Fioricet medication is a pain reliever and sedative. It is used to relieve mild to moderate pain and tension headaches. Buy fioricet online from pharmacy To prevent upset stomach, take fioricet with food or milk. Pain medications work best in preventing pain before it occurs. Once the pain becomes intense, the medication is not as effective in relieving it. Take this as prescribed. Do not increase your dose or take it more frequently without your doctor’s approval. Fioricet may cause lightheadedness, dizziness, drowsiness, stomach upset, nausea, and sleeping disturbances the first few days as your body adjusts to the medication. …