ipratropium bromide + metabisulfite

**Ipratropium bromide + metabisulfite** denotes an inhaled ipratropium bromide preparation in which metabisulfite is treated as a non-active preservative/excipient rather than a second therapeutic drug. Ipratropium bromide is a short-acting antimuscarinic bronchodilator that reduces vagally mediated bronchoconstriction by competitively blocking acetylcholine at airway muscarinic receptors, principally the M3 receptor on bronchial smooth muscle. In the supplied asthma-provocation publication, ipratropium was administered before inhaled metabisulfite challenge to assess the cholinergic contribution to metabisulfite-induced bronchoconstriction; that study does not establish a distinct marketed fixed-dose ipratropium-metabisulfite product. ([europepmc.org](https://europepmc.org/articles/PMC1381378))

Other names

ipratropium bromide + MBSipratropium bromide + metabisulfiteipratropium bromide + metabisulphite