The Problem with Femara

Off Label Use

The drug known as Femara (letrozole) was designed to treat and prevent hormone-responsive breast cancer. But the drug also has admirers for its use as a fertility drug. The drug company Novartis, who holds the patent for the drug, has issued a warning against such off-label use, but doctors keep prescribing the drug for women who have had no success with Clomid.

Who Cares?

The company has a right to be concerned about liability for misuse of any drug it produces and markets, but women who have no avenues left to explore in their quest for a baby may not care overmuch. Clomid (clomiphene citrate) can help anovulatory women to ovulate, but 10% of women who try the drug find it doesn’t do the trick.

One of the earliest studies on the efficacy of Femara as a fertility treatment looked at 12 women who didn’t respond to Clomid. Nine of them ovulated and three of them conceived when put on Femara. The researchers then compared the effects of both drugs using a group of 19 women. Ten of them were given Clomid and the other nine were dosed with Femara.

Scientists saw no significant difference in the rates of ovulation, the thickness of the uterine lining, or the number of eggs produced as a result of either therapy. A later study was suggestive of the fact that Clomid does thin the uterine lining, but that Femara does not. Femara comes with a lowered risk for miscarriage, too.

Doctors are still experimenting with the optimal dose of Femara for its use as a fertility drug. While tests have been performed with doses of 2.5 mg, 5 mg, and 7.5 mg, there is no conclusion over which dose is best. Doctors do find that the optimal treatment time is five days.

While both Clomid and Femara have similar conception rates, expensive Pergonal and other like gonadotropin drugs are still the winners in the conception game. And of course, older women have lower rates of conception than younger women, but that’s to be expected.

Femara begins to leave the body as soon as the last dose is taken, and the duration of treatment is short, so that side effects are very minimal. However, when used as a five year treatment as a breast cancer drug, the side effects can be much more severe than a short, five day course for fertility treatment.