If you will be taking this medicine for pulmonary arterial hypertension, your doctor will want to check your progress at regular visits. We also looked at additional services, such as access to digital pharmacies and home delivery options. Keep from freezing. In many of the studies, of both fixed dose and titration designs, daily diaries were kept by patients. Sudden vision loss in one or both eyes can be a sign of a serious eye problem called non-arteritic anterior ischemic optic neuropathy NAION.Savings will vary by medication and by pharmacy. The discount plan organization is Hippo Network LLC, One World Trade Center, Suite New York, NY , . Rarely reported side effects include: an erection that will not go away (priapism). If you have an erection that lasts more than 4 hours, get medical help right away. If it is not treated right away, priapism can permanently damage your penis. sudden vision loss in one or both eyes. Generic Viagra (sildenafil) is available as a , , , and milligram (mg) pill and in liquid form. It’s meant to be taken as needed — about an hour before sex — but shouldn’t be.