When first starting this medication, people will often experience upset stomach or diarrhea which usually resolves after the first week. This side effect can be minimized by taking metformin with a meal and starting with a low dose. I recommend that our patients start with one 500 mg pill daily the first week and increase to twice a day during the second week. If after the second week GI side effects are minimal, the dose is increased to 850 mg twice daily. Patients with reduced renal function (creatinine >1.5 or creatinine clearance <60%) are at a higher risk for a rare side effect of metformin therapy called lactic acidosis, and the drug should be given cautiously, if at all, to such patients. Patients taking metformin should notify their physician and discontinue the medication:
Laparoscopic ovarian drilling may be considered for those women where other indications for laparoscopy are present.
While safety during pregnancy has not yet been established, there are no reports of abnormal babies in women who conceived using metformin and all resulting babies were normal. Metformin is a category B medication. This means that insufficient human data is available but no credible animal data suggesting a teratogenic (could produce birth defects) risk. Although to the best of our present knowledge the risk of birth defects would be small, it must also be noted that maternal diabetes has been associated with an increased risk of birth defects and the underlying elevated insulin levels may lead to birth defects if not corrected.
While the most prudent policy may be to avoid the use of these medications during pregnancy until more data on pregnancy outcome is available, the risk of miscarriage may be reduced by continuing metformin during the pregnancy. We ask our PCOS patients taking insulin-lowering medications to monitor their menstrual cycles – if pregnancy is suspected, do a B-HcG to confirm. Rather stop the Metformin when pregnancy test is positive.