Prevention of opioid side effects.

Physician education in cancer pain management is seriously deficient. Many problems occur with opioids simply because of therapeutic ignorance. Opioid side effects are best prevented by using morphine as the drug of first choice for severe pain. Anticipation and prevention of opioid side effects avoids most problems. Physicians need to be aware of how to transfer patients from one opioid to another or from one route of administration to another. Side effects common in clinical practice are constipation, nausea/vomiting, dry mouth, and sedation. The importance of the issues of tolerance, dependence, and respiratory depression have been exaggerated.