Curare

Image:Strychnos Toxifera by Koehler 1887.jpg Curare is a substance containing the alkaloidD-tubocurarine. It is obtained from one of several plants, the purified products of which are used as skeletal musclerelaxants. Curare has been superseded by a number of curare-like agents that have a similar pharmacodynamic profile but with fewer side effects.

Curare is an example of a non-depolarising muscle relaxantwhich blocks the acetylcholinereceptors on the post synaptic membrane of the neuromuscular junction.

Curare has also been used historically as a paralyzing poisonby South Americanindigenouspeople. The prey is killed by asphyxiationas the respiratory muscles are unable to contract resulting in apnea.

Curare and anaesthesia

Muscle relaxants are used in modern anaesthesiafor many reasons, such as providing optimal operating conditions and facilitating intubation of the trachea. Before muscle relaxants, anaesthesiologists needed to use larger doses of the anaesthetic agent, such as etheror cyclopropaneto achieve these aims. Such deep anaesthesia risked killing patients that were elderly or had heart conditions.

On January 23, 1942, Dr. Harold Griffithand Dr. Enid Johnsongave a synthetic preparation of curare (Intracostin) to a patient undergoing an appendectomy(to supplement conventional anaesthesia). Modern anaesthetists have at their disposal a variety of muscle relaxantsfor use as a standard component of anaesthesia.

The ability to produce muscle relaxation independently from anaesthesia has permitted anaesthesiologists to adjust the two effects as needed to ensure that their patients are safely unconscious and sufficiently relaxed to permit surgery. However, it has also made possible anaesthesia awareness, a condition in which, through error or accident, a patient remains fully conscious and sensitive to pain during surgery, but is unable to move and thus unable to alert attending staff to their state of awareness.

Plants from which curare can be extracted

• Strychnos toxifera
• Chondrodendron tomentosum

References

• Foldes, F.F. "Anesthesia before and after curare", Anasthesieabteilung des Albert-Einstein-College of Medicine. Anaesthesiol Reanim, 1993, 18(5):128-31. (retrieved June 20 2005)
• James, Mel. "Harold Griffith",Heirloom Series, Volume 6. (retrieved June 20 2005)
• "Curare", Blue Planet Biomes, 2000. (retrieved September 27 2005)

es:Curare fr:Curare nl:Curare pl:Kurara pt:Curare sv:Curare

This article is licensed under the GNU Free Documentation License.
It uses material from the http://en.wikipedia.org/wiki/Curare Wikipedia article Curare.