The US Food and Drug Administration (FDA) has approved CombinatoRx’s New Drug Application for the painkiller tablet Exalgo for use by opioid-tolerant patients.

The hydromorphone HCl extended release tablet is intended to manage moderate to severe pain in opioid-tolerant patients who require continuous, round-the-clock opioid analgesia for an extended period of time.

The FDA approval allows CombinatoRx to receive $40m from Covidien, which will market the product in the US, as well as royalty payments on sales of Exalgo.

Covidien is also responsible for all post-approval FDA regulatory filings and owns the intellectual property for the drug.

Covidien is expected to launch the drug in the first half of 2010.