Selective muscarinic antagonists as bronchodilators

Agents Actions Suppl. 1991;34:117-30.


The non-selective muscarinic antagonist ipratropium is widely used as bronchodilator. Due to its pharmacokinetic properties this drug, after inhalation, acts only locally on the airways and no unwanted anticholinergic side-effects are observed. Another approach is the use of selective muscarinic antagonists. Based on their selectivity for M3- and/or M1-receptors such drugs might show bronchospasmolytic properties without the occurrence of typical atropine-like side effects even after systemic administration. Pharmacological data of the in vivo bronchoselectivity of pirenzepine (M1-selective) and AQ-RA 721 (high affinity for M1- and M3-receptors) is presented and the use of these drugs as bronchodilators is discussed.

Publication types

  • Review

MeSH terms

  • Animals
  • Bronchodilator Agents / pharmacology*
  • Humans
  • Muscarine / antagonists & inhibitors*
  • Pirenzepine / analogs & derivatives*
  • Pirenzepine / pharmacology*
  • Receptors, Muscarinic / metabolism
  • Respiratory System / metabolism
  • Salivation / drug effects


  • Bronchodilator Agents
  • Receptors, Muscarinic
  • AQ-RA 721
  • Pirenzepine
  • Muscarine