If it is not treated right away, priapism can permanently damage your penis sudden vision loss in one or both eyes. Psychological factors like stress, depression, or anxiety can also contribute. Alpha-blockers are sometimes prescribed for prostate problems or high blood pressure. People with heart conditions should never take ED medications without consulting a doctor. Your primary care doctor should always know what medications you’re taking, including ED pills prescribed by another provider. Levitra vardenafil : This medication is taken one hour before sex and can last up to 24 hours.Dizziness, headache, flushing, or stomach upset may occur. Vision changes such as increased sensitivity to light, blurred vision, or trouble telling blue and green . And while generic Revatio is available only in a mg strength—Viagra comes in , , and mg tabs—not to worry: Your doctor can prescribe the most appropriate . They’re often the first line of treatment for trouble getting or keeping an erection, called erectile dysfunction (ED). Oral medicines for ED usually work well and cause few side .