Morphine Sulfate, classified as an opiod analgesic is being indicated to relieve moderate to severe acute and chronic pain; pain in patients who require opioid analgesics for more than a few days (sustained-release only); management of pain not responsive to nonnarcotic analgesics; dyspnea associated with acute left ventricular failure and pulmonary edema; preoperative sedation; adjunct to anesthesia; analgesia during labor; and most often to routinely relieve pain during and after cancer surgery.

US scientists say the opiate promotes the growth of new blood vessels which deliver tumours oxygen and nutrients. Thus making it healthier and promoting its spread and growth. This is somewhat alarming,  however, American Association for Cancer Research in Boston  claim to have found a drug which counters this effect.  Dr Patrick Singleton from the University of Chicago told the meeting of experts that in laboratory tests, morphine not only strengthened blood vessels but also appeared to make it easier for cancers to invade other tissues and spread. But he said this could be overcome by a drug – methylnaltrexone or MNTX – developed in the 1980s to prevent morphine-related constipation but only recently approved in the US. It appears to work without interfering with the pain-relieving properties of the opiate. “If confirmed clinically, this could change how we do surgical anaesthesia for our cancer patients,” said Dr Singleton.  “It also suggests potential new applications for this novel class of drugs which should be explored.” he added.

The tests were started after his colleague, anaesthetist Jonathan Moss, noted that several patients receiving this kind of opiate blocker survived longer than might be expected after surgery.

Research in this area is in the early stages, so it’s too early to tell whether opiate-based painkillers have an effect on cancer growth.Much more research would be needed to justify changing the way opiates are used to treat people with cancer.