Erectile dysfunction medications require a prescription from a licensed provider. However the dose is usually not more than 40 mg 3 times a day. This finding is consistent with the inhibition of PDE6, which is involved in phototransduction in the retina. There were highly statistically significant improvements on the two principal IIEF questions frequency of successful penetration during sexual activity and maintenance of erections after penetration on VIAGRA compared to placebo. Proper Use Use sildenafil exactly as directed by your doctor. An evaluation of visual function at doses up to twice the maximum recommended dose revealed no effects of VIAGRA on visual acuity, intraocular pressure, or pupillometry. Effects of VIAGRA on Vision: At single oral doses of mg and mg, transient dose-related impairment of color discrimination was detected using the Farnsworth-Munsell hue test, with peak effects near the time of peak plasma levels.Optum Store Sildenafil If you are experiencing the symptoms of erectile dysfunction (ED), you may have considered using Viagra or a similar ED medication as a possible treatment. But if you’ve. Getting a 3-month supply. You may be able to get a day supply of Viagra. If approved by your insurance company, getting a day supply of the drug could reduce your number of trips to the.  · VIAGRA is supplied as blue, film-coated, rounded-diamond-shaped tablets containing sildenafil citrate equivalent to 25 mg, 50 mg, or mg of sildenafil. Tablets are debossed with PFIZER on one side and VGR25, VGR50 or VGR on the other to indicate the dosage strengths. 4. Contraindications.