why neostigmine is not given in succinylcholine poisoning?

Answer:
Previous answer is a bit off.Neostigmine is an anti-acetylcholinesterase. It blocks the enzyme that breaks down acetylcholine in the body. As the acetylcholine builds up, it can displace the muscle relaxant at the motor end plate and the person can once again move. All of the various muscle relaxants are metabolized by the body, with or without the introduction of neostigmine as a reversal agent. In general, Succ wears off so fast it does not need reversal. In fact the half life of the neostigmine is considerably greater than the Succ. Since neostigmine is a weak "nerve agent" and can cause paralysis itself the view is, if you do not need it, do not give it. There are people out there who can not break down Succ, so the proper treatment is to give fresh frozen plasma which contains the enzyme needed to break it down. (If you give neostigmine you might see a very temporary improvement but if you do not get the Succ metabolized, when the neo wears off, you will be right back where you started.) There is only one instance where neostigmine is indicated after the use of Succ. As Succ gets broken down, one of the products of the break down is succ MONO choline. That is a very weak non-depolarizer muscle relaxant. In cases where a person got a lot of Succ, such as in the "olden days" when a constant drip of Succ was used, or when the anesthesia provider gives repeated doses, the build up of succ MONO choline could cause prolonged paralysis. And for THAT you could use neostigmine, but the provider had better make sure he is correct in his assessment.

---

succinylcholine is a depolarising muscle relaxant and neostigmine is a cholinergic that act against non depolarising agent like atracorium .
we have cholinestrase enzyme inour body that act against succinyl choline

---