Oral medicine for ED also might not be safe or work well if you have: Very low blood pressure, called hypotension, or uncontrolled high blood pressure, called hypertension. Push the plunger of the syringe, then insert the tip into the bottle while holding the bottle upright on a flat surface. Place the tip of the syringe into you or your child’s mouth and point it towards the cheek. Keep out of the reach of children. Children 1 year of age and older weighing 20 kg or less—10 mg 3 times a day. These medicines all work well for ED. This medicine works best when you take it on an empty stomach an hour before sex. · For treatment of erectile dysfunction: For oral dosage form (tablets): Adults up to 65 years of age—50 milligrams (mg) as a single dose no more than once a day, 1 hour before sexual intercourse. Alternatively, the medicine may be taken 30 minutes to 4 hours before sexual intercourse. Your doctor may adjust your dose if needed. CHOOSE BRAND-NAME VIAGRA. The original little blue pill prescribed by doctors for over 20 years. Clinically proven to treat men with erectile dysfunction (ED) Ongoing commitment to product quality and safety monitoring. Generic Viagra (sildenafil) is an alternative to the branded Viagra drug that can be used for treating erectile dysfunction (ED). It’s now sold by many manufacturers, including online.