Alzheimer’s: Study links Viagra to reduction in cases – 02/16/2024 – Equilíbrio

Substances used to treat erectile dysfunction, such as Viagra (sildenafil) may be associated with a reduction in cases of Alzheimer’s in old age. A new study published this month in the scientific journal Neurology followed more than 260,000 men and observed a relationship between the use of more than 20 prescriptions and a lower chance of developing dementia.

Although the new results are robust, Rui Daniel Prediger, researcher and professor at UFSC (Federal University of Santa Catarina) says that caution is needed. The expert states that there are more than 20 substances that show the same relationship, but in recent decades only one new type of medication, anti-amyloids, have been approved for treating the disease. “There is a discrepancy between epidemiological studies and the substance’s ability to treat the disease”, he highlights.

Sildenafil belongs to the class of phosphodiesterase type 5 (PDE5) inhibitors, an enzyme that acts to control erections. In addition to erectile dysfunction, the compound is also capable of relaxing the artery walls and can be used to treat pulmonary arterial pressure, being present in the composition of Revatil. There are other PDE5 inhibitors with similar effects, such as tadalafil (Cialis) and vardenafil (Levitra).

The relationship between the use of these inhibitors and the protection of the brain against dementia is still unclear. Some preliminary research has shown that these substances can promote the increase of an intermediate compound, a nucleotide called cyclic guanosine monophosphate (cGMP), capable of benefiting memory. Studies in mice have confirmed these effects, but it is not yet known whether the same mechanism occurs in humans.

Until now, the scientific evidence has been contradictory. But the new study, which involved more than 200,000 participants, brings more robust results than previous ones and reveals that there is a correlation between drugs such as sildenafil and neuroprotection against Alzheimer’s. To carry out this research, data from a British cohort collected between 2000 and 2017 were used.

To measure the use of drugs for erectile dysfunction, scientists used the number of prescriptions received by patients — after 2018, sildenafil began to be sold over the counter in England — and clinical diagnoses of Alzheimer’s. For every 10,000 participants, the results show that per year, 8 people undergoing treatment for erectile dysfunction were diagnosed with Alzheimer’s versus 10 who were not prescribed PDE5 inhibitors.

Grouping the men who took sildenafil by the number of prescriptions received, however, the researchers saw that there was only a reduction in Alzheimer’s cases among those who obtained more than 20 prescriptions within a 5-year interval. Numbers smaller than this did not lead to a reduction in Alzheimer’s cases.

The research work, however, has several limitations. Firstly, it was based on prescriptions issued by doctors, but it did not confirm whether the patients actually underwent the treatment. Second, Alzheimer’s diagnoses were made in primary care, without the aid of laboratory analysis, and do not reflect the real number of cases. Despite this, the researchers took into account the margin of error and state, in the work, that the clinical detection of the disease is highly accurate.

To determine the effectiveness of the drug, those responsible for the research emphasize that clinical studies are still needed, with pre-defined doses, randomized trials and the use of placebo. They also highlight that it is necessary to identify the best stage of the disease to start treatment and the effects on women must be studied.

Other research corroborates the results of American scientists. At the end of last year, a study published in Plos One analyzed the medical records of patients over 65 years of age and with conditions that allow the use of PDE5 inhibitors in the USA, that is, erectile dysfunction, benign prostatic hyperplasia and pulmonary hypertension. The methodology used, therefore, allowed the inclusion of a small number of women in the investigation.

After collecting the data, the researchers compared participants with Alzheimer’s and related dementias with control groups and saw a reduction in cases among those who were possibly treated with sildenafil or tadalafil. However, like the previous study, the research also has limitations that need to be overcome in the future. Among them, the lack of randomization of patients who received the medication or not. To achieve this, scientists recommend carrying out phase 3 clinical studies.

Another scientific article published in the magazine Alzheimer’s & Dementia surveys the research work completed on these drugs and also concludes that PDE5 inhibitors deserve additional studies to prove their effectiveness in preventing Alzheimer’s. According to the authors, there is sufficient evidence to support this hypothesis, but there is still a lack of research on human beings to justify this type of medical prescription.

Einstein Camargo, geriatrician and researcher at UnB, reminds us that there are safer and more reliable measures that can guarantee healthy aging. Like other dementias, Alzheimer’s is a multifactorial disease that is influenced by genetic components, but the first symptoms can be delayed with simple measures, such as improving educational level, intellectual stimulation, combating stress, having a good social life and improving sleep. .