Addiction experts are concerned after hearing reports that a stronger, more powerful painkiller could be headed to prescription markets.Patients who suffer from chronic pain or have surgery are often prescribed hydrocodone buffered with acetaminophen to ease their misery.But officials from four drug companies said theyre working to develop a new painkiller that packs 10 times the amount of medicine currently found in Vicodin, RTV6's Stacia Matthews reported.The San Diego-based pharmaceutical company Zegenix is close to releasing the drug Zohydro in 2012.If the Federal Drug Administration approves the new pain killer, it will be the first time patients can legally buy pure hydrocodone."(Zohydro) does not have acetaminophen with it. We don't have to worry about liver toxicity," pharmacist Cindy Burns said.Burns said some medical experts are critical of the drug because abusers could crush the time-released pills for an immediate, intense high.Officials with the National Coalition Against Drug Abuse said Zohydro could be the next OxyContin.We just don't need this on the market, NCADA officials said.Experts said OxyContin is the most abused medicine in the U.S."It's going to cause more respiratory and cardiac depression. If people are abusing it, it is more likely to have fatal side effects, Burns said. The chance for building up tolerance and addiction can be higher, the stronger the medication is.Officials with the Centers for Disease Control and Prevention said hydrocodone abuse sent more than 86,000 people to the emergency room in 2009.Burns said the new painkillers are likely to be more closely controlled and patients will have to get refills from their doctors.