Synthetic Sea Snail Venom Eases Pain in AIDS, Cancer Patients, Study Says
Ziconotide, a synthetic form of sea snail venom manufactured by Elan Pharmaceuticals, can ease pain in patients with AIDS or cancer for whom other painkillers, such as morphine, have not been beneficial, according to a study published in the Jan. 7 issue of the Journal of the American Medical Association, the AP/Florida Times-Union reports (Tanner, AP/Florida Times-Union, 1/6). Dr. Peter Staats of the Division of Pain Medicine at Johns Hopkins University School of Medicine and colleagues gave either ziconotide or a placebo to 111 patients ages 24 to 85 who had cancer or AIDS and a mean Visual Analog Scale of Pain Intensity (VASPI) score of 50 mm or greater (Staats et al., Journal of the American Medical Association, 1/7). The medication was administered for 10 days through a small, battery-operated pump implanted in the patients' abdomens that delivered continuous doses of the medication into the fluid surrounding the spinal cord.
Approximately 53% of patients receiving ziconotide experienced moderate to complete pain relief, compared with 18% of patients randomized to the placebo group (AP/Florida Times-Union, 1/6). In addition, some patients in the ziconotide group were able to reduce their use of other pain medications while receiving the medication, while some patients in the placebo group had to increase their use of other painkillers (Rauscher, Reuters Health, 1/6). Although 22 ziconotide patients, compared with four in the placebo group, experienced serious side effects, study author Dr. David Ellis, medical director at Elan, said that subsequent research showed that starting patients on lower doses of ziconotide reduces their risk of serious side effects (AP/Florida Times-Union, 1/6). The FDA is currently reviewing ziconotide, which is being developed by California-based Neurex, according to Reuters Health (Reuters Health, 1/6). The study was co-funded by Elan and Medtronic, the company that manufactures the pumps that delivers the medication (AP/Florida Times-Union, 1/6).