NEW YORK, Dec 04 (Reuters Health) -- Botulinum toxin, more commonly known as 'botox,' is used as both a treatment for various neuromuscular disorders and as a way of smoothing wrinkles. However, one expert has reported a case of myasthenia gravis, a potentially life-threatening paralysis, that appears to have been exacerbated by a botox injection.
"Doctors should be aware that this can occur, and does indicate a contraindication for the use of botulinum toxin," said Dr. Gary Borodic, an associate professor at Harvard Medical School and author of a case study published in the December 5th issue of the journal The Lancet.
The report describes the case of an 80-year-old female patient suffering from a recurrent facial tic. Botulinum toxin is often used in the treatment of uncontrolled facial spasms, since it produces a temporary, localized paralysis of the affected area.
The woman received 18 botox injections over a period of 13 years "without any untoward effects," Borodic writes. However, he notes that "4 days after her 19th injection... she had severe difficulty swallowing and paralysis of her cervical (neck) muscles, having to hold her head up to face the examiner, and complete bilateral facial paralysis."
Blood tests revealed that the patient had high levels of antibodies to acetylcholine receptors, a feature of myasthenia gravis. In an interview with Reuters Health, Borodic stressed that the patient's myasthenia was not actually caused by the drug, but appears to have been aggravated by the botox injection.
Treatment with two drugs, mestinone and predisone, helped relieve her symptoms, and the patient was released from the hospital after 10 weeks.
Borodic said he does have "concerns with off-label uses (of botulinum toxin), however." He explained that "if the drug is being used wide-scale by cosmetic surgeons, these are people who may not normally see myasthenia gravis because they don't normally have to deal with the disease." Borodic hopes that cosmetic surgeons will become more aware of the "rare" possibility that the medication can exacerbate myasthenia gravis symptoms.
Dr. Stephen Jenkins, director of botulinum toxin clinical trials for Allergan Inc., of Irvine, California, which distributes botox, described the Boston case as "rare, very unusual and not likely to be frequently repeated." In an interview with Reuters Health, he noted that in this case, botox appears to have "exacerbated a subclinical situation."
"Clearly, (in) a patient that you know has a history of myasthenia gravis, you shouldn't be using botox," he added.
SOURCE: The Lancet 1998;352:1832.
