Related Experiment Video
Updated: Jul 4, 2026
Assessment of Respiratory Function in Conscious Mice by Double-chamber Plethysmography
Published on: July 10, 2018
Comparison of the protective effect amongst anticholinergic drugs on methacholine-induced bronchoconstriction in
Bruno Sposato1, Sposato Bruno, Roberta Barzan
1UOC Pneumologia, Azienda Ospedaliera "Misericordia", Grosseto, Italy.
Abstract:
The protective effect of inhaled anticholinergic drugs in the methacholine-induced bronchospasm is well-known. The objective of this study was to assess if any possible differences may be found among Ipratropium (IB), Oxitropium (OXI) and Tiotropium (TIO) pre-treatments to obtain the protective effect. Forty-four patients with intermittent bronchial asthma and PD(20)FEV(1) < 200 microg were selected (24 M, 20 F; mean age 32 +/- 8.8). On the baseline, they had mean FEV(1)%: 98.8 +/- 8.54 of theoretical and mean PD(15)FEV(1) 111.8 +/- 61.04 microg. After 72 hours, all patients underwent a second methacholine challenge and were given Ipratropium (40 microg by MDI in 14 pts) or Oxitropium (200 microg by MDI in 14 pts) or Tiotropium (18 microg by Handihaler in 16 pts) sixty minutes before the test. Sixty minutes after the bronchodilator inhalation, the FEV(1)% increase was higher (p < 0.05) in OXI (6.7 +/- 4.83%) and TIO groups (6.11 +/- 2.54%) than in the IB group (3.8 +/- 1.96%). In the IB group PD(15)FEV(1) and PD(20)FEV(1) were obtained in all patients, while in the OXI group they were obtained in 12 and 5 pts respectively and in the TIO group in 14 and 5 pts respectively. Normal hyperreactivity was obtained in 2 patients, in both OXI and TIO groups. In OXI and TIO, the PD(15) obtained after drug pre-medication, was similar (respectively 1628 +/- 955.7 and 1595.5 +/- 990 microg), but higher (p < 0.0001) in comparison to the PD(15) measured in the IB group (532.2 +/- 434.8 microg). Also, the dose-response slope (decline percentage of FEV(1)/cumulative methacholine dose) after PD(15) was similar in both OXI and TIO groups but different in the IB group. A significant relationship (p < 0.01) was found between PD(15)FEV(1) (obtained in 40 pts) and the increase in FEV(1)% obtained 60 minutes after bronchodilator inhalations (r = 0.53). In conclusion, with a standard dose, both Oxitropium and Tiotropium seem to have the same protective effect in bronchial asthma but higher than Ipratropium. It's probable that the best dose of Ipratropium should be a higher one than the usual dose taken.
Related Concept Videos
01:20Antiasthma Drugs: Muscarinic Receptor Antagonists
Antimuscarinic agents compete with ACh for the same binding site on the muscarinic receptors. By binding to these receptors, they inhibit the downstream effects of ACh and block the parasympathetic...
01:24Antiasthma Drugs: Methylxanthines
Theophylline is thought to inhibit phosphodiesterase enzymes, increasing intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). This rise in cAMP and cGMP concentrations stimulates cardiac function,...
01:25Antiasthma Drugs: β2-Adrenoceptor Agonists
One class of bronchodilators includes β2-adrenoceptor agonists. These agents target the β2-adrenoceptors located on bronchial smooth muscle cells. By stimulating these receptors, β2-agonists induce relaxation in these...
01:11Direct-Acting Cholinergic Agonists: Therapeutic Uses
01:28Cholinergic Antagonists: Pharmacological Actions
Gastrointestinal Effects: Antimuscarinics reduce gut contractions, increase gastric emptying, and slow intestinal transit. They partly inhibit gastric acid secretion...
01:25Antiasthma Drugs: Mast Cell Stabilizers and Anti-IgE Drugs
Mast cell stabilizers, such as cromolyn (also known as sodium cromoglycate) and nedocromil (Tilade), are effective drugs in asthma management. These stabilizers hinder histamine release by skillfully obstructing the activation of mast cells and other cellular entities. Notably, they navigate this task without...