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Written by Louis H. Weimer, MD, Clinical Professor of Neurology, Co-director Columbia Neuropathy Research Center, Columbia University Medical Center This fact sheet is intended to alert patients with Charcot-Marie-Tooth about medications that might worsen their neuropathy and be harmful to their strength, sensation, and function. Of the thousands of recognized medications, only a small number are known to damage ner ves or cause neuropathy. Most of these drugs fall into two broad categories: chemotherapies or antibiotics, but numerous other treatments are also known to cause ner ve injur y. While there are notable exceptions, most examples of toxic neuropathy produce damage to sensation or pain ner ves and have lesser effects on motor or strength ner ves. The nerves of individuals with neuropathy from any long the agent stays in the body. For example, the heart cause, including CMT, may be more vulnerable to certain drug amiodarone may take several months to clear conditions and stresses such as toxins and certain medi- one’s system. Alternatively, some medications may carry cations than other people’s nerve. The list of potentially excessive concern only because they are used so widely, toxic medications can be divided by the relative likeli- such as statins and certain stomach acid blockers. The hood or risk of causing a problem. Some medications decision to stop a treatment to see if improvement occurs are well known to cause toxicity, while others have been must be weighed against the benefits of treatment. found to cause neuropathy only rarely. For a handful of medications, evidence of toxicity is controversial, doubt- For most drugs listed, the risk of exposure must be weighed against the benefit of use, including the severity of the treated condition, available alternative treat- Other factors may further influence whether a treatment ments, and drug effectiveness. There is only one example is tolerated or not, including other medical conditions, of a treatment that must be avoided in all circumstances. especially diabetes, kidney failure, or alcohol abuse. This exception is the chemotherapy treatment vincristine Establishing a clear causative link between medication that may cause severe weakness and nerve injury after use and increased symptoms or nerve loss is not always only 1 or 2 doses in patients with minimal or unknown simple. Worsening nerve function very soon after starting CMT1A, the most common form. This medication carries a new drug is very suspicious, especially if the medication a “black box” warning by the Food and Drug Administra- is of high concern. However, some agents may cause tion (FDA) against use in CMT patients or in patients that problems only after extended use, for example the antibi- might have CMT (e.g., relatives of individuals with CMT). otics metronidazole and linezolid. Toxicity of this type after Virtually all other treatments carry a relative but not abso- lute risk of use. There is no proven link between worsening neuropathy and anesthesia or vaccinations, although When problems appear immediately after starting a some claim increased symptoms following these events. new treatment or medication, it is important to see your In most but not all instances the condition prevented by doctor as soon as possible. One would expect symptoms a vaccination is much worse than the consequences of or function to improve after the drug is stopped; the injection. It is important, however, to always discuss however, improvement may be delayed by weeks or any known family history of CMT with your health care months depending on the degree of injury and how provider, particularly your anesthesiologist.
T h i s p u b l i c a t i o n w a s s u p p o r t e d b y C o o p e r a t i v e A g r e e m e n t 1 U 3 8 D D 0 0 0 713 - 01 f r o m t h e C e n t e r s f o r D i s e a s e C o n t r o l a n d P r e v e n t i o n . I t s c o n t e n t s a r e s o l e l y t h e r e s p o n s i b i l i t y o f t h e a u t h o r s a n d d o n o t n e c e s s a r i l y r e p r e s e n t t h e o f f i c i a l v i e w s o f t h e C e n t e r s f o r D i s e a s e C o n t r o l a n d P r e v e n t i o n .

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