Can old drugs provide new hope in the fight against Alzheimer鈥檚 disease?
While most drugs developed to treat the disease have proven unsuccessful, research suggests some existing, tried-and-true medications used to treat high blood pressure may offer some protection for the brain against the ravages of dementia.
The drugs, called centrally acting ACE inhibitors and ARBs, are widely prescribed to lower blood pressure, but the medications are also able to penetrate into the brain.
Researchers around the world are finding that the patients who take these drugs are less likely to develop Alzheimer鈥檚 and dementia. One U.S study found a 65-per-cent lower risk of dementia among cardiac patients on these medications.
And researchers have just published a study on more than 400 Canadian senior citizens already diagnosed with mild to moderate dementia: Testing over 12 months showed that subjects who were taking these blood-pressure medications showed a slower rate of decline in daily-living activities. The patients were better able to care for themselves or take walks on their own, longer than those not on these drugs.
Lead study author Dr. William Molloy told 麻豆影视 that studying the potential of these drugs to treat dementia is critically important, given that so many Alzheimer鈥檚 treatments have failed.
鈥淏ecause we have nothing; we have absolutely nothing,鈥� Molloy said.
Molloy noted that 鈥渕illions of Canadians鈥� take the medications, and because they have been on the market for years, they are proven to be safe.
鈥淭here are no surprises with them,鈥� Molloy said. 鈥淰ery few side-effects, and they are generic and very cheap. So they have a lot of potential for us.鈥�
With more than 100 failed experimental drug treatments for Alzheimer鈥檚 in recent years, researchers, like Sunnybrook Health Sciences neurologist Sandra Black, say there may be new hope in old drugs.
鈥淲hat we are looking at here ... is called repurposing drugs: taking drugs we already know and that may have other effects than were intended,鈥� Black told 麻豆影视.
She speculates these ACE inhibitors or ARB medications do more than control blood pressure. They may work inside the brain to lower inflammation, or perhaps are stimulating neurotransmitters important for memory and attention.
With so much international interest in these drugs, Black has been given the green light for a new -- and likely world-first -- study, comparing two hypertensive medications: Perindopril (an ACE Inhibitor) and an ARB called Telmisartan. Both are generic drugs.
Black will test their effects on 250 Canadian patients with early Alzheimer鈥檚 over one year, measuring brain shrinkage, a common sign of degeneration. Patients will also be tested for changes in memory and quality of life.
If either or both medications appear to put the brakes on the brain disease, they could be readily prescribed to patients since they are already on the market.
鈥淚t鈥檚 going to be a study that has real implications for front-line care,鈥� Black predicts.
The study, which is expected to take two years, is being funded by the Alzheimer鈥檚 Drug Discovery Foundation and the W. Garfield Weston Foundation.
With a report from CTV鈥檚 medical specialist Avis Favaro and producer Elizabeth St. Philip
