Acetaminophen and NSAIDs relieve pain and also reduce fever. In addition to producing analgesia, NSAIDs also have an anti-inflammatory effect. Acetaminophen is classified separately from NSAIDs because it relieves pain by a different mechanism than do NSAIDs, and it has minimal anti-inflammatory properties. Acetaminophen is often the ingredient in "aspirin free" drugs, whereas NSAIDs are often referred to as "aspirin like" drugs. Although NSAIDs other than aspirin were originally developed to treat inflammatory conditions, such as arthritis, they are widely used to treat a number of both acute and chronic pain syndromes.

Acetaminophen and NSAIDs are used for acute and chronic pain caused by a variety of conditions, including surgery, trauma, arthritis, and cancer.

NSAIDs differ from opioid analgesics in the following ways:

• NSAIDs have an "analgesic ceiling" – an upper dose limit above which adverse effects continue to increase but there is no increase in pain relief.
• NSAIDs do not produce physical or psychological dependence.
• NSAIDs are antipyretic– they can lower fever.