The COX-3 inhibitors acetaminophen and metamizole are both analgesic and antipyretic drugs with weak anti-inflammatory properties. They primarily work in the CNS through both prostaglandin dependent and independent pathways. These drugs appear to be relatively safer than NSAIDs as they are only weak inhibitors of the peripheral cyclooxygenases. Acetaminophen is associated with liver toxicity, but this only occurs in doses higher than the daily recommended dose, and in patients with a weakened liver function. Metamizole is known to be associated with agranulocytosis, but it was proven that the estimated incidences were greatly exaggerated and that metamizole is relatively safe compared to other well-known analgesics.