<prompt> Why pyridostigmine is preferred in myasthenia gravis?It doesnt cross BBBLonger acting than neostigmineIt crosses BBBSho-acting than neostigmine  <response>: DOC FOR myasthenia gravis is pyridostigmine as it long acting than neostigmine.both are quaternanry coumpounds and so cant cross BBB Ref: KDT 6th ed pg 101-102 