Purdue Pharma has been asked to suspend sales of its Palladone (hydromorphone) painkiller by the US Food and Drug Administration because of dangers related to using the drug with alcohol.

The drug, a potent opioid analgesic, was approved in September by the FDA for the management of persistent, moderate-to-severe pain in patients requiring continuous, around-the-clock analgesia, and launched in the USA in February. But the agency is now concerned that alcohol interferes with the drug delivery system used in the once daily product, causing “dumping” of the active ingredient. This could lead to higher than recommended blood levels of the painkiller, raising the risk of breathing difficulties, coma and even death, according to the FDA. Purdue has agreed to withdraw the product.

This is another heavy blow for Purdue, which last month lost a legal appeal to halt sales of a generic version of its top-selling product, the painkiller OxyContin (oxycodone). Faced with rapid erosion of its OxyContin revenues, Purdue promptly announced plans to cut more than 800 jobs. According to IMS data, US sales for OxyContin were approximately $2 billion dollars for the 12 months ended March 31, 2005. Meanwhile, Purdue is also being investigated over its marketing tactics for the product.

While Palladone was not expected to reach the sales volumes achieved by OxyContin, the loss of a product in its growth phase will make it harder for Purdue to weather the loss of its OxyContin exclusivity. The FDA said in a statement that Pallodone had so far been used “in a relatively small number of patients”, but added: “We are concerned that as more patients take this drug, safety problems will arise since even having one alcoholic drink could have fatal implications.”

Purdue said it intends to carry out reformulation studies and try to return Pallodone to the market in a new version. It said it was unaware of any case in which concomitant use of the drug and alcohol had caused injury in the 11,500 patients who have used the product to date.