What is the drug orbivan used for and what are the possible side effects?

Orbivan: Orbivan combines acetominophen (tylenol), butalbital (a short to intermediate-acting barbiturate), and caffeine. It can be used intermittently for tension headaches, but can be sedating and habit-forming because of the butalbital. Because it contains 300 mg of acetominophen, it can build up and cause liver toxicity. It can cause dry mouth, dizziness & fatigue, but in some produces agitation.