title: Can Viagra really cause hearing and vision loss?  If so, is this a reason to avoid using it?
mesh_terms: D002243:Carbolines / Q000009:adverse effects*; D034381:Hearing Loss / Q000139:chemically induced*; D006801:Humans; D007093:Imidazoles / Q000009:adverse effects*; D010726:Phosphodiesterase Inhibitors / Q000009:adverse effects*; D010879:Piperazines / Q000009:adverse effects*; D011687:Purines / Q000009:adverse effects; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000009:adverse effects*; D000068581:Tadalafil; D013997:Time Factors; D014227:Triazines / Q000009:adverse effects; D000069058:Vardenafil Dihydrochloride; D014786:Vision Disorders / Q000139:chemically induced*
chemical_list: D002243:Carbolines; D007093:Imidazoles; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014227:Triazines; D000069058:Vardenafil Dihydrochloride; D000068581:Tadalafil; D000068677:Sildenafil Citrate