Metformin and PCOS

There is an adage in medicine that “like treats like.” So if you have a hormonal problem, then treat with hormones. If it is an anatomic problem, then treat with surgery…etc. In the case of PCOS, if this is an insulin related problem, then treat with a medication that addresses insulin issues. At Dominion, our preference has been for all patients with PCOS to take metformin. The majority of the patients tolerate the medicine and many resume normal cycles and conceive. For those patients in whom metformin alone is not sufficient, then we can induce ovulation with clomiphene or fertility injections (gonadotropins). Although an article in the New England Journal of Medicine suggested that starting with clomid is better, it is our opinion that starting with metformin first and then adding clomid if cycles fail to resume in 6 weeks makes the most sense.


So in continuing along in our PCOS theme, here is the “Question of the Day” from the book that patients at Dominion can get free of charge (with only a little bit of begging), but that the rest of the US will have to wait a few more weeks to get at Amazon.com.




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). Approximately 20% to 50% 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. The dose of metformin is increased gradually. Many physicians initially prescribe 500 mg a day of the extended-releasepreparation 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.