Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
shallow breathing, slow heart rate;
fast or pounding heart rate, muscle twitching;
confusion, unusual thoughts or behavior;
symptoms of stomach bleeding--bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;
problems with urination; or
easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin.
Serious side effects may be more likely in older adults and those who are ill or debilitated.
Common side effects include:
drowsiness, dizziness;
nausea, gas, upset stomach, stomach pain; or
sleep problems (insomnia).
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.
 Butalbital Compound side effects (more detail)
