You can take it up to 4 hours before you want to have sex. These medicines are generally recognised as safe and tend to be available in smaller package sizes only. 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. They are dispensed by a pharmacist. The changes from baseline in scoring on the two end point questions frequency of successful penetration during sexual activity and maintenance of erections after penetration were highly statistically significantly in favor of VIAGRA. The three classes of over-the-counter drugs are: May only be sold by a pharmacy Some over-the-counter drugs UA class may only be sold by a pharmacy, where staff can explain how they can be used safely and correctly. 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.Viagra (sildenafil) is a prescription drug that’s used to treat erectile dysfunction (ED). The drug comes as a tablet you’ll take by swallowing. It’s usually taken as needed about 1 hour. Examples of Viagra’s more commonly reported side effects include: headache. flushing (temporary warmth, redness, or deepening of skin color) stuffy nose. indigestion (upset stomach) mild vision. reviews. helpful votes. Re: viagra. 12 years ago. ArchAngel – love that one! lol; Simon, this question is often asked on test1.ru have a look there and there are .