issue of insulin resistance. Patients with PCOS are often treated with an insulin-sensitizing medication such as metformin (Glucophage). More than 20% of patients with PCOS and irregular cycles will experience a restoration of their normal cycles with metformin treatment. Because most patients who take metformin experience a diminished appetite, they may also benefit from weight loss with this therapy. Patients with PCOS also have increased rates of first-trimester miscarriage, and preliminary data suggest that there is a reduced rate of miscarriage in patients with PCOS who are treated with metformin.

In order to minimize the gastrointestinal side effects, the dose of metformin is increased gradually. Many physicians initially prescribe 500 mg a day of the extended-release preparation of metformin, to be taken at dinner. After 1 week, the dose is increased to 1000 mg; after another week, the dose is increased to the maximum of 1500 mg. Most patients can tolerate the medication, although severe gastrointestinal side effects (mainly diarrhea) arise in 10% to 15% of patients. Patients who fail to resume predictable cycles with metformin therapy alone will need to consider ovulation induction with fertility medications.

The use of metformin as a first-line medication in the treatment of ovulation problems in patients with PCOS is controversial. Some physicians believe that clomiphene should be the first medication prescribed to women with PCOS who desire pregnancy and have irregular cycles. Our preference has been to start with metformin and then add clomiphene if a women fails to resume regular menstrual cycles.

Kristin comments:
My OB suggested I try metformin to regulate my cycles. I started on 500 mg and eventually went up to 1000 mg—and it worked. I started to get regular periods. By charting my basal body temperature, I could tell that I was ovulating. I experienced major gastrointestinal issues with the drug, but they subsided after a month or so with some flare-ups on occasion. The side effects were worth it as far as I was concerned, especially if the metformin was going to help me get pregnant. When I started seeing an RE, my metformin dose was upped to 1500 mg. Once I did get pregnant through IVF, I remained on metformin for the first trimester of my pregnancy.