Myasthenia gravis is a chronic neuromuscular disorder that results in muscle weakness of the voluntary muscles. This means that the muscles which control eye movements, swallowing, facial expressions, legs, arms and trunk are most affected. In some cases individuals may suffer from muscle weakness of the muscles which control breathing but this happens only if they also are experiencing another illness.
Treatment for myasthenia gravis normally includes factors from lifestyle changes, medications, surgical interventions and other treatment protocols currently under investigation.
Medications for myasthenia gravis fall into several different categories. The first category of medications are anti-cholinesterase inhibitor drugs such as Mestinon, Mytelase Caplets, Prostigmin and Regonol. These are typically the first line of treatment which boost the amount of acetylcholine available for neuromuscular transmission. They work by a stopping the breakdown of acetylcholine at the neuromuscular junction.
Effects of the medication can begin as early as 15 to 30 minutes after taking the first dose and benefits may last for up to four hours. For this reason some of the medications are taken three times a day while others are taken every 12 hours or once a day.
Slow release forms of medications which have delayed absorption and therefore a longer time of action are currently available. Unfortunately, slow release is not a choice for daytime use because release is variable based on food eaten during the day. Some patients use this preparation at night to avoid significant weakness they suffered during the morning periods.
Some of the medications can be given intravenously if oral medications cannot be used. This option is usually used during hospitalization during a myathesnic crisis when a patient is having difficulty breathing.
Another medication category which may be tried is immunosuppressive drugs such as prednisone, cyclosporin or azathioprine. These medications improve muscle strength by suppressing the production of abnormal antibodies, one of the causes of myasthenia gravis. However, they should be used carefully because they can cause major side effects if the dosing amount is not appropriate.
is one of those immune suppressing medications that helps the body fight infections. It is used to prevent the body from rejecting liver or kidney or heart transplants and can be given with cyclosporine. It can be used off label in patients who have myasthenia gravis. Two other medications that are also used off label are Azasan and Imuran. Using a drug off label means that the medication has been approved by the FDA for use in humans but it hasn’t been approved for use in this particular disease. Doctors have the ability to use some medications off label for specific diseases.
Individual who do have myasthenia gravis should avoid the use of some medications. The first medication to avoid is D-penicillamine and alpha interferon because these medications will actually trigger myasthenia gravis.
Researchers have also reported an increased weakness in a significant number of patients who use neuromuscular blocking agents such as succinylcholine and vecuronium which should only be used as an anesthesia with a physician familiar with myasthenia gravis. Quinine, quinidine or procainamide are also drugs which must be avoided as well is selected antibiotics particularly the aminoglycosides, telithromycin and ciprofloxacin.
The list of medications to avoid also includes beta-blockers such as propranolol or even eyedrops which include propranolol . Calcium channel blockers and iodinated contrast agents used for x-rays round out the list of medications that should not be used by individuals with myasthenia gravis.
Myasthenia Gravis Foundation of America: Medications and Myasthenia Gravis
National Insitute of Neurological Disorders and Stroke: Myasthenia Gravis Information Page
MayoClinic: Myasthenia Gravis
Drugs.com: Myasthenia Gravis Medications