How effective are supplementary doses of opioids for dyspnea in terminallyill cancer patients? A randomized continuous sequential clinical trial

Supplementary doses of opioids are recommended to relieve dyspnea in termin ally ill cancer patients. We conducted a randomized continuous sequential c linical trial to evaluate their efficacy. We recruited 33 terminally ill ca ncer patients from three palliative care centers, all of whom had persisten t dyspnea after rest and treatment with oxygen. Patients formed 15 successi ve pairs matched on route of administration. Within each pair, the order of allocation was randomly assigned, one patient receiving 25%, the other 50% of his 4-hourly opioid dose. Five measurements of dyspnea intensity and re spiratory frequency were made during 4 hours of follow-up. For each pair, a preference was attributed to the more effective regimen. The two regimens received an almost equal number of paired preferences (8 vs. 7). Overall, b oth mean dyspnea intensity and respiratory frequency decreased significantl y relative to baseline. Dyspnea reduction was relatively greater in patient s with initially low and moderate dyspnea intensity. In. terminally ill can cer patients with persistent dyspnea, 25 % of the equivalent 4-hourly dose of opioid may be sufficient to reduce both dyspnea intensity and tachypnea for 4 hours. (C) U.S. Cancer Pain Relief Committee, 1999.