The influence of ipratropium bromide in the recovery phase of methacholine induced-bronchospasm.
BACKGROUND
The protective effect of Ipratropium Bromide (IB) in the methacholine-induced bronchospasm is well known from some time. The objective of the present study was to assess whether a pretreatment with IB may influence the subsequent phase of methacholine-induced bronchospasm relief.


METHODS
Sixteen patients with bronchial hyper-reactivity (PD20 FEV1 < 200 microg) were randomly assigned to three methacholine challenge tests at a 48 to 72 hours interval apart. In the first test IB was inhaled before the challenge (pre-IB), in the second IB was administered soon after the PD20 FEV1 (post-IB), and in the third no treatment was given (control).


RESULTS
The pre-IB PD20 FEV1 (695 +/- 587.6 microg) was significantly greater (p < 0.0001) than that of post-IB (82.2 +/- 49.18 microg) and of control (73.9 +/- 41.8 microg). The dose response slope (DRS) (decline percentage of FEV1/cumulative methacholine dose), in pre-IB was greatly lower (p < 0.0001) than that in post-IB and in control. During the bronchospasm relief phase, the increase of FEV1 measured after 5, 10, 15, 30 and 60 minutes from the PD20 FEV1 was significantly greater in post-IB (p < 0.05) compared with the other two conditions. Conversely, the recovery slope (RS) (increase percentage of FEV1 at 60 minutes after PD20 FEV1 x cumulative methacholine dose) was significantly more efficient (p < 0.001) in pre-IB than in post-IB and in control.


CONCLUSIONS
In conclusion, ipratropium bromide confirmed to have a good protective activity against methacholine-induced bronchospasm; the pre-administration of ipratropium bromide showed also a positive effect on the recovery phase.
Sposato
B
B
Dipartimento di Scienze Cardiovascolari e Respiratorie, Università La Sapienza, Rome, Italy. bsposat@tin.it
Mariotta
S
S
Ricci
A
A
Bruno
P
P
Terzano
C
C
Mannino
F
F
D000280:Administration, Inhalation; D000328:Adult; D001249:Asthma / Q000150:complications*; D016535:Bronchial Hyperreactivity / Q000150:complications*; D001985:Bronchial Provocation Tests; D001986:Bronchial Spasm / Q000209:etiology / Q000517:prevention & control*; D016085:Bronchoconstrictor Agents / Q000008:administration & dosage; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D009241:Ipratropium / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D016210:Methacholine Chloride / Q000008:administration & dosage; D020127:Recovery of Function
D016085:Bronchoconstrictor Agents; D001993:Bronchodilator Agents; D016210:Methacholine Chloride; D009241:Ipratropium