Always talk to your doctor about the risks and benefits of any treatment. Two of the questions from the IIEF served as primary study endpoints; categorical responses were elicited to questions about 1 the ability to achieve erections sufficient for sexual intercourse and 2 the maintenance of erections after penetration. Advise patients to seek prompt medical care in the event of a sudden loss of hearing or decrease while taking sildenafil. Its use is not studied in patients with severe hepatic impairment. The mean steady state volume of distribution Vss for sildenafil is L, indicating distribution into the tissues. Protein binding is independent of total drug concentrations.The four main medicines taken by mouth for erectile dysfunction are: Avanafil (Stendra). Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called . · VIAGRA is supplied as blue, film-coated, rounded-diamond-shaped tablets containing sildenafil citrate equivalent to 25 mg, 50 mg, or mg of sildenafil. Tablets are debossed with PFIZER on one side and VGR25, VGR50 or VGR on the other to indicate the dosage strengths. 4. Contraindications. 1 day ago · Hims is a telehealth company that provides both prescription and over-the-counter generic and brand-name medications. The brand focuses mainly on five medications, including Viagra, that have.