How often does sildenafil need to be taken to reduce the risk of Alzheimer’s disease? Elizabeth Tracey reports


Men who took sildenafil for erectile dysfunction experienced less Alzheimer’s disease than men who did not, a very large study looking at medical records found. One problem, says Lolita Nidadavolu, a Johns Hopkins geriatrics expert and coauthor of an editorial on the study, is it’s not possible to determine exactly what dose of the medicine was used.

Nidadavolu: So they did find in the study that those that had over 20 refills, what that means in terms of the actual dose that someone has been taking, someone may not necessarily take all those tablets that they're prescribed and they may not take it continuously for example, so it is hard to say that there is strong dose effect but there really was a trend and this observational study where those that had those higher numbers of refills seemed to have a lower incidence of developing dementia.    :29

Nidadavolu says this points to the need for a large clinical trial where such questions would be answered. At Johns Hopkins, I’m Elizabeth Tracey.