Werner Kalow (1917–2008)
Succinylcholine is an excellent choice of poisons, because it breaks down rapidly in the body and leaves few traces. In the 1960s, Carl Coppolino, a New Jersey anesthesiologist, was accused but acquitted of using succinylcholine to murder his lover’s husband. He was subsequently convicted of using the same drug to fatally poison his wife.
During surgery—particularly surgery involving the abdomen—drugs are used to relax muscles. Voluntary muscles become flaccid, causing whole-body paralysis. Breathing muscles are also paralyzed, and breathing must be maintained artificially using a mechanical respirator. Tubocurarine-like drugs are used to produce muscle relaxation over periods that often exceed thirty minutes, but sometimes it is only necessary to relax muscles for several minutes. Common procedures that require short-term paralysis include preventing the gag reflex when a breathing tube is inserted into the trachea. Brief muscle relaxation also prevents convulsions and possible fractures of the spine during electroconvulsive shock therapy used to treat severe depression.
Succinylcholine (suxamethonium, Anectine) produces muscle relaxation within one minute of an injection, and its effects on breathing and muscle paralysis usually persist for only three to five minutes. Usually, but not always. Normally, succinylcholine is very rapidly broken down and inactivated by pseudocholinesterase, an enzyme present in the plasma. However, about one in 3,000 individuals has a genetic abnormality involving a defective form of pseudocholinesterase. For those people, succinylcholine produces paralysis and an inability to breathe unassisted for two hours or longer. The study of the genetic basis for our different responses to drugs, pharmacogenetics, is now one of the hottest areas of drug research. A pioneer in this field was Werner Kalow. Kalow served in the German navy during World War II, was a prisoner of war in Arizona, and in 1951 became professor of pharmacology at the University of Toronto. There he studied, in detail, the pharmacogenetics of succinylcholine, inspired by a patient’s death from this drug.
SEE ALSO Tubocurarine (1935), Drug Metabolism (1947), Isoniazid (1951).
Succinylcholine is a very short-acting muscle relaxant used primarily for insertion of breathing tubes and laryngoscopes.