Purdue Pharma announced this week that an abuse-resistant form of its controversial pain reliever OxyContin would not be available next year as planned. The announcement was a major disappointment for the drug manufacturer, which has been taking criticism from health officials and activists who want the drug banned. OxyContin, which produces a heroin-like sensation when crushed and snorted or injected, has been linked to dozens of overdose deaths.

Purdue had planned to develop a drug similar to OxyContin with a narcotic antagonist to prevent its opiate effect if the pill was used improperly. During clinical trials, though, researchers discovered that the antagonist, the narcotic blocker naloxone, blocked pain relief as well. Purdue Pharma officials admitted that complete testing may take several more years to complete.