View source for Template:Myasthenic vs cholinergic crisis

===[[Myasthenia gravis|Myasthenic]] versus [[cholinergic crisis]]===
''Flaccid paralysis resulting from cholinergic crisis can be distinguished from [[myasthenia gravis]] by the use of the drug [[edrophonium]], which worsens the paralysis caused by cholinergic crisis, but strengthens the muscle in the case of myasthenia gravis. (Edrophonium is an cholinesterase inhibitor hence increases the concentration of acetylcholine present).''
*Myasthenic Crisis
**Respiratory failure is feared complication
**Much more common
**Due to medication non-adherence, infection, surgery, tapering of immunosuppressants, meds
*Cholinergic Crisis
**Excessive anticholinesterase medication may cause weakness and cholinergic symptoms
**Rarely if ever seen with dose limitation of pyridostigmine to less than 120mg q3hr
**If on usual dose of meds assume exacerbation due to MG even with cholinergic side effects
*[[Edrophonium]] (Tensilon) test to distinguish the two is controversial
**Give 1-2mg IV slow push. If any fasciculations, respiratory depression, or cholinergic symptoms within a few minutes, problem is likely cholinergic crisis (no more edrophonium). If no evidence of cholinergic excess, give total of 10mg and observe improvement in case of myasthenic crisis.
**Side effects of Edrophonium: Arrhythmias, Hypotension, Bronchospasm
**Thus, need to be on a monitor, with atropine on hand
**Treatment: Atropine