What Devarin is and what it is used for. Devarin contains vardenafil, a member of a class of medicines called phosphodiesterase type 5 inhibitors. They are used for the treatment of .Whatever the cause is, due to muscle and blood vessel changes not enough blood stays in the penis to make it hard and keep it hard. Take special care with Vardenafil: If you have heart trouble. If your dose is different, do not change it unless your doctor tells you to do so. In case of hypersensitivity to tadalafil. Indications for use.Devarin tablets contain tadalafil at a concentration of 20 mg. It is a treatment for men who suffer from erectile dysfunction. Indications for use. It is used to treat erectile dysfunction . What Devarin is and what it is used for. Devarin contains vardenafil, a member of a class of medicines called phosphodiesterase type 5 inhibitors. They are used for the treatment of .  · Adults—10 milligrams (mg) as a single dose, no more than once per day, approximately 1 hour before sexual activity.Vardenafil will only work when you are sexually stimulated. This medicine should come with a patient information leaflet. Do not eat grapefruit or drink grapefruit juice while you are using this medicine. Different brands may not work the same way. How to Use: Always take this medicine exactly as your doctor has told you. Keep out of the reach of children. Check with your doctor or pharmacist if you are not sure.