It may also be of benefit in chronic axonal polyneuropathy.It is also being prescribed off-label for postural tachycardia syndrome as well as complications resulting from Ehlers–Danlos syndrome. Contraindications
Pyridostigmine bromide is contraindicated in cases of mechanical intestinal or urinary obstruction and should be used with caution in patients with bronchial asthma. Side effects
Common side effects include:
Sweating
Diarrhea
Nausea
Vomiting
Abdominal cramps
Increased salivation
Tearing
Increased bronchial secretions
Constricted pupils
Facial flushing due to vasodilation
Erectile dysfunctionAdditional side effects include:
Muscle twitching
Muscle cramps and weakness

Mechanism of action
Pyridostigmine 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 acetylcholine (ACh) levels revert to normal. The ACh diffuses across the synaptic cleft and binds to receptors on the post synaptic membrane, causing an influx of sodium (Na+,) resulting in depolarization. If large enough, this depolarization results in an action potential. To prevent constant stimulation once the ACh is released, an enzyme called acetylcholinesterase is present in the endplate membrane close to the receptors on the post synaptic membrane, and quickly hydrolyses ACh. Names
Pyridostigmine bromide is available under the trade names Mestinon (Valeant Pharmaceuticals), Regonol and Gravitor (SUN Pharma). References
External links
"Pyridostigmine". Drug Information Portal. U.S. National Library of Medicine.
Certain ethnic groups are more often affected; for example, 48% of American Indians have gallstones. Of all people with stones, 1–4% have biliary colic each year. If untreated, about 20% of people with biliary colic develop acute cholecystitis. Once the gallbladder is removed outcomes are generally good. Without treatment, chronic cholecystitis may occur. The word is from Greek, cholecyst- meaning "gallbladder" and -itis meaning "inflammation". Signs and symptoms
Most people with gallstones do not have symptoms. However, when a gallstone temporarily lodges in the cystic duct, they experience biliary colic. Biliary colic is abdominal pain in the right upper quadrant or epigastric region. It is episodic, occurring after eating greasy or fatty foods, and leads to nausea and/or vomiting. People with cholecystitis most commonly have symptoms of biliary colic before developing cholecystitis. The pain becomes severe and constant in cholecystitis. Nausea is common and vomiting occurs in 75% of people with cholecystitis. In addition to abdominal pain, right shoulder pain can be present.On physical examination, an inflamed gallbladder is almost always tender to the touch and palpable (~25-50% of cases) in the midclavicular right lower rib margin. Additionally, a fever is common. A gallbladder with cholecystitis is almost always tender to touch. Because of the inflammation, its size can be felt from the outside of the body in 25–50% of people with cholecystitis. Pain with deep inspiration leading to termination of the breath while pressing on the right upper quadrant of the abdomen usually causes severe pain (Murphys sign).