What Is Entacapone?

Entacapone is the international nonproprietary name for Comtan, a prescription drug used to treat Parkinson's disease. This is defined as a degenerative disorder of the central nervous system (CNS) commonly associated with a decline of motor skills that include slowed movement and uncontrollable shaking. Finnish pharmaceutical company Orion Corporation develops the drug. Another pharmaceutical company, Switzerland-based Novartis International AG, markets it under the Comtan brand name.

The Comtan term—also rendered as COMTan—comes from entacapone's function as a catechol-O-methyl transferase (COMT) inhibitor. This means that it prevents the enzyme catechol-O-methyltransferase from degrading neurotransmitters such as dopamine, epinephrine and norepinephrine. These substances are sometimes referred to as catecholamines, hormones of the sympathetic nervous system (SNS) that contribute to the regulation of response to stress. Dopamine in particular is essential, since Parkinson's disease is linked with the death of dopamine-containing cells.

According to some researchers, however, to be effective at all, entacapone must be combined with carbidopa/levodopa, a combination of drugs usually marketed under the brand name Sinemet. Orion and Novaris manufacture and market the drug, respectively, as Stalevo. This combination is meant to treat the end-of-dose "wearing-off" signs of Parkinson's disease, with entacapone aiding the carbidopa/levodopa in reaching the brain to increase effectiveness.

Entacapone is manufactured as a 200-milligram tablet and is meant for oral administration. The medication should be taken up to eight times daily, and can be ingested with or without food or drink. People who plan on taking entacapone should tell their doctors if they are allergic to certain drugs, have or have had liver disease or battled alcoholism, plan to have surgery, or have plans for pregnancy.

It is important to note that entacapone is used to control the signs of Parkinson's disease, not cure it. Moreover, the drug may cause side effects such as diarrhea, dizziness, drowsiness and gastrointestinal problems such as abdominal pain and diarrhea. More serious side effects include breathing difficulties, confused moods, hallucinations, high fever, muscle stiffness and weakness. Entacapone can also cause urine to turn into a brownish-orange color, although this is not deemed a harmful sign.

As of April 2011, Entacapone is an unscheduled drug according to the United States Food and Drug Administration (FDA) and the Drug Enforcement Administration (DEA). This means that it does not fall into any of the pharmaceutical classifications established by the Controlled Substances Act, the U.S. drug policy enacted as part of the Comprehensive Drug Abuse Prevention and Control Act. Although it was approved in 2003, the FDA began reviewing entacapone in 2010 as a drug that may increase the risk for developing prostate cancer or cardiovascular ailments.