Analgesics most commonly prescribed in dentistry for acute pain relief include the nonsteroidal anti-inflammatory drug, acetaminophen, and various opioid-containing analgesic combinations. The NSAIDs and presumably acetaminophen act by inhibiting cyclooxgenase enzymes responsible for the formation of prostaglandins that promote pain and inflammation. Opioids such as codeine, hydrocodone, and oxycodone stimulate endogenous opioid receptors to bring about analgesic and other effects. Numerous clinical studies have confirmed that moderate to severe pain of dental origin is best managed through the use of ibuprofen or another NSAID whose maximum analgesic effect is at least equal to that of standard doses of acetaminophen-opioid combinations. If an NSAID cannot be prescribed because of patient intolerance, analgesic preparations that combine effective doses of an orally active opioid with 600 to 1,000 mg of acetaminophen are preferred in the healthy adult. On occasion, prescribing both an NSAID and an acetaminophen-opioid combination may be helpful in patients not responding to a single product. In all cases, however, the primary analgesic should be taken on a fixed schedule, not on a "prn" (or as needed) basis, which only guarantees the patient will experience pain.