Vioxx is another new drug in this class currently being marketed. Other drugs include phenacetin and butacetin, which act through an acetaminophen intermediate. These drugs are only weak prostaglandin synthesis inhibitors and have little anti-inflammatory action. Although useful as analgesics and antipyretics, they do not thin the blood like aspirin, nor do they affect uric acid disposition. Because of the lack of blood-thinning properties, acetaminophen is recommended for many hospital patients who may have open or healing wounds.
Hepatic toxicity can be a problem with acetaminophen, especially when alcohol is also present.
Cytochrome P-450 converts acetaminophen to acetamidoquinone. Glucosamine, a monomer, and chondroitin, a polymer, are being marketed as nutrients for this purpose. A new tactic is currently being exploited against rheumatoid arthritis, namely, inhibiting compounds manufactured in the liver that trigger production of catabolic enzymes in joints, causing degradation of cartilage. Ambrel is the first drug in this class to seek FDA approval.