- close structural analogue of atropine; but has an added ethyl group to the nitrogen so is a quaternary amine with a +Ve charge (can't cross bio membranes - key to keeping ipratropiums effects to the lungs, and not allowing it into the circulation) - is a non-selective mAChR antagonist that is benefical in asthma, usuall in combination with other drugs. - given by an MDI - reduces irritant pathways (involve cholinergic neurons) - reduces bronchoconstriction, mucus secretion and cough