Some 5,700 boxes of injectable morphine distributed to Canadian hospitals were being recalled Thursday after mislabeling was discovered in a Toronto hospital. The federal Health Canada agency issued an urgent directive for hospitals nationwide not to use morphine sulphate injections manufactured by Sandoz Canada, the QMI Agency reported. One box was discovered at an undisclosed Toronto hospital in which two glass ampoules in a box labeled morphine actually contained isoproterenol hydrochloride, which is an adrenalin-like drug injected during cardiac arrest, the National Post reported. If that drug were injected instead of morphine, potentially life-threatening rapid heartbeat or irregular heartbeat could result, the regulator said. \"Health Canada is working urgently with Sandoz Canada to determine the scope of the issue and to ensure that other incorrectly packaged product, if any, does not make it into the drug supply system,\" the agency said in a statement. It wasn\'t immediately known if any patients was administered the wrong drug, the agency said.