According to a new enzyme which is discovered, may interpret the reasons for acetaminophen acting differently from other painkillers. Acetaminophen (paracetamol in the UK) is known to relieve pain and fever, but not inflammation. Whereas aspirin and ibuprofen tackle inflammation too and are known as non-steroidal anti-inflammatory agents (NSAIDs). These drugs are known to block two enzymes - cyclo-oxygenase (COX)-1 and COX-2. It is COX-2 which generates pain signals, but COX-1 helps produce the protective mucus that lines the stomach. Inhibition of COX-1 leads to the sometimes serious side effects of NSAIDs like stomach irritation and bleeding.
Researchers at Brigham University in the US have now discovered a new COX enzyme, COX-3, which appears to be the target of acetaminophen. This explains why the drug is a good painkiller, even though it has very little effect on COX-1 or COX-2. The study may help scientists discover even more useful painkillers in the future. Acetaminophen is useful for people who can't take standard NSAIDs and is, in general, very safe.