[Clinical pharmacology of opioid analgesics].

Opioids are essential for analgesia and part of a multifarious group of drugs. The study of the endogenous opioid system and its receptors contributes to a better understanding of the advantages and disadvantages of opioids and to develop possibilities for optimization of new substances. Interactions with the different opioid receptors and the non-opioid effects are important aspects that increasingly need to be considered in the treatment design to ensure safe and effective pain management.