Do not push the tablet through the foil. They are used for the treatment of erectile dysfunction in adult men, a condition which implies difficulties in getting or keeping an erection. Product Description Difarin 20 mg 4 tablets Devarin tablets contain tadalafil at a concentration of 20 mg. Follow your doctor’s orders or the directions on the label. Do not open the blister pack until you are ready to take the tablet. Children—Use is not recommended.Details The scientific name for Devarin is Vardenafil, which is a phosphodiesterase 5 enzyme inhibitor. This stimulates the effect of nitric oxide which relaxes smooth muscles, .  · Adults—10 milligrams (mg) as a single dose, no more than once per day, approximately 1 hour before sexual activity. Uses. Vardenafil is used to treat male sexual function problems (impotence or erectile dysfunction-ED). In combination with sexual stimulation, vardenafil works by increasing .