Abstract
The technique for intravenous administration of Tensilon (edrophonium chloride) varies. In 1952, Osserman and Genkins1introduced the test and recommended a 2-mg initial dose followed, if no reaction (usually cholinergic) occurred in 45 s, by the rapid administration of an additional 8 mg. Others have modified the test by waiting five minutes after the initial dose,2by injecting Tensilon in small increments after the initial dose,2-6or by slowly infusing the remaining 8 mg.5Although I have recently been converted by Norman Schatz, MD, to the small-increment method, the significant controversy this essay should address is not drug administration but rather the testend point. What constitutes a "positive" Tensilon response in the physician's office where (without benefit of oculographic equipment7-10) the first Tensilon test is performed in a suspected myasthenic? Such a determination is obviously important since a positive test is virtually diagnostic of