The effect of ipratropium nasal spray on bronchial methacholine challenge

Methacholine challenge testing: comparative pharmacology

Standardization of the methacholine inhalation challenge, the most common direct bronchoprovocation test, is important. One aspect of standardization is the appropriate washout period for pharmacologic agents which affect the response. This review summarizes the available data on pharmacologic inhibition of the methacholine response. Specific (anti-muscarinic) agents demonstrate marked bronchoprotection (up to 7 days for the long-acting drugs) which lasts longer than the duration of bronchodilation. The functional antagonist (beta 2 agonist class of medications) shows marked, but less, bronchoprotection which is relatively short lived and is similar to the duration of bronchodilator efficacy. Tolerance develops quickly, especially to the long-acting agents. Single doses of controller medications, such as inhaled corticosteroids (ICS) and leukotriene receptor antagonists, have no effect on the methacholine test, while regular use, at least for ICS, has a modest protective effect whose duration is uncertain and likely variable. Theophylline has a small effect and H1 blockers (all generations) have a negligible effect.

Comparison of the protective effect amongst anticholinergic drugs on methacholine-induced bronchoconstriction in asthma

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.

Same efficacies of ipratropium and salbutamol in reversing methacholine-induced bronchoconstriction

Efficacy of salbutamol (S) was compared to that of ipratropium (I) or to their association, after methacholine challenge testing (MCT). MCT was performed in 4 groups of 10 patients suspected to suffer from asthma; mean changes in FEV1, maximal midexpiratory flow rate (MMFR), and airway resistance (Raw) were the same in all groups. After MCT, the group 1 patients inhaled S and then I, 10 min later; both drugs were given in the reverse order to the group 2 patients. The group 3 patients inhaled a mixture of both drugs just after MCT; the group 4 patients were not given any bronchodilator till the 20th min after MCT, when they inhaled S. Short-term (10 min) bronchodilator effects of S, I or S + I on spirometric variables were of the same magnitude and Raw returned to its baseline value. Further improvement (10-20 min) in FEV1 was mainly due to spontaneous recovery, whereas further increase in MMFR was due also to bronchodilator actions of drugs. It is concluded that ipratropium could be proposed as an alternative bronchodilator to salbutamol after MCT.