Neostigmine, sold under the brand name Prostigmin among others, is a medication used to treat myasthenia gravis, Ogilvie syndrome, and urinary retention without the presence of a blockage.[1][2] It is also used together with atropine to end the effects of neuromuscular blocking medication of the non-depolarizing type.[1] It is given by injection either into a vein, muscle, or under the skin.[1] After injection effects are generally greatest within 30 minutes and last up to 4 hours.[1]