Sdf 20 pill it is taken by mouth with a glass of water approximately 0,5-1 hour before sexual activity. Fildena should not be taken more than once a day. A serious allergic reaction to this drug is very rare, but seek immediate medical help if it occurs. Store your medicines at room temperature between 68-77 degrees F (20-25 degrees C) away from light and moisture. Do not store the drugs in the bathroom. Keep all drugs away from reach of children and pets.