Women with polycystic ovary syndrome (PCOS) often undergo protracted treatment with metformin and are disinclined to stop: indications for a change in licensing arrangements?

Women with polycystic ovary syndrome (PCOS) are increasingly being treated with metformin as an insulin sensitizing agent to reduce symptoms of hyperandrogenism and promote fertility. Indications such as hirsutism and cycle regulation require long term treatment. The drug is also being used through pregnancy. It is not licensed for any indication specific to PCOS, which means that much of this prescribing is taking place in an environment short of reliable information concerning safety. We describe the failure of recruitment to a study undertaken to explore the effects of metformin treatment discontinuation in women with PCOS, to provide both clinical and aetiological information. The study failed because the patients did not wish to stop treatment, and it illustrates the problems facing doctors working in this area. To achieve a safer prescribing environment, we recommend that action be taken by the manufacturer of metformin to work with regulatory agencies on a European base to extend prescribing indications for metformin to women with PCOS.