Tuesday, May 27, 2008

Metformin

Metformin is an insulin-sensitizing agent. It is biguanide derivative developed in 1957 for diabetes cure and the primary activity of this medication is the suppression of hepatic gluconeogenesis.

Metformin is a highly popular antihyperglycemic drug for women with polycystic ovary syndrome (PCOS). It has proved its potential in the treatment of hirsutism (excess and unwanted hair growth disorder in women) and acne.

Insulin resistance and compensatory hyperinsulinemia are common conditions associated with women suffering from polycystic ovary syndrome (PCOS) and also act as a trigger to their hyperandrogenic state.

It is known that insulin boosts serum total and free testosterone by triggering ovarian androgen production and reduces serum SHBG concentration. Additionally, insulin is a key factor in hair production. At this backdrop, it has been concluded that medication (diazoxide, metformin and troglitazone) that improves insulin sensitivity in PCOS patients causes a reduction of hyperandrogenemia and hence is effective in the treatment of hirsutism.

Metformin acts on diabetic patients by hindering excess hepatic gluconeogensis and also improves peripheral insulin sensitivity. Metformin also helps in weight loss and control of blood pressure and LDL.

Effectiveness of metformin treatment

The effectiveness of metformin in the treatment of PCOS-related hirsutism is still being extensively researched. In one such research, Moghetti and his group administered metformin (1500 mg per day) for a range of 4 to 26 months in PCOS patients. They reported that women with excessive hair growth showed no improvement in the modified Ferriman and Gallwey hirsutism count (irrespective of any change in their menstrual process).

In another survey, the results of metformin use for hirsutism were investigated in PCOS patients whose condition remained unchanged after previous oral contraceptive pill (OCP) therapy. After this survey, it was noticed that after 6 months of metformin use (1500 mg/day) there was a moderate reduction in both F–G measures (10%) and hair growth rate.

Another more widespread survey of PCOS patients under OCP treatment versus metformin (1500 mg/day) treatment, encouragingly reported significant decrease in F–G count and average hair diameter in both cases. However, metformin was the better tolerated among the two treatments, with only three women stopping its use after gastrointestinal problems. On the other hand, seven women stopped their OCP usage due to resulting discomforts.

On the other hand the use of metformin in women with PCOS in a daily dose of 1000 mg for 3 months, followed by 2000 mg daily for another 3 months, showed that irrespective of a decrease in hyperinsulinemia, reduced serum androgens and improvement in menstrual cycles, there were no effects on the F–G scorecard.

In case of obese patients with PCOS, metformin use in eight surveys has proved to lessen circulating androgen concentration. This is achieved by increasing the amount of SHBG and hence reducing free serum androgen measures. However, in another four surveys there have been no improvements reported in either of these cases of metformin use.

Surveys have also been conducted to evaluate metformin effects on stimulation of ovulation in obese PCOS cases. The outcome has been highly encouraging, as both isolated metformin therapy and in combination with clomiphene citrate improved the degree of ovulation. Metformin is also often prescribed among pregnant cases and is a Category B drug.

Metformin and acne treatment

The use of insulin sensitizing agents like metformin to cure acne also requires more research. Many experts suggest that insulin sensitizers like metformin should help in acne treatment in the similar physiological process that also results in the effective treatment of hirsutism. In mild acne cases, use of metformin in daily amount of 1500 mg for a span of 12 months, there have been some improvements. However, changes in sebum secretion have not been noticed.

There have been suggestions that the advantages of antihyperglycemic treatment for acne cure could be dependent on the acuteness and type of the problem as well as the dose of the prescribed drugs.

Side effects of metformin

The adversities of metformin use include gastrointestinal discomforts such as nausea, diarrhea and abdominal bloating. These side effects can be countered with a low, starting dose and gradual increase spread over several weeks.

One very rare but serious side effect of metformin use is lactic acidosis. This can be avoided by a serum creatinine examination of patients before administration of this medication. Also, PCOS patients who are to be put on metformin or any other insulin sensitizing agents should be screened for liver enzymes before starting the therapy. This test must be again repeated after 6 and 12 months of use of the drug.

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