The caffeine portion of the medication inhibits phosphodiesterase.
Caffeine is thought to enhance the analgesic effects of acetaminophen.
The active ingredients peak at varying time intervals but averages between 1-3 hours with effectiveness persisting for 34 hours. Children and teenagers who have chicken pox or flu symptoms. Persons who drink 3 or more alcoholic drinks daily. Pregnant and nursing mothers. Persons who take anticoagulation therapy.