[Opioids for cancer pain treatment. Efficacy and side effects].

In Germany, about 400,000 people per year are diagnosed with cancer. In the terminal stage of their disease, up to 95% of cancer patients suffer from pain. In earlier stages, this is true for about 50% of patients. It is estimated that 220,000 people in Germany are in need of cancer pain therapy. If the pain therapy is going to be changed, this must be comprehensively discussed with the patient in advance, particularly when strong opioids are used which are mostly indicated in these patients. Opioids are effective and reliable drugs when pain therapy is performed according to the basic principles. It is widely agreed that the WHO analgesic ladder serves as orientation and that the choice of substances must be suited to the cause and pathophysiological type of pain. Even though a variety of other strong opioids is in clinical use, morphine remains the reference substance for efficacy and occurrence of side effects in opioids.