Sildenafil is the generic term for Viagra and many companies now make this product. Use the 25mg tablet if possible rather than the 50mg or 100mg. None of them are good for you, if you have a weak heart or higher blood pressure.
Much less damaging is a medicine which will strike fear into the heart of most of the men reading this. It’s called Caverject and is injected direct into the old fella. The reason it’s less damaging is because it only acts on your old chap, unlike Viagra/Sildenafil, which affects your whole body, enlarging every blood vessel you’ve got. Get your courage up and talk to your doctor.