How do painkillers like aspirin and acetaminophen relieve pain without making you numb?

November 10, 2008

How do painkillers like aspirin and acetaminophen relieve pain without making you numb?

Most of the commonly used painkillers (including aspirin, ibuprofen, and naproxen) are non-steroidal anti-inflammatory drugs (NSAIDs). They inhibit your body’s production of chemicals called prostaglandins that are involved in inflammation and sensitivity to pain. Thus, NSAIDs indirectly bring down inflammation and pain associated with it, by they don’t stop your nerves from feeling pain.

Acetaminophen (Tylenol) is a little bit different, and exactly how it works is still a matter of debate. It does not show anti-inflammatory effects. It is thought to inhibit production of prostaglandins, but centrally (at the level of the spinal cord).

This is in contrast with anesthetics like procaine (Novocaine), which cause numbness by keeping nerves from firing.

References:

Clinical Pharmacology [database online]. Tampa, FL: Gold Standard, Inc.; 2008. URL: http://www.clinicalpharmacology.com. Updated November 2008.

Permalink