Researchers in the Netherlands investigated whether a common blood pressure drug could be used as a medication for Alzheimer’s disease.
Dementia describes a group of symptoms including memory loss, a decline in thinking processes, personality changes, and inappropriate behavior. There are several different types of dementia. Alzheimer’s disease is the most common cause of progressive (non-reversible) dementia in the elderly, estimated to be responsible for between 60 to 80 percent of all cases. It is marked by characteristic changes in the brain tissue, in particular, amyloid plaques and neurofibrillary tangles. The causes of Alzheimer’s disease are not clear but are thought to be a combination of genetic, lifestyle, and environmental factors.
Brain blood flow is reduced in early Alzheimer’s disease
Previous research has shown that blood flow to the brain is reduced in early Alzheimer’s disease, so drugs that improve brain blood flow might help to slow disease progression. Researchers in the Netherlands investigated whether a commonly-used blood pressure drug, nilvadipine, can improve brain blood flow in patients with mild to moderate Alzheimer’s disease. They recently reported their findings in Hypertension.
The researchers randomly assigned 44 patients with mild to moderate Alzheimer’s disease to receive either nilvadipine or a placebo once a day for six months. At the start of the study and at six months the researchers measured the patient’s brain blood flow using special magnetic resonance imaging (MRI) techniques. The MRIs showed that the blood flow to the hippocampus, the brain area involved in memory and learning, increased by 20% in the patients receiving nilvadipine compared to the placebo group. Blood flow to other brain areas was unchanged in both groups.
Nilvadipine improved blood flow in brain areas involved in memory and learning
These findings show that the decrease in brain blood flow in Alzheimer’s patients can be partly reversed in some important regions. However, the authors caution that it is not yet clear if this will lead to any clinical benefits for Alzheimer’s patients and further studies are needed.
The patients in this MRI study were part of a larger research project in 500 patients with mild to moderate Alzheimer’s disease investigating whether nilvadipine had any clinical benefits. Although overall, no benefit was observed, in a subgroup of patients with only mild dementia symptoms, there was a slower decline in memory.
“In future we need to find out whether the improvement in blood flow, especially in the hippocampus, can be used as a supportive treatment to slow down progression of Alzheimer’s disease, especially in earlier stages of disease,” said Dr. Jurgen Claassen, from Radboud University Medical Center, Nijmegen, the Netherlands, the study lead author.
Written by Julie McShane, MA MB BS
de Jong DLK, de Heus RAA, Rijpma A, et al. Effects of nilvadipine on cerebral blood flow in patients with Alzheimer Disease. Hypertension 2019; doi:10.1161/HYPERTENSIONAHA.119.12892.
American Heart Association, Press release: 17 June 2019. “Hypertension drug may hold promise for Alzheimer’s disease.” https://www.eurekalert.org/pub_releases/2019-06/aha-hdm061219.php