This leads him to develop an addiction to the narcotic painkiller Dilaudid. Currently sufentanil is the most potent opioid painkiller available for use in humans. In the hospital, he became addicted to Pabinal, a morphine-based painkiller. He also frequently takes Vicodin, a moderate to severe painkiller, to relieve his pain. Bennett died later that month of an apparent accidental overdose of the painkiller fentanyl. Blood tests were positive for cannabis, cocaine and the painkiller Tramadol. In November 2000, Griffith returned to drug rehabilitation for treatment of a painkiller addiction. Bunting was addicted to the painkiller Percocet from 2006 to 2011. Jackson said during the 1993 interview that he began taking painkiller medications regularly in 1984. Toxicological tests showed potentially lethal levels of the painkiller Darvon in her system. Furthermore, his management team only became aware of his painkiller addiction in November 2014. He described it as a potent painkiller, but recommended that it be used sparingly. Scientists use this poison to make a painkiller. In its aftermath, Lewis became addicted to the painkiller Percodan for thirteen years. It is reputedly the birthplace of the popular drink known as the Painkiller.