Opioids in Respiration and Vomiting

The respiratory depression induced by opioids is the main adverse reaction limiting their therapeutic potential as analgesics. If respiratory function is preserved artificially, much higher doses of opiates are used to reach complete analgesia and even anesthesia. Apnea is also known to be the most frequent cause of death after opiate overdosage. This respiratory depression is a dose-dependent and consistent effect of most opiate drugs, regardless of their origin or structure. Thus the widely accepted principle in therapy is that equianalgesic doses of opiates induce comparable respiratory depression (see KEATS 1985). A number of accurate methods are now available not only to quantify respiratory depression, but also to detect alterations in the regulation of breathing which may indicate the potential for serious depressions to occur (JORDAN 1982).