Myasthenia gravis

Myasthenia gravis is an autoimmune disorder, which is diagnosed in about 1 in 20 000 people every year in the United Kingdom, mainly affecting women between 20 and 40 and men over 50. In myasthenia gravis, normal communication between nerve and 

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Adrenocortical insufficiency Organ transplants Liver disease Adrenogenital syndrome Nephrotic syndrome Acute spinal cord injury Hyp ere alemia Hematologic disorders Myasthenia gravis Neoplastic disease... 

StmcturaHy related to nitrofurantoias are Dantrolene [7261-97-4] (38), a peripherally acting muscle relaxant, and its analogues (39), which can be used as an antidote against succiaylcholine-iaduced myopathy and ia autoimmune myasthenia gravis therapy (136,137). 

The anainoacridines, tacrine (19) and its 1-hydroxy metaboUte, velnacrine (20), are reversible inhibitors of AChE. Tacrine was synthesi2ed in the 1940s and has been used clinically for the treatment of myasthenia gravis and tardive dyskinesia (115). Placebo-controUed studies have indicated modest efficacy of tacrine to treat AD dementia (122,123) and in 1993 the dmg was recommended for approval by the PDA under the trade name Cognex. Tacrine (19) has been shown to interact with sites other than AChE, such as potassium channels (124) and muscarinic receptors. However, these interactions are comparatively weak and are not thought to contribute to the biological activity of the dmg at therapeutic levels (115). 

Autoantibodies are directed against nicotinic acetylcholine receptors in myasthenia gravis, resulting in receptor loss, skeletal muscle paralysis, and dysfunction (100). In addition, antibodies directed against voltage-gated Ca " channels produce similar neuromuscular dysfunction of Lambert-Eaton... 

The relative inaccessibility of physostigmine led to molecular dissection studies to define the parts of the molecule necessary for activity. A surprisingly simple derivative of m-hydroxy-aniline, neostigmine (40), proved to have the same activity as the complex heterocyclic molecule. In addition, this drug has found use as a cholinsterase inhibitor in pathologic conditions such as myasthenia gravis, marked by insufficient muscle tone. Reaction of m-dimethylaminophenol (37) witn pnosgene affords tne... 

Also, the outcome covers a large spectrum. Autoantibodies can specifically block an important protein (such as the gastric intrinsic factor required for the uptake of orally taken vitamin B12), or the receptor for —> acetylcholine (as in myasthenia gravis), but also can... 

Neurological diseases myasthenia gravis, multiple sklerosis, Guillain-Barre-syndrom... 

OPs or carbamate esters are potent inhibitors of both AChE and BChE. These include drugs (e.g. for AD or myasthenia gravis, MG), pesticides, insecticides and... 

ChEI treatments have been expanded also to include other dementias and CNS disorders, e.g. delirium, traumatic brain injuries and memory impairments, as well as myasthenia gravis, glaucoma and parasite infections. 

It is important to use these drag with caution in patients with a history of gastrointestinal disorders, renal disease, or liver impairment. The neuromuscular blocking action of die lincosamides poses a danger to patients widi myasthenia gravis (an autoimmune disease manifested by extreme weakness and exhaustion of die muscles). 

The major uses of the cholinergic drugp are in the treatment of glaucoma, myasthenia gravis, and urinary retention. 

Myasthenia gravis is a disease tiiat involves rapid fatigue of skeletal muscles because of die lack of ACh released at die nerve endings of parasympathetic nerve fibers. Drugs used to treat this disorder include ambeno-nium (Mytelase) and pyridostigmine (Mestinon). 

MYASTHENIA GRAVIS. Once dierapy is under way, the nurse must document any increase in the symptoms of die disease or adverse drug reactions before giving each dose of the drug. The nurse assesses the patient for the presence or absence of die symptoms of myasdienia gravis before each drug dose In patients witii severe... 

Mr. Hopkins, aged 32 years, has myasthenia gravis. Explain to Mr. Hopkins the symptoms he should be aware of that would indicate toxicity. 

All antiarrhythmic dra are used cautiously in patients with renal or hepatic disease. When renal or hepatic dysfunction is present, a dosage reduction may be necessary. All patients should be observed for renal and hepatic dysfunction. Quinidine and procainamide are used cautiously in patients with CHF. Disopyramide is used cautiously in patients with CHF, myasthenia gravis, or glaucoma, and in men with prostate enlargement. Bretylium is used cautiously in patients with digitalis toxicity because the initial release of norepinephrine with digitalis toxicity may exacerbate arrhythmias and symptoms of toxicity. Verapamil is used cautiously in patients with a history of serious ventricular arrhythmias or CHF. Electrolyte disturbances such as hypokalemia, hyperkalemia, or hypomagnesemia may alter the effects of the antiarrhythmic dru . Electrolytes are monitored frequently and imbalances corrected as soon as possible... 

Johns RJ, McQuillen MP. 1966. Syndrome simulating myasthenia gravis Asthenia with anticholinesterase tolerance. Ann NY Acad Sci 135 385-397. 

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