Pyridostigmine Bromide

Pyridostigmine bromide is a parasympathomimetic and a reversible cholinesterase inhibitor.Target: AChEPyridostigmine bromide is a parasympathomimetic and a reversible cholinesterase inhibitor. Since it is a quaternary amine, it is poorly absorbed in the gut and does not cross the blood–brain barrier, except possibly in stressful conditions. Pyridostigmine bromide inhibits acetylcholinesterase in the synaptic cleft, thus slowing down the hydrolysis of acetylcholine. It is a quaternary carbamate inhibitor of cholinesterase that does not cross the blood–brain barrier which carbamylates about 30% of peripheral cholinesterase enzyme. The carbamylated enzyme eventually regenerates by natural hydrolysis and excess ACh levels revert to normal.Pyridostigmine bromide is used to treat muscle weakness in people with myasthenia gravis and to combat the effects of curariform drug toxicity. Pyridostigmine bromide has been FDA approved for military use during combat situations as an agent to be given prior to exposure to the nerve agent Soman in order to increase survival. Used in particular during the first Gulf War, pyridostigmine bromide has been implicated as a causal factor in Gulf War syndrome. Pyridostigmine bromide sometimes is used to treat orthostatic hypotension. It may also be of benefit in chronic axonal polyneuropathy.

References:
[1]. Gales BJ, et al. Pyridostigmine in the treatment of orthostatic intolerance. Ann Pharmacother. 2007 Feb;41(2):314-8. Epub 2007 Feb 6.
[2]. Kanjwal K, et al. Pyridostigmine in the treatment of postural orthostatic tachycardia: a single-center experience. Pacing Clin Electrophysiol. 2011 Jun;34(6):750-5.