The main ingredients in Excedrin are acetaminophen, aspirin and caffeine, states Drugs.com. Both acetaminophen and aspirin relieve pain and fever, and aspirin also decreases inflammation. Caffeine stimulates the central nervous system and improves blood flow by relaxing the smooth muscle in blood vessels.
Excedrin is typically taken to relieve pain associated with tension headaches, migraine headaches, muscle aches, arthritis and menstrual cramps, notes Drugs.com. Excedrin is not recommended for children or teenagers with chicken pox, flu symptoms or fever, because the aspirin in Excedrin can lead to Reye's syndrome, which is a very serious and sometimes fatal condition that affects children. Patients with a history of liver problems, asthma, stomach ulcers, bleeding disorders or kidney disease should consult their doctor before taking Excedrin.
Common side effects of Excedrin include upset stomach, heartburn, depressed mood, anxiety and restlessness, states Drugs.com. Some patients may also experience difficulty sleeping while taking this medication. Serious side effects, including severe agitation or anxiety, unusual bruising or bleeding, lightheadedness, excessive thirst, or hot and dry skin, require an immediate call to a doctor. Other serious side effects include black or tarry stools, vomit that contains blood or looks like coffee grounds, slow or weak pulse, dark urine and yellowing of the skin or eyes.