But several leading AD researchers have expressed serious doubts about the drug‘s effectiveness and safety at the higher 23 mg dose. And Public Citizen, a medical watchdog organization, has filed a petition with the FDA to request that the drug marketed as Aricept 23 be withdrawn immediately.
“Aricept went off patent last year, so in order to maintain a proprietary drug they came up with a dose formulation that you couldn‘t easily duplicate by taking two [standard dose] 10 mg pills,” said David S. Knopman, MD, professor of neurology at Mayo Clinic in Rochester, MN. “If the higher dose were more effective, I would have no objection, but the clinical trial conducted by Aricept‘s sponsors failed to meet basic standards for demonstration of efficacy. I would like to see the scientific leadership of the neurologic community go on record as objecting to this misleading interpretation of the clinical trial data.”
Donepezil, manufactured by the Japanese drug company Eisai in partnership with Pfizer, was recording sales of about $2 billion a year before the expiration of the patent opened the way for less expensive generic versions of the drug. Eisai predicted generic competition would cut sales by 60 percent within three years.