They also demand a thorough investigation of the molecule, which is being used frequently in infertility clinics and found effective in many cases.
“The DCGI’s attitude is very disturbing. The patient would feel that the doctor does not know about drugs. We have to face the music,” Reeta Bilingady, clinical director of Sure fertility clinic in Bangalore told Deccan Herald.
DCGI removed the drug on the basis of a small-scale clinical trial involving 55 patients in three centres. But the minimum legal requirement for approving a new drug is a trial on 100 patients. Despite the DCGI acceding to the trial, the conditions were not completely fulfilled.
The drug’s original manufacturer, Novartis admitted in November 2005 that use of Letrozole led to “tripling of the risk of foetal abnormalities.”
That health regulators of Canada compelled Novartis to write individual letters to gynaecologists worldwide warning them of the dangers of Letrozole use in treating female infertility, over 500 of which were sent to Indian gynaecologists.
“There was no authentic trial on Indian population. The doses were fixed on the basis of a Canadian study and several Letrozole trials in breast cancer,” said Pune-based gynaecologist Bharati Dhorepatil who chairs the clinical research committee of the Federation of Obstetrics and Gynaecological Societies of India.
The Drugs and Cosmetic Rules require that while approving a drug for use in females of reproductive age, animal studies are to be done in this specific group. No such studies were done in India. The dose given to infertile women —- 5 tablets of 2.5 mg dose each for 5 days in a menstrual cycle — was not fixed through any proper trial on pre-menopausal women.
“The innovator did not conduct such studies because there was no plan to use Letrozole in pre-menopausal women. Thus marketing approval by DCGI was given in violation of rules,” C M Gulhati, a former World Health Organisation consultant on drugs, said, adding that even Novartis did not want to sell it in infertility treatment as the company knew the pitfalls.
Gulhati claimed that birth of one Indian baby with congenital defect was casually dismissed even though it supported the warning from Novartis.
After the DCGI approval, doctors abused it to a large extent. “Almost every gynaecologists prescribed Metronome without even checking whether a patient is indicated or not for this medicine. Its not an ideal drug for ovulation but doctors went crazy,” said Abha Mazumder, a former professor of All India Institute of Medical Sciences who is currently heading the In-Vitro Fertility Clinic of the Sir Gangaram Hospital in the capital.