Acetyl Cholinesterase Inhibitors (AChE) are drugs that restrict the acetyl cholinesterase enzyme from breaking down acetyl choline. They increase the level and the duration of action of this neuro-transmitter. They can be classified as both reversible and irreversible.
What are they used to treat?
They are the basic line of treatment for myasthenia gravis (MG). Edrophonium is basically used as a diagnostic tool as a result of its shorter life. Pyridostigmine is given for longer term of maintenance. High dosage of corticosteroids is used to suppress auto-immunity. Patients with myasthenia gravis may also be prescribed Azathioprine and Cyclosporine. Bronchodilators may be helpful in taking care of the broncho-spasm that is linked with cholinergic crisis.
AChE are also used medicinally
• To treat glaucoma
• To treat postural tachycardia syndrome
• As an antidote to anti-cholinergic poisoning
• To reverse the effect of non-depolarising muscle relaxants
• To treat neuropsychiatric symptoms of diseases such as Alzheimer's disease, particularly apathy.
• Some major effects of cholinesterase inhibitors:
• Actions on the parasympathetic nervous system may cause bradycardia, hypotension, hyper-secretion, broncho-constriction, GI tract hyper-motility and decrease intraocular pressure.
• Actions on the neuromuscular junction will result in prolonged muscle contraction.
Administration of reversible cholinesterase inhibitors is contraindicated with those that have urinary retention due to obstruction.