Erectile dysfunction is a very common disease amongst older men, and the commonest reasons for it are disroders of blood flow to the penis, disorders of nerve supply, or underlying psychological reasons such as depression etc.
With the advent of Viagra and its competitors Levitra and Cialis, first-line treatment of ED nowadays takes the form of the abovementioned pills. Each individual is different, so what works for one patient may not have such a good effect for another.
I would suggest discussing your responses with your prescribing urologist, to make sure that you are taking the medication correctly. If you are, you can then try either Cialis or Levitra as alternative options. If all 3 don't seem to acheive the desired response for you, your urologist can then offer a further evaluation of your ED problem with sophisticated imaging techniques, as well as an Endocrine workup.
Dr Ash Tewari, MD