You may take this medicine with or without food. To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and site usage information with other information we have about you. They include dutasteride Avodart, Jalyn and finasteride Propecia, Proscar. These include a heart attack, stroke or a serious heart rhythm disorder in the past six months. If you take too much Taking too much sildenafil can cause unpleasant side effects. Dosing The dose of this medicine will be different for different patients.Priapism warning: This drug can cause priapism, which is an erection that won’t go away. If you have an erection that lasts more than 4 hours, call or go to the nearest emergency room. If it. How much does sildenafil citrate or revatio cost near you? Find the best sildenafil citrate or revatio prices near you now with our cost comparison tool and start saving today. Sildenafil tablets for erectile dysfunction come in different strengths ranging from 25mg to mg. The usual dose is 50mg, when you need it. Do not take it more than once a day. The dose can be increased to mg or decreased to 25mg depending on its effect. Take sildenafil up to 4 hours before you want to have sex.