The generic name of Neurontin is gabapentin, and the drug is chemically unrelated to any other anticonvulsant or mood-regulating medication, and there is no generic form of Neurontin.

The drug was approved for sale in the U.S. in 1993 as a supplementary treatment for epileptic seizures.

Pfizer Inc., has pleaded guilty to illegally marketing Neurontin for unapproved illnesses.

Doctors can legally prescribe drugs for off-label purposes, but it's illegal for drug companies to market them that way. Medicaid spending on the epilepsy drug increased more than tenfold from 1996 to 2000.

Neurontin can result in suicidal tendencies, hostility and increased anxiety when used for 'off-label' illnesses. More Neurontin Side Effects >

Pfizer has paid over $430 million in penalties for illegally marketing Neurontin, and Medicaid fraud.

Approximately 90% of Neurontin usage is for off-label purposes.

Neurontin generated in excess of $1.3 billion in worldwide revenues in 2000, a substantial portion of which was derived from sales within the United States. Pfizer reported Neurontin sales of $432 million for the last quarter of 2000 and sales of $812 million for the first two quarters of 2001.

Pfizer is currently in litigation with multiple drug manufacturers to prevent the production of a generic drug form of Neurontin.