Edrophonium test for myasthenia gravis

The "edrophonium test" is infrequently performed to identify MG; its application is limited to those situations in which other investigations have failed to yield a conclusive diagnosis. This test requires the intravenous administration of edrophonium chloride (Tensilon, Reversol) or neostigmine (Prostigmin), drugs that block the breakdown of acetylcholine by cholinesterase (acetylcholinesterase inhibitors) and temporarily increases the levels of acetylcholine at the neuromuscular junction. In people with myasthenia gravis involving the eye muscles, edrophonium chloride will briefly relieve weakness.