For late-stage, advanced illness patients who develop constipation due to their need for opioids on a continuous basis, there may now be some relief. Wyeth Pharmaceuticals has announced the approval of methylnaltrexone bromide (Relistor), a new drug that works by blocking opioid entrance into the bowel cells, allowing them to continue to function normally. The new product is administered as needed, but the dose should not exceed one injection in a 24-hour period and should not be used in patients with known or suspected intestinal obstructions. The efficacy and safety of methylnaltrexone was conducted in two studies involving 287 patients over a four-month period. Patients receiving the drug experienced a significantly higher rate of elimination than those receiving placebo.