Tensilon test; edrophonium test

Indications

a positive test, i.e. a positive neuromuscular response to edrophonium (i.e. reversal of ptosis) is consistent a diagnosis of myasthenia gravis

discontinue all anticholinesterase medications at least 8 hours prior to administration of edrophonium
draw 10 mg of edrophonium into a syringe
2 mg test IV over 15-30 seconds
- if a cholinergic reaction occurs, stop infusion
- administer 0.5 mg of atropine IV
8 mg IV after 45 sec if no response to test dose
test may be repeated after 30 minutes