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| |  Botox Reduces Effects Of Cervical Dystonia ORLANDO, FL -- November 17 -- Treatment with Botox® (Botulinum Toxin Type A) is shown to be highly effective in the treatment of cervical dystonia, a disorder that causes abnormal movements and severe pain in the head and neck regions, as indicated by new research presented at the International Conference 1999: Basic and Therapeutic Aspects of Botulinum and Tetanus Toxins held at Orlando, Florida. Several presenters delineate differences in duration of treatment, efficacy, and safety of botulinum toxin type A and type B.
"Treatment with current Botox offers new promise to people who suffer from the disabling effects of cervical dystonia," said Dr. Robert Hauser, University of South Florida, Tampa. "Our research shows that this treatment provides patients with significant improvement in head positioning and ability to function and reduced pain. Our goal is to help these patients live more comfortable and productive lives." Cervical dystonia is typified by involuntary contractions of the muscles in the neck which cause twisting and repetitive movements or abnormal postures of the head. During the past ten years, botulinum toxin type A (BTX-A) injected into the muscle has become the standard therapy for most patients with cervical dystonia. In a presentation by a lead investigator from Rush Medical College, Chicago, IL clinical study results showed that 70 to 90 percent of patients improve following injection with BTX-A, reporting improvement of resting posture of the head, pain and head mobility. Adverse effects are often mild and transitory and do not prevent continued use of BTX-A.(1) A multi-center trial including Robert Hauser, MD, of the University of South Florida, Tampa, FL concluded that BTX-A provided a significant, sustained benefit vs. placebo for the treatment of cervical dystonia measured by head position, pain and disability assessments.(2) An important difference between the current formulation and the original Botox is that the current Botox contains a minimal amount of protein, only 5ng per 100 unit vial. Other studies presented at the meeting confirm that the safety and efficacy of the original and current formulation of Botox are the same. -- Dr. Markus Naumann, of the University of Wurzburg, Wurzburg, Germany, showed that current Botox was as effective and safe as original Botox in the treatment of cervical dystonia. (3) -- The efficacy and safety of current Botox were shown to be comparable to the original in treatment of cervical dystonia in a study by Dr. Joseph Jankovic, of Baylor College of Medicine, Houston, TX. In addition, current Botox lowers the patient's exposure to neurotoxin complex protein and may result in reduced antigenicity compared to original Botox(4) -- Preliminary results from an ongoing study, headed by Dr. Mitchell Brin of developed resistance after 18 months, suggesting that minimizing patient exposure to protein may reduce antibody formation and help patients to continue to receive benefit over the long term.(5) There are seven different botulinum toxin serotypes. Each serotype has distinct properties and actions. No two serotypes are alike. Molecular differences between the serotypes and their formulations cause each toxin to have a different therapeutic profile. In addition, there are also variations within each serotype. This explains why there are dramatic differences between Botox and botulinum toxin type B (BTX-B) in potency, duration, safety and antigenic potential. Some of the differences identified in patients with cervical dystonia are the following: BTX-A has a clinically proven treatment effect of 12 to 16 weeks,(6,7) although some patients may respond up to six months following injection. Published clinical studies on BTX-B (in patients still responding to treatment with BTX-A) showed a treatment duration effect vs. placebo of eight weeks.(8) The main cause of an antigenic response in patients is exposure to high levels of neurotoxin protein which can result from either increased dosing or frequent injections of the toxin. Treatment with Botox greatly reduces the potential for antigenicity because it exposes patients to the lowest protein level possible (5ng protein per 100 units) while still delivering a successful treatment result.(9) Although each serotype is distinct, some types may have certain characteristics in common. These common characteristics can create a cross reactivity between patients who have developed antibodies to either BTX-A and BTX-B. In studies, dry mouth, an anticholinergic (systemic) effect has been commonly reported (up to 44 percent of patients) as an adverse effect of botulinum toxin Type B.(10,11) Dry mouth has not been tied to BTX-A use. "Type A has been the gold standard of botulinum toxins for ten years," commented Dr. Hauser. "The data suggest Type A will continue to serve most patients' needs, but we're certainly excited by the prospect of having Type B available for patients proven resistant to type A." Botox works by blocking the excessive release of acetylcholine from the peripheral nerve terminal at the neuromuscular junction (where the nerve transmits signals to the muscle). The affected terminals are inhibited from stimulating muscle contraction, resulting in muscle relaxation. Over a period of several months, the beneficial effects gradually fade. Side effects of treatment with Botox are usually transient and mild to moderate in nature. A highly stable, purified form of botulinum toxin type A is currently marketed in the U.S. under the brand name Botox by Allergan, Inc. for the treatment of strabismus and blepharospasm associated with dystonia (disorder of the eye muscle that controls blinking). Researchers across the country are also studying its uses in a number of other disorders including cervical dystonia (involuntary muscle spasms in the neck and shoulders), post-stroke spasticity, back pain, migraine and tension headache.
References 1 "Botox for Cervical Dystonia," platform presentation by C. Comella at International Conference 1999: Basic and Therapeutic Aspects of Botulinum and Tetanus Toxins, Kissimmee, Florida, November, 1999. 2 "A Randomized, Multicenter, Double-Blind, Placebo-controlled Study of original Botox (Botulinum Toxin Type A) Purified Neurotoxin Complex for the Treatment of Cervical Dystonia," by R.A. Hauser, MD. Presented at the International Conference 1999: Basic and Therapeutic Aspects of Botulinum and Tetanus Toxins, Kissimmee, Florida, November, 1999. 3 "A Prospective Comparison of the Efficacy and Safety of Current US BOTOX (Botulinum Toxin Type A) and Original US Botox in the Treatment of Cervical Dystonia," by M. Naumann. Presented at the International Conference 1999: Basic and Therapeutic Aspects.
Related Links: Allergan, Inc.
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