It is estimated a growing use of PDE-5i drugs in Brazil, which trade moves annually more than 70 million dollars with high investment by the pharmaceutical industry.
The use of PDE-5i drugs has been associated with several adverse effects.
Other studies have focused exclusively on the use of PDE-5i in young adults (17,18), without exploring other medications used for enhancing erection.
Among those who reported using EDD during the last year, 38% used sildenafil, 14% non-regulated PDE-5i, 12% other medications such as tonics and vitamins, 10% tadalafil, 6% vardenafil and 6% lodenafil.
Non-regulated PDE-5i were the second most used EED which may reflect their lower cost and ease of purchase without prescription, as well the lack of control of illegal trade of these products.
A high proportion of men use non-regulated PDE-5i and non-evidence-based EDD.
Study author Gerald McGwin, a professor of epidemiology in the UAB School of Public Health, said: "It appears from these findings that the current government warning regarding hearing loss and the use of PDE-5i medications is warranted.
n 2007, following the report of several case studies potentially linking PDE-5i use and sudden hearing loss, the Food and Drug Administration announced labeling changes for PDE-5i medications so that the risk of hearing problems was more prominently displayed.
Men who reported use of PDE-5i medications were twice as likely to also report hearing loss as were men who had not used the drugs.
PDE-5i drugs were originally designed to treat pulmonary hypertension and are now used extensively in the treatment of erectile dysfunction (ED).
McGwin acknowledged limitations in the study, including the limited sample size for tadalafil and vardenafil, concerns over under-reporting of use of PDE-5i medications and confounding factors such as pre-existing conditions that might also contribute to hearing loss.