It brings numerous — and more important — problems, as it impairs the cardiovascular function, the respiratory function and affects the psychology in a negative way. Some examples of nitrates are nitroglycerin Nitro-Dur, Nitrostat, others , isosorbide mononitrate Monoket and isosorbide dinitrate Bidil. It is a source of life. You can take it in a small dose daily or in a larger dose as needed. Severe liver disease. They enhance the effects of a chemical the body makes that relaxes muscles in the penis, called nitric oxide. An urologist provides the device, called Rigiscan, to the patient.What can I use instead of Viagra? As an alternative to Viagra, a person may wish to try any of the following: Alternative oral drugs: Including vardenafil, tadalafil, and avanafil. Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes . Generic Viagra (sildenafil) is an alternative to the branded Viagra drug that can be used for treating erectile dysfunction (ED). It’s Author: James Roland.