Phenacetin
Name: Phenacetin
Synonyms: 4'-Ethoxyacetanilide; 4-Acetophenetidine
Molecular Structure:
 Molecular Formula: C10H13NO2
Molecular Weight: 179.22
CAS Number: 62-44-2
EINECS: 200-533-0
Phenacetin, is an analgesic, but its use has declined owing to its association with several adverse side effects, some of which are described following. Typical doses are 300mg to 500mg a day. Phenacetin was introduced in 1887, and was used principally as an analgesic, and was one of the first synthetic fever reducers to go on the market. Phenacetin is also known historically to be the first analgesic without anti-inflammatory properties.
Its analgesic effects are due to its actions on the sensory tracts of the spinal cord. In addition, phenacetin has a depressant action on the heart, where it acts as a negative inotrope. Phenacetin is an antipyretic, acting on the brain to decrease the temperature set point. Phenacetin is also used to treat rheumatoid arthritis (subacute type) and intercostal neuralgia. Phenacetin was widely used until the third quarter of the twentieth century, often in the form of an "A.P.C." or aspirin-phenacetin-caffeine compound analgesic, as a remedy for fever and pain. However the U.S. Food and Drug Administration ordered the withdrawal of drugs containing Phenacetin in November 1983, owing to its carcinogenic and kidney-damaging properties. As a result some branded, previously phenacetin-based preparations continued to be sold, but with the phenacetin replaced by safer alternatives. A popular brand of phenacetin was Roche's Saridon, which was reformulated in 1983 to contain propyphenazone, paracetamol and caffeine. Coricidin was also reformulated without Phenacetin. Paracetamol is a metabolite of phenacetin with similar analgesic and antipyretic effects, but the new formulation has not been found to have phenacetin's carcinogenicity. Phenacetin is now being used as a cutting agent to adulterate cocaine in the UK, owing to the similar physical features of the two drugs. |