Sorry something went wrong with your subscription Please, try again in a couple of minutes Retry. How should this medicine be used? Do not mix the liquid with other medications or add anything to flavor the medication. Place the tip of the syringe into you or your child’s mouth and point it towards the cheek. Click here for an email preview. What should I do if I forget a dose? However, if you take sildenafil with a high-fat meal, it will take longer for the medication to start to work. · Sildenafil is used to treat men who have erectile dysfunction (also called sexual impotence). Sildenafil belongs to a group of medicines called phosphodiesterase Missing: jelly. Sildenafil is in a class of medications called phosphodiesterase (PDE) inhibitors. Sildenafil treats erectile dysfunction by increasing blood flow to the penis during sexual stimulation. Missing: jelly.  · For oral dosage forms (suspension or tablets): Adults—20 milligrams (mg) 3 times a day. Your doctor may adjust your dose as needed and tolerated. However, the .