Irish pharmaceutical firm Elan has agreed to pay a fine of $203m for illegally promoting its epilepsy drug, Zonegran.

Japan-based drug manufacturer Eisai, which purchased the drug from Elan, has also agreed to pay an $11m fine for off-label marketing of the drug.

Elan will plead guilty to a misdemeanour for promoting the drug for a number of uses that the company failed to seek approval for, including mood stabilisation and eating disorders.

The $203m breaks down as a $97m criminal fine, $102.3m to resolve civil allegations and forfeiting $3.6m in assets.