Chapter 11
- Intravenous Opioid Anesthetics
- Kazuhiko Fukuda
The term opioid refers broadly
to all compounds related to opium. The word "opium" is derived from opos,
the Greek word for juice, the drug being derived from the juice of the opium poppy,
Papaver somniferum. Opiates are drugs derived from
opium, and include the natural products morphine, codeine, and thebaine and many
semisynthetic congeners derived from them.
The first undisputed reference to opium is found in the writings
of Theophrastus in third century BC. During the
Middle Ages, many of the uses of opium were appreciated. Opium contains more than
20 distinct alkaloids. In 1806, Sertürner reported the isolation of a pure
substance in opium that he named morphine, after Morpheus, the Greek god of dreams.
By the middle of the nineteenth century, the use of pure alkaloids rather than crude
opium preparations began to spread throughout the medical world.
In addition to the remarkable beneficial effects of opioids, the
toxic side effects and addictive potential of these drugs also have been known for
centuries. Synthetic opioid analgesics without side effects were explored, but many
of the synthetic opioids share the side effects of natural opioids. The search for
new opioid agonists led to the synthesis of opioid antagonists and compounds with
mixed agonist/antagonist properties, which expanded therapeutic options and provided
important tools for exploring mechanisms of opioid actions. Furthermore, new methods
of opioid administration, including patient-controlled analgesia (PCA) and computer-based
infusion techniques, have been developed.
