The DCGI's approval to Mumbai-based Sun Pharmaceuticals to market letrozole for treating sub-fertility in young menstruating women in the country has raised eyebrows among the medical fraternity as its use in women of child bearing age is strictly prohibited elsewhere in the world due to severe side effects such as estrogen deprivation, ovarian atrophy, uterine atrophy, increased incidence of foetal malformations, foetal resorption and foetal death.

Letrozole, a product of Novartis, is indicated for use in cases of breast cancer in postmenopausal women all over the world.

According to sources, the DCGI has approved the drug on the basis of the phase III trials conducted by Sun Pharmaceuticals on a mere 55 patients, that too conducted by private practitioners in personal clinics. These studies should have been conducted on more number of patients by independent, experienced investigators in large, research hospitals attached to medical college to avoid any bias results.

All this is happening in India, while the Canadian drug regulator and the innovator company Novartis in individual letters to gynaecologists all over the world have warned them never to use letrozole for female infertility since research on 150 pregnancies has shown that babies born to mothers who had taken the drug suffered from bone malformations, heart defects and cancer.

Expressing concern over the DCGI decision, well-known health expert and Editor of the medical journal MIMS, Dr CM Gulhati said that letrozole has been granted approval in flagrant violation of Indian safety laws. "As per Drugs and Cosmetics Rules, even an old drug when used for a new indication is deemed to be a "New drug" and must undergo a series of safety and efficacy studies both in animals and humans before its use in general public is allowed", he said.

If the drug is intended for use in young women of child bearing age, reproductive studies including fertility studies, teratogenicity studies and pre natal studies must be performed in two female animals such as mouse, dog or rabbit.

The drug must also undergo phase I clinical trial in about 10 healthy volunteers (pre-menopausal women over 18 years of age) to determine the maximum tolerated dose and document preliminary side effects. Exploratory phase II studies to determine the therapeutic use, dose and safety of the drug are to be conducted in 10-12 patients in each of 3 to 4 research hospitals. Dr Gulhati regretted that none of the above studies were conducted by Novartis or any other company anywhere in the world since the drug was never intended to be used in women of childbearing age, Dr Gulhati said.

Meanwhile all efforts to contact DCGI Dr Surinder Singh did not materialize.

To an e-mail query in this regard, Sun Pharmaceuticals said, "We have conducted a trial as required, subsequent to which we have received marketing approval".