Greater Use of Food Poison as Muscle Relaxant Urged : Medicine: U.S. panel says botulinum toxin can aid spasm disorders such as stuttering and writer’s cramp. It could affect hundreds of thousands.
A federal advisory panel Wednesday recommended the expanded use of botulinum toxin for certain muscle spasm disorders, saying that injections of minute amounts of the lethal substance can be a safe and effective therapy for hundreds of thousands of Americans.
“We’ve seen . . . impressive evidence that this is the first choice of treatment for several disabling disorders,” said the panel chairman, Roger Duvoisin, chief of the department of neurology at the Robert Wood Johnson Medical School in New Brunswick, N. J. “Because of the high success rates of the toxin treatment, thousands more patients have the potential to lead improved lives.”
There has been “a long history of poisons becoming adaptive for medicinal purposes,” he said, and he quoted a line from Shakespeare’s “As You Like It”: “Sweet are the uses of adversity.”
Botulinum toxin, most commonly known as the cause of an often-fatal food poisoning, has been studied for nearly a decade as a treatment for temporarily relieving isolated muscle spasm disorders. These include involuntary contractions of the eyelids, misalignment of the eyes and facial spasms. “It has given relief where little was available before,” Duvoisin said.
Earlier this year, the Food and Drug Administration approved the use of the toxin for the treatment of those afflictions.
But the panel, convened by the National Institutes of Health, recommended that the toxin also be used for treating vocal cord spasms and neck spasms. It called the substance a promising therapy for stuttering and numerous other spasms--known as dystonias--including those of the mouth, jaw and limbs.
Even though those disorders are not life-threatening, Duvoisin said, “imagine, for example, what it would it be like if you couldn’t keep your eyes open.”
Until recently, conventional therapy for many of the disorders included “minimally effective drugs” or surgical procedures “designed to denervate or destroy the involved muscles,” the panel said. These treatments have been “generally unsatisfactory.”
Reports of the benefits of botulinum toxin “have thus aroused great interest and hope among physicians, biomedical scientists and patients,” the panel said.
The panel said that the toxin could be administered “to musicians, typists and others whose careers may be jeopardized by musician’s cramp or writer’s cramp.”
“Hundreds of thousands of Americans are affected by these disorders and are potential candidates for therapy,” the panel added.
The substance works by chemically blocking the connection between the nerve and the target muscle, essentially weakening the muscle. Small amounts used in therapy relax the muscle, thus reducing the spasm and allowing the patient to move more freely. Larger amounts of the toxin--as in botulism poisoning--can cause paralysis and death.
The effect of the botulinum toxin is temporary and usually lasts several months, meaning that repeated injections are required to sustain the benefits over a long period of time.
For that reason and others, the panel said that botulinum toxin therapy is not a cure for chronic neurological disorders, such as Parkinson’s disease. But it called for further research to determine its value in that area, as well as in treating cerebral palsy and spasticity in multiple sclerosis and urinary and anal sphincter dysfunction.
The panel said that serious side effects from the use of the drug are rare but that the long-term impact of chronic treatment is unknown. It recommended prolonged follow-up for patients on the therapy and urged that a national database of these patients be established.
Thus far, the therapy has been administered only by highly specialized physicians in academic medical centers, the panel said.
“We are stressing that physicians using this should have training in the use of the drug and be capable of handling complications should they arise,” Duvoisin said.
