Poison from puffer fish may prove to be new painkiller for palliative patients

Cancer patients may soon have a new drug to help control their pain. The Capital Health region is participating in a national study researching a deadly toxin that may prove to be an effective painkiller. Currently in its second phase of testing in Canada, this toxin is derived from the poison found in puffer fish.

Extracted from the liver, testes, ovaries and eggs of the puffer fish, or blow fish, the toxin was originally developed and tested to help heroin addicts get through their withdrawal when researchers discovered how effective the drug was as a pain killer.

Palliative Care physician Dr. Doreen Oneschuk is one of the participating researchers in the study and works with terminal patients at the Grey Nuns Community Hospital’s Tertiary Palliative Care Unit. Dr. Oneschuk says this study is quite exciting. “It has been a while since we’ve had something that is new for pain relief.” Dr. Oneschuk says if in fact this proves to be safe and effective, it’s going to offer the person with cancer another alternative for pain management.

Up to 90 per cent of cancer patients experience pain from cancer or its treatment. Severe pain can be devastating for the patient and their loved ones. It can dramatically impact their quality of life, add to the overall burden of the illness, and interfere with their recovery.

The toxin is a sodium channel-blocking compound, which acts to put brakes on electrochemical nerve-signal transmission and reduce pain. What makes it different from other anesthetics and painkillers is that it appears the toxin does not yield side effects associated with other drugs including dependency and drowsiness. “The most common side effect usually is numbness and tingling, either around the mouth or in the arms and legs, but otherwise it tends to be quite well tolerated,” says Dr. Oneschuk.

The study will be open until 36 patients are recruited. The research will then enter its third phase, which will focus on the toxin’s effectiveness within the clinical population as manufacturers offer the painkiller to a wider spectrum of patients.

Criteria for a patient to be admitted into the study are strict. There is a lengthy list of exclusion criteria and patients must have a poor response to more traditional pain treatment.

Oneschuk says she thinks the research company is pleased with the trial so far. “To date, about half the patients in the study have obtained some degree of pain relief and this percentage might improve as the doses go higher in this multi-dose study.”

The practice of pain management will continue to grow and be the focus of future research, as the need for Palliative Care grows, especially due to increasing mortality from cancer. Approximately one in three Canadians will be diagnosed with cancer and of those, about 50 per cent will die from it. During this decade, a 42 per cent increase in cancer mortality is expected, together with increases in deaths from other chronic incurable illnesses.

More information on pain management and other areas of Palliative Care is available to health care professionals and the public at www.palliative.org

Members of the Capital Health Regional Palliative Care program are committed to education and research in pain management and all aspects of end-of-life care. For their colleagues both in and out of region, Capital Health and Caritas Health Group put on an annual conference. The theme of this year’s Education & Research Days is “Reflections on Dignity in Palliative Care” and will be held October 20 & 21, 2003. Conference information is available from (780) 482-8081 or by emailing pallconf.gnch@cha.ab.ca Edmonton has also been chosen to host the 2005 National Palliative Care Conference.