A new drug to treat patients in the early stages of Alzheimer's disease has been added to the arsenal of treatments for the degenerative brain disease.
Some of the most extensive testing ever done on people suffering from mild to moderate Alzheimer's disease found that the drug, called rivastigmine, improved or stabilized general brain function, behavior and cognition. The drug has been tested on more than 5,300 patients worldwide.
The Food and Drug Administration approved the drug for U.S. sale on Friday.
Sold in capsule form as Exelon by Novartis Pharmaceuticals Corp., the drug appears to offer similar benefits but somewhat less dangerous side effects compared to the other products that attack the same chemical targets. None of the drugs cure the disease.
''A new therapy such as Exelon, which can affect symptoms early in the disease and is proven effective in all critical domains of the illness, provides new hope for Alzheimer's patients and their caregivers,'' said Dr. George Grossberg, director of the division of Geriatric Psychiatry at St. Louis University School of Medicine.
During the trials, patients treated with 6 milligrams to 12 milligrams a day of Exelon were more likely to experience substantial cognitive improvement and less likely to show substantial decline than were patients given placebo.
At the end of the trial period, 81 percent of those on the drug had greater improvement of cognitive function than did the average placebo-treated patient. The treated patients also showed significant improvement over the control group in areas such as word recall and recognition, orientation and ability to speak.
Exelon was specifically developed to have less toxic effect on the liver than similar drugs already used to treat Alzheimer's patients. But while it left their livers alone, the drug caused nausea and vomiting among many of the patients taking it. In the trials, 26 percent of the women and 18 percent of the men who took high doses lost at least 7 percent of their initial body weight due to stomach upset.
Some patients have been taking the drug for more than three years, and some - at least to their caregivers - seem to have remained basically stable.
Like the existing drugs, tacrine (Cognex) and donepezil (Aricept), Exelon works by inhibiting enzymes called cholinesterase, which attacks a vital signaling chemical in the brains of Alzheimer's patients. By blocking the attacks, more of the neurotransmitter is preserved for normal memory-related and cognitive functioning.
''Each of the approved drugs for Alzheimer's disease may have different side effects on individual people taking the medication,'' said Bill Thies, vice president for medical and scientific affairs at the Alzheimer's Association, a national voluntary health organization dedicated to curing the disease.
''Having more approved drugs offers doctors, people with the disease and their families a greater opportunity to find one that will have some benefit with the fewest unwanted side effects,'' he added.
But since each patient responds differently to the three drugs, it's important to weigh the benefits, risks and costs of each, Thies said.
Novartis says the drug will be available in pharmacies by the end of May, with a wholesale price of $130 for a month's supply.
Four million Americans suffer from Alzheimer's disease, which afflicts mainly the elderly, gradually stealing their memories and ability to care for themselves, and eventually killing them.
The Alzheimer's Association projects that unless a way to prevent or cure the disease is found, some 14 million Americans will be victims of the disease in 50 years.
(Contact Lee Bowman at BowmanL(at)shns.com or http://www.shns.com.)