Pyridostigmine is a cholinesterase inhibitor used for the treatment of myasthenia gravis. It is usually administered intravenously and is very similar to neostigmine but with a less adverse effect profile and longer duration of action. The autoimmune disease known as myasthenia gravis is characterized defect of acetylcholine interacting at the neuromuscular junction. This results in muscle weakness, muscle loss and overall fatigue. Pyridostigmine inhibits the breakdown of acetylcholine allowing for an increase in activation and relieving the aforementioned symptoms. It specifically targets and inhibits acetylcholinesterase and cholinesterase, this increases extracellular levels of acetylcholine. Pyridostigmine is administered orally or intravenously, the latter having a better bioavailability. It is hydrolyzed in the blood by cholinesterases and in the liver by microsomal enzymes in the liver. Its main metabolite is 3-hydroxy-N-methyl-pyridinium and eliminated through the urine.

Pyridostigmine Pathway References