Acetaminophen is a generic pain reliever that is made to treat minor aches and pains. Generic Acetaminophen works as both an analgesic and antipyretic to treat aches, pains and reduce fevers. Acetaminophen is an over-the-counter favorite for millions of patrons worldwide based on its effective relief of common symptoms and the low risk of side-effects. Acetaminophen is most commonly known to treat headaches, but can also be used for muscle aches, colds, fevers, backaches, tooth aches and even arthritis.