RELISTOR a new option for treating constipation due to opioids

Almost all patients on chronic opioids get constipation due to decreased GI motility. Sometimes this is more uncomfortable than the pain that is being treated.
Relistor (methylnaltrexone) is an opioid antagonist like naltrexone. The methyl group keeps it from crossing into the CNS. This allows Relistor to block opioid effects in the CNS.
For now , Relistor is only for palliative care patients who are not getting relief from laxatives. It is given SC every other day, as needed. It usually works within 4 hours and most side effects are mild such as nausea, dizziness, and diarrhea.
Patients starting chronic opioids should get a stool softner plus stimulant laxative such as Senna, bisacodyl tablets.