D. Pyridostigmine and ambenonium

Pyridostigmine and ambenonium are other cholinesterase inhibitors that are used in the chronic management of myasthenia gravis. Their durations of action are intermediate (3 to 6 hours and 4 to 8 hours, respectively), but longer than that of neostigmine. Adverse effects of these agents are similar to those of neostigmine.