Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Stop using Fioricet and call your doctor at once if you have any of these serious side effects:
fast, pounding, or uneven heartbeat;
feeling light-headed or short of breath;
nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes); or
easy bruising or bleeding, unusual weakness, fever, chills, body aches, flu symptoms.
Less serious Fioricet side effects may include:
drowsiness;
dizziness, confusion or lightheadedness;
dry mouth;
nausea, vomiting, stomach pain, loss of appetite;
feeling anxious or jittery;
drunk feeling; or
headache.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.