Name: Neostigmine (Prostigmine)
Class: Anticholinesterase Agent: Carbamate (Quaternary Amine)
Mech.: Substrate for AChE. Competitive inhib. of interaction btwn ACh and AChE. Stim. postjxnl nicotinic (i.e., muscular) receptors.
Absorption: Oral adequate.
Dist.: No CNS. Acts mostly at neuromusc sites. Some autonomic action.
Metab.: Slowly hydrolyzed by AChE
Excretion, t½: Slowly hydrolyzed by AChE
Toxicity/S.E.s: Toxic doses first stim. then depress autonomic ganglia, neuromusc. jxns, and central sites. Dose too large ® skeletal muscle weakness = cholinergic crisis. Dose too small ® skeletal muscle weakness = myasthenic weakness. Avoid in cases of asthma, coronary insufficiency, peptic ulcers.
Utility: Treat myasthenia gravis. Treat post-op paralytic ileus and urinary bladder atony. Antag. NM blockade of curare-like agents.
Special Features: IV ® Non-selective. Stim. cholinergic receptors throughout CNS and PNS. Inhib. AChE and BuChE. Musc. effects prevented by pretreatment w/atropine.