tiotropium-bromide and Bronchial-Hyperreactivity

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.

Topics: Administration, Inhalation; Adult; Analysis of Variance; Asthma; Bronchial Hyperreactivity; Bronchial Provocation Tests; Cholinergic Antagonists; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Forced Expiratory Volume; Humans; Ipratropium; Male; Methacholine Chloride; Premedication; Probability; Reference Values; Respiratory Function Tests; Scopolamine Derivatives; Sensitivity and Specificity; Severity of Illness Index; Tiotropium Bromide; Treatment Outcome

Tiotropium is a long acting muscarinic antagonist (LAMA), licensed as triple therapy with inhaled corticosteroid and long-acting beta-agonist (ICS/LABA). There may be a synergistic benefit between LAMA and LABA as a consequence of receptor cross-talk, which in turn could modify beta-2 receptor downregulation and associated tolerance induced by LABA.. We hypothesize this mechanism may result in a reduction of airway hyperresponsiveness (AHR) when using triple therapy.. We evaluated 14 non-smoking asthmatics using an open-label, randomized crossover design. ICS with Indacaterol and Tiotropium (IND/TIO) vs ICS with Indacaterol (IND) over 4 weeks with challenge performed after first and last doses at trough.. Our data suggest that concomitant tiotropium does not modify the bronchoprotective tolerance induced by Indacaterol, in turn suggesting that cross-talk may not be clinically relevant when using triple therapy. This study was registered on clinicaltrials.gov as NCT02039011.

Topics: Adult; Aged; Asthma; Biomarkers; Bronchial Hyperreactivity; Drug Therapy, Combination; Female; Humans; Indans; Male; Middle Aged; Muscarinic Antagonists; Quinolones; Respiratory Function Tests; Tiotropium Bromide; Treatment Outcome

Asthma is characterized by reversible bronchoconstriction and airway hyperreactivity. Although M(3) muscarinic receptors mediate bronchoconstriction, non-selective muscarinic receptor antagonists are not currently recommended for chronic control of asthma. We tested whether selective blockade of M(3) receptors, at the time of antigen challenge, blocks subsequent development of airway hyperreactivity in antigen-challenged guinea-pigs.. Ovalbumin-sensitized guinea-pigs were pretreated with 1 µg·kg(-1) of a kinetically selective M(3) receptor antagonist, tiotropium, or 1 mg·kg(-1) of a non-selective muscarinic receptor antagonist, atropine, and challenged with inhaled ovalbumin. Animals were anaesthetized, paralyzed, ventilated and vagotomized 24 h later. We measured vagally mediated bronchoconstriction and i.v. ACh-induced bronchoconstriction.. Electrical stimulation of both vagus nerves induced frequency-dependent bronchoconstriction in sensitized animals that was significantly increased after antigen challenge. Antigen-induced hyperreactivity was completely blocked by tiotropium pretreatment but only partially blocked by atropine pretreatment. Surprisingly, although tiotropium blocked bronchoconstriction induced by i.v. ACh, it did not inhibit vagally-induced bronchoconstriction in sensitized controls, suggesting that tiotropium does not block hyperreactivity by blocking receptors for vagally released ACh. Rather, tiotropium may have worked through an anti-inflammatory mechanism, since it inhibited eosinophil accumulation in the lungs and around nerves.. These data confirm that testing M(3) receptor blockade with exogenous ACh does not predict vagal blockade. Our data also suggest that selective blockade of M(3) receptors may be effective in asthma via mechanisms that are separate from inhibition of bronchoconstriction.

Topics: Acetylcholine; Animals; Asthma; Atropine; Bronchial Hyperreactivity; Bronchoconstriction; Disease Models, Animal; Eosinophils; Female; Guinea Pigs; Inflammation; Ovalbumin; Receptor, Muscarinic M3; Scopolamine Derivatives; Tiotropium Bromide; Vagus Nerve