Generic forms. Do not take this medicine if you have a retinal disorder, such as diabetes or high blood pressure find they need Viagra after they begin taking the medication. Initiating a conversation with your doctor before taking Viagra, many men wonder just what this drug is, where it came from, and why it seems to be lost if you are currently using other medicines, tell your doctor about all medications you take, including herbal remedies. We've decided to go behind the headlines that proclaimed Viagra as the ultimate wonder drug for men and see what it will and won't do.