Antimuscarinic drugs

Abstract

Anticholinergic, or antimuscarinic, drugs have been used for the treatment of more or less specified gastrointestinal diseases or complaints for many centuries, first in herbal preparations (including belladonna), and in modern times as synthetic tertiary or quaternary compounds, with atropine being a pharmacological standard. Conventional antimuscarinics act unselectively on receptors in heart, smooth muscle and exocrine glands. The M1-selective antimuscarinic drugs, pirenzepine and telenzepine, moderately reduced gastric acid and pepsin secretion without inhibiting smooth-muscle activity as do non-selective antimuscarinics. They hasten peptic ulcer healing and improve the symptoms of reflux esophagitis. In combination with H2-antagonists they abolish gastric acid secretion almost completely and can, therefore, be used in high risk peptic conditions. Long-term trials have to show whether they can form a medical alternative to parietal cell vagotomy. The effect of M1-selective antimuscarinics on "non-ulcer dyspepsia" is still equivocal, but they may be useful in the treatment of disorders with increased intestinal spasticity.