Myasthenia gravis, edrophonium

The answer is a. (Hardman, pp 161-169.) Although all of the listed compounds inhibit the activity of the cholinesterases, only edrophonium chloride is used in the diagnosis of myasthenia gravis. The drug has a more rapid onset of action (1 to 3 min following intravenous administration) and a shorter duration of action (approximately 5 to 10 min) than pyridostigmine... 

The pronounced weakness that may result from inadequate therapy of myasthenia gravis (myasthenic crisis) can be distinguished from that due to anticholinesterase overdose (cholinergic crisis) by the use of edrophonium. In cholinergic crisis, edrophonium will briefly cause a further weakening of muscles, whereas improvement in muscle strength is seen in the... 

A young patient is being treated for myasthenia gravis, which requires frequent adjustment of the optimal dose of neostigmine. The patient is challenged with edrophonium to evaluate the effectiveness of the cholinesterase inhibition. Optimal dosing will be indicated by... 

Edrophonium Myasthenia gravis, ileus, arrhythmias 5-15 minutes... 

Edrophonium is sometimes used as a diagnostic test for myasthenia. A 2 mg dose is injected intravenously after baseline muscle strength has been measured. If no reaction occurs after 45 seconds, an additional 8 mg may be injected. If the patient has myasthenia gravis, an improvement in muscle strength that lasts about 5 minutes can usually be observed. 

Edrophonium is also used to assess the adequacy of treatment with the longer-acting cholinesterase inhibitors in patients with myasthenia gravis. If excessive amounts of cholinesterase inhibitor have been used, patients may become paradoxically weak because of nicotinic depolarizing blockade of the motor end plate. 

Edrophonium Alcohol, binds briefly to active site of acetylcholinesterase (AChE) and prevents access of acetylcholine (ACh) Amplifies all actions of ACh increases parasympathetic activity and somatic neuromuscular transmission Diagnosis and acute treatment of myasthenia gravis Parenteral quaternary amine does not enter CNS Toxicity Parasympathomimetic excess Interactions Additive with parasympathomimetics... 

Neostigmine Forms covalent bond with AChE, but hydrolyzed and released Like edrophonium, but longer-acting Myasthenia gravis t postoperative and neurogenic ileus and urinary retention Oral and parenteral quaternary amine, does not enter CNS. Duration 2-4 h Toxicity and Interactions Like edrophonium... 

Edrophonium Enlon, Reversol, Tensilon Myasthenia gravis, reversal of neuromuscular blocking drugs... 

The therapeutic uses of neostigmine include the treatment of atony of the urinary bladder and postoperative abdominal distention. In addition, it antagonizes the action of rf-tubocurarine and curariform drugs. Edrophonium, neostigmine, or pyridostigmine may be used to diagnose myasthenia gravis. Because edrophonium has the shortest duration of action, it is most often used for this purpose. 

The actions of edrophonium [ed roe FOE nee um] are similar to those of neostigmine, except that it is more rapidly absorbed and has a short duration of action (10-20 minutes). Edrophonium is a quarternary amine and is used in the diagnosis of myasthenia gravis. Intravenous injection of edrophonium leads to a rapid increase in muscle strength. Care must be taken since excess drug may provoke a cholinergic crisis. Atropine is the antidote. 

Efffect of edrophonium in a patient showing symptoms of myasthenia gravis. 

For myasthenia gravis, both to diagnose (edrophonium) and to treat (neostigmine, pyridostigmine, distigmine) To stimulate the bladder and bowel after surgery (bethanechol, carbachoi, distigmine)... 

Edrophonium is structurally related to neostigmine but its action is brief and autonomic effects are minimal except at high doses. The drug is used to diagnose myasthenia gravis and to differentiate a... 

Cerebrospinal flnid is normal in botnlism bnt nsnally abnormal with other causes of neurologic illnesses. Brain, spine, and chest imaging may reveal other causes of the neurologic symptoms, such as hemorrhage, inflammation or neoplasm (36). Myasthenia gravis patients with paralysis will obtain brief relief from a test dose of edrophonium chloride, whereas a close inspection of the skin may reveal the cause of tick paralysis (36). 

Edrophonium is an anticholinesterase muscle stimulant that facihtates myoneural junction impulse transmission by inhibiting acetylcholine destmction by cholinesterase. It is indicated in differential diagnosis of myasthenia gravis as an adjunct in evaluating treatment of myasthenia gravis in evaluation of aner-gency treatment of myasthenic aises in reversal of neuromuscular blockade by curare gallamine or tubo-curarine and in treatment of respiratory depression caused by curare overdose. 

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