It is believed that the medications for controlling blood pressure could reduce the progression of more advanced Alzheimer’s. But a new study by the University of Bristol contradicts this belief suggesting that common blood pressure drug does not slow down Alzheimer’s progression.
This study determined whether the antihypertensive drug losartan and normal care would slow the progression of Alzheimer’s disease. Well, it found that the drug is ineffective in slowing down the progression of Alzheimer’s disease (AD) in people with the mild-to-moderate disease after 12 months of treatment. But, it suggests that it could be beneficial if prescribed for longer and given to people with very early diseases.
Scientists investigated whether the Losartan, a common blood pressure drug, could reduce brain volume loss compared to a placebo. This is the first study that evaluated the potential benefit of Losartan in clinically diagnosed AD.
Scientists used brain imaging as a primary outcome to check the results.
A total of 261 participants entered the open-label phase, of whom 211 were randomized to the intervention (n = 105) or placebo (n = 106) arms. From the 197 (93%) participants who completed the study, primary outcome data were available for 171 (81%).
The trial assessed the rate of whole-brain shrinkage (i.e., atrophy) on an MRI scan compared to participants on Losartan and placebo. The researchers also examined differences in memory tests, day-to-day quality of life, and in a subgroup of participants, changes in levels of vascular damage to the brain as measured by MRI.
Twelve months of treatment with Losartan was well tolerated but was not effective in reducing the rate of brain atrophy in individuals with clinically diagnosed mild-to-moderate Alzheimer’s disease.
Professor Pat Kehoe, Gestetner Professor of Translational Dementia Research at the University of Bristol, who led the trial, said: “With the current lack of effective treatments for Alzheimer’s disease (AD), this is an extremely disappointing result for participants, patients, and researchers alike that losartan, although well-tolerated, was not effective in reducing the rate of brain atrophy in people with clinically diagnosed AD in the 12 months it was given, especially after so much encouraging evidence to support the need for this trial.”
“However, we cannot exclude the possibility, given other findings that are emerging, that losartan, or similar drugs, given to people earlier and for longer in their development of Alzheimer’s, such as folk with certain types of mild cognitive impairment, might still be protective.”
“It is vitally important we continue to search for effective treatments for AD because, with an aging population, there will continue to be many people diagnosed with the disease, which will greatly impact on our already overstretched health and social care costs and resources.”
Scientists believe that further study is essential to assess the potential therapeutic benefit of earlier treatment in milder cognitive impairment or longer treatment periods.
- Prof Patrick Gavin Kehoe, Ph.D. et al. Safety and efficacy of Losartan for reducing brain atrophy in clinically diagnosed Alzheimer’s disease (the RADAR trial): a double-blind, randomized, placebo-controlled, phase 2 trial. DOI: 10.1016/S1474-4422(21)00263-5
- Patrick G Kehoe et al. Losartan to slow the progression of mild-to-moderate Alzheimer’s disease through angiotensin targeting: the RADAR RCT. DOI: 10.3310/eme08190