Deadly poison may be helpful in treating cramps - botulinum toxin; involuntary muscle clenching

Nutrition Health Review, Spring, 1991

Deadly Poison May Be Helpful in Treating Cramps

Every few months seems to bring news of new medical success in using botulinum toxin - best known as a cause of lethal food poisoning - to treat involuntary clenching of muscles.

When physicians inject tiny amounts of the toxin it may be an effective treatment for spastic muscle conditions that affect the eyes, eyelids, throat, face, hands, and vocal cords. A National Institutes of Health committee reported recently that it also shows promise in the treatment of stuttering and of cramps experienced by musicians, writers, and typists.

Biochemist Edward Schantz follows these developments with interest and a measure of pride. An emeritus professor in the University of Wisconsin-Madison Food Research Institute, Schantz is the original source of all the botulinum toxin used in medicine in the United States and several other countries.

"With the approval of the FDA, doctors began using the toxin on human volunteers about 10 years ago," Schantz says. "Some of the spasms can be quite painful or debilitating, and this treatment gives patients relief."

For some spastic muscle disorders, injections of botulinum toxin are an alternative to surgery. For other conditions, the toxin - which works by partially paralyzing muscles - is the only effective treatment.

Medical reports indicate that several hundred thousand people in the United States suffer from various spastic muscle disorders treatable with the toxin, according to Schantz.

The toxin relieves a relatively common condition called blepharospasm, in which the eyelids of those afflicted close involuntarily, making it impossible to do such simple things as driving or reading. A minute amount of toxin injected into the eyelids of these individuals usually restores their vision and allows such individuals to lead a normal life, according to Schantz. He says individuals may need additional treatments later if new nerve connections to the muscles become established.

The toxin can also relieve the pain and restore normal functioning to people with facial spasms, which pull the face out of shape, and spasmodic torticollis, which the neck and shoulder muscles pull the head to one side.

In preparing the toxin for human use, Schantz had to meet standards set by the U.S. Food and Drug Administration. He prepared many milligrams of the toxin, carefully culturing the cells and purifying the toxin to make it suitable for human treatment. The toxin is so powerful that one milligram (a tiny fraction of an ounce) is enough to make a million doses for human use. That original batch remains the only FDA-approved source of toxin in the United States.

In 1983 Congress passed the Orphan Drug Law, which encourages the development of drugs to treat patients with relatively rare disorders. Scott subsequently applied for orphan drug status for botulinum toxin. In December, 1989, the FDA licensed botulinum toxin as an orphan drug, thus recognizing it for human treatment.