Pirenzepine (Gastrozepin), an
M1 selective antagonist, is used in the treatment of
peptic ulcers, as it reduces
gastric acid
Gastric acid, gastric juice, or stomach acid is a digestive fluid formed within the stomach lining. With a pH between 1 and 3, gastric acid plays a key role in digestion of proteins by activating digestive enzymes, which together break down the ...
secretion and reduces
muscle spasm. It is in a class of drugs known as
muscarinic receptor antagonists
A muscarinic receptor antagonist (MRA) is a type of anticholinergic agent that blocks the activity of the muscarinic acetylcholine receptor. The muscarinic receptor is a protein involved in the transmission of signals through certain parts of the ...
-
acetylcholine
Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Part ...
being the neurotransmitter of the
parasympathetic nervous system
The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of ...
which initiates the rest-and-digest state (as opposed to fight-or-flight), resulting in an increase in gastric motility and digestion; whereas pirenzepine would inhibit these actions and cause decreased gastric motility leading to delayed gastric emptying and constipation.
It has no effects on the brain and spinal cord as it cannot diffuse through the
blood–brain barrier
The blood–brain barrier (BBB) is a highly selective semipermeable membrane, semipermeable border of endothelium, endothelial cells that prevents solutes in the circulating blood from ''non-selectively'' crossing into the extracellular fluid of ...
.
Pirenzepine has been investigated for use in
myopia
Near-sightedness, also known as myopia and short-sightedness, is an eye disease where light focuses in front of, instead of on, the retina. As a result, distant objects appear blurry while close objects appear normal. Other symptoms may include ...
control.
It promotes the homodimerization or
oligomerisation of
M1 receptors.
See also
*
AFDX-384
*
Telenzepine
References
Muscarinic antagonists
Piperazines
Lactams
Pyridobenzodiazepines
Acetamides
Peripherally selective drugs
{{gastrointestinal-drug-stub