edrophonium test

edrophonium test

a test for myasthenia gravis in which an IV solution of edrophonium chloride is injected into a patient. A total of 10 mg of the cholinergic drug is prepared, and a 2-mg dose is injected. If there is no reaction in 30 seconds, the remaining 8 mg is administered. A brief improvement in muscle activity is regarded as a positive result. Edrophonium chloride is also used to distinguish between myasthenia gravis and a cholinergic crisis. Because edrophonium chloride can precipitate respiratory depression, the test should not be performed unless an anticholinergic antidote, such as atropine, and respiratory resuscitation equipment are available. For further explanation of electroencephalographic recording of brain waves. See also alpha wave, beta wave, delta wave, theta wave.

edrophonium test

The use of edrophonium chloride to test for the presence of myasthenia gravis. The appropriate dose is injected intravenously; if there is no effect, a larger dose is given within 45 sec. A positive test demonstrates brief improvement in strength unaccompanied by lingual fasciculation. The test may also be used to determine an overdose of a cholinergic drug. An excessive dose of cholinergic drug produces weakness that closely resembles myasthenia. A very small dose of edrophonium chloride given intravenously worsens the weakness if it is due to cholinergic drug overdose and improves it if it is due to myasthenia gravis.

CAUTION!

The test should not be performed unless facilities and staff for respiratory resuscitation are immediately available.
References in periodicals archive ?
Investigations performed at this time had confirmed normal electrolytes, normal renal function, normal creatine kinase levels, normal cardiac enzymes, a normal short synacthen test, normal thyroid function and a normal edrophonium test.
She was given an edrophonium test and her symptoms improved.
An edrophonium test was positive with reversal of neck weakness to 5/5 power.