A muscarinic antagonist used to study binding characteristics of muscarinic cholinergic receptors. [PubChem]
Indication
Used as adjunctive therapy for the treatment of peptic ulcer. Also used to treat nausea and vomiting due to motion sickness.
Pharmacology
Methscopolamine is a muscarinic antagonist structurally similar to the neurotransmitter acetylcholine and acts by blocking the muscarinic acetylcholine receptors and is thus classified as an anticholinergic. Methscopolamine has many uses including the prevention of motion sickness. It is not clear how Methscopolamine prevents nausea and vomiting due to motion sickness. The vestibular part of the ear is very important for balance. When a person becomes disoriented due to motion, the vestibule sends a signal through nerves to the vomiting center in the brain, and vomiting occurs. Acetylcholine is a chemical that nerves use to transmit messages to each other. It is believe that Methscopolamine prevents communication between the nerves of the vestibule and the vomiting center in the brain by blocking the action of acetylcholine. Methscopolamine also may work directly on the vomiting center. Methscopolamine must be taken before the onset of motion sickness to be effective.
Toxicity
Symptoms of a methscopolamine overdose include headache, nausea, vomiting, dry mouth, difficulty swallowing, blurred vision, dilated pupils, hot, dry skin, dizziness; drowsiness, confusion, anxiety, seizures, weak pulse, and an irregular heartbeat. In addition, a curare-like action may occur, i.e., neuromuscular blockade leading to muscular weakness and possible paralysis.
Affected Organisms
Humans and other mammals
Biotransformation
Little is known about the fate and excretion of methscopolamine.
Absorption
Poorly and unreliably absorbed, total absorption is 10-25%.
