Antimuscarinics (Respiratory)

Antimuscarinics with predominantly cardiac effects are covered at Antimuscarinics (Cardiac), whilst atropine is covered separately.

These agents competitively antagonise ACh at M3 receptors in bronchial smooth muscle, preventing parasympathetic mediated bronchoconstriction.

Property Ipratropium Tiotropium
Class Muscarinic antagonist Muscarinic antagonist
Uses Bronchodilatation Bronchodilatation
Presentation MDI or solution for nebulisation MDI
Route of Administration Inhaled Inhaled
Dosing 18mcg MDI, 500µg nebuliser
Absorption 5% bioavailability via inhaled route
Metabolism Hepatic to inactive metabolites
Elimination Equal renal and faecal elimination
Resp Bronchodilation Bronchodilation
GIT Decreased GI secretions in large doses Decreased GI secretions in large doses
CNS Mydriasis if deposited in eye Mydriasis if deposited in eye

References

  1. Peck TE, Hill SA. Pharmacology for Anaesthesia and Intensive Care. 4th Ed. Cambridge University Press. 2014.
  2. Smith S, Scarth E, Sasada M. Drugs in Anaesthesia and Intensive Care. 4th Ed. Oxford University Press. 2011.
Last updated 2017-08-03

results matching ""

    No results matching ""