Neostigmine

Neostigmine is a parasympathomimetic, specifically, a reversible cholinesterase inhibitor.

Neostigmine is available under several trade names such as Prostigmin and Vagostigmin.

Neostigmine was first synthesized by Aeschlimann and Reinert in 1931.

Pharmacology

By interfering with the breakdown of acetylcholine, neostigmine indirectly stimulates both nicotinic and muscarinic receptors. Unlike physostigmine, neostigmine has a quarternary nitrogen; hence, it is more polar and does not enter the CNS. its effect on skeletal muscle is greater than that of physostigmine, and it can stimulate contractility before it paralyzes. Neostigmine has short duration of action, usually thirty minutes to two hours. Neostigmine binds to the anionic site of cholinesterase. The drug blocks the active site of acetylcholinesterase so the enzyme can no longer break down the acetylcholine molecules before they reach the postsynaptic membrane receptors. This allows for the threshold to be reached so a new impulse can be triggered in the next neuron. In myasthenia gravis there are too few acetylcholine receptors so with the acetylcholinesterase blocked, acetylcholine can bind to the few receptors and trigger a muscular contraction.

Clinical uses

It is used to improve muscle tone in people with myasthenia gravis and routinely, in anesthesia at the end of an operation, to reverse the effects of non-depolarizing muscle relaxants such as rocuronium and vecuronium.

It can also be used for urinary retention resulting from general anaesthesia and to treat curariform drug toxicity.

Another indication for use is the Ogilvie syndrome which is a pseudoobstruction of the colon in critically ill patients.

Historically, it has been used as a test for early pregnancy. In a non-pregnant female whose menstrual period is delayed, administration of neostigmine can provoke menstrual bleeding. Modern tests which rely on detecting hCG in urine have rendered this application obsolete.

Neostigmine will cause slowing of the heart rate (bradycardia), for this reason it is usually given along with a parasympatholytic drug such as atropine or glycopyrrolate.

Though one of only two treatments available for myasthenia gravis this drug is no longer available to anyone using the Medicare Part D program.

Translation

The word "Neostigmine" occurs as such in the following languages: English, Hungarian, Urdu.

Translation(s) in other languages: German: Neostigmin, Spanish: Neostigmina, French: Néostigmine, Italian: Neostigmina, Japanese: ネオスチグミン, Polish: Neostygmina, Portuguese: Neostigmina, Russian: Неостигмина метилсульфат, Turkish: Neostigmin.