Introduction

Opioids have a long history in the clinical setting. Being old, however, does not necessarily mean being well known or even liked by the majority of clinicians. Opioids are usually prescribed in too low doses, and physicians' prescriptions are often even more reduced by the nursing staff (Atchison et al., 1991; Juhl et al., 1993; McCormack et al., 1993; Stratton Hill, 1993; Oates et al., 1994; Stevens et al., 1995; Whippie et al., 1995). In the author's experience, there are mainly two reasons for the hesitation of health-care personnel to use adequate opioid dosages, and, interestingly, they differ, whether one deals with general practitioners or hospital doctors. The first group is concerned with tolerance and addiction (which is not justified in pain patients; however, the subject is beyond the scope of this chapter) and the second with the vital risk of respiratory depression. It is hard to understand why two groups of medical experts share the same concern but for different reasons. The only explanation is that both groups have hardly ever had an adequate education in the field of pain and/or opioid analgesics. It was the development of a new analgesic technique, patient-controlled analgesia (PCA), that greatly increased our knowledge of the clinical effects of opioids, particularly in patients suffering from painful conditions, a group that differs quite obviously from the volunteers from whom most older pharmacology textbooks derived their conclusions.