Q: Pyridostigmine (Mastinon) which is well known for its use in Myasthenia Gravis can also be use in which other common condition?

Answer: Orthostatic hypotension 

Pyridostigmine has been studied and found to be significantly effective to treat orthostatic hypotension. Beside Midodrine, this could be another nice drug to use in those frustrating situations in ICU where orthostatic hypotension delays transfer out of ICU. Usual dose is 60 mg PO up to 3 times per day.

Reference:

Gales BJ, Gales MA. (2007). "Pyridostigmine in the treatment of orthostatic intolerance". Annals of Pharmacotherapy 41 (2): 314–8

Singer W; Sandroni P; Opfer-Gehrking TL; Suarez GA; Klein CM; Hines S; O'Brien PC; Slezak J; Low PA. "Pyridostigmine Treatment Trial in Neurogenic Orthostatic Hypotension." Archives of Neurology, April 2006, Vol. 63, No. 4, pp. 513-518 .