What if you could design a drug that has all the pain-relieving power of morphine but none of its dangerous or addictive side effects? Scientists have spent years trying to do just that, and on Wednesday, they unveiled one of their most promising compounds yet — a chemical concoction they dubbed “PZM21.” When tested in mice that were placed on a hot surface, PZM21 offered nearly as much pain relief as morphine and lasted for up to three hours. That’s “substantially longer” than morphine or other experimental drugs, the scientists wrote. Mice treated with PZM21 did not find it addictive, as evidenced by the fact that they were no more likely to return to a place where they got the drug than to visit a similar chamber where they could get a saline solution. Plus, while the animals became hyperactive after a dose of morphine — considered a sign of the drug’s addictive power — they remained perfectly calm after getting a comparable dose of PZM21. They also were less constipated, a side effect of certain opioid drugs. But the drug still isn’t perfect. Like morphine and other opioids, PZM21 caused mice to slow their breathing to dangerously low levels. However, their breathing improved before the drug’s painkilling properties wore off. That’s in contrast to morphine, which continues to cause respiratory depression even after it allows pain to return. http://www.latimes.com/science/la-sci-sn-drug-mimics-opioids-20160817-snap-story.html Paper
