COMPARISON OF THE BRONCHODILATOR EFFICACY OF NEBULIZED PIRENZEPINE AND IPRATOPIUM BROMIDE IN PATIENTS WITH AIRWAY OBSTRUCTIVE LUNG-DISEASE

Ipratropium bromide (IB) is a non-selective muscarinic antagonist, who se bronchodilator efficacy has been shown in reversible and irreversib le obstructive airway diseases. Pirenzepine is a M1 receptor antagonis t and effective in vagally-induced bronchoconstriction. To investigate the bronchodilator efficacy of nebulized pirenzepine, we compared neb ulized pirenzepine with nebulized IB and nebulized isotonic saline (pl acebo). Eighteen patients with reversible and 18 patients with irrever sible obstructive airway disease were studied. Nebulized isotonic sali ne (placebo), 100 mcg nebulized pirenzepine and 125 mcg nebulized IB w ere given on three consecutive days. Spirometry was performed prior to nebulization and repeated at 5, 30, 60, 90 and 120 minutes following nebulized medication. A dose of 125 mcg IB resulted in a significant i ncrease in FEV1 in patients with both reversible or irreversible bronc hoconstriction (p <0.00001, p <0.03). IB at the same dose resulted in an increase in FVC in patients with irreversible bronchoconstriction ( p <0.001) and an increase in FEF25-75 in patients with reversible bron choconstriction (p <0.0003). Pirenzepine therapy resulted in no signif icant change in the same parameters. It is concluded that nebulized pi renzepine at a dose of 100 mcg does not have bronchodilator effect in patients with reversible or irreversible bronchoconstriction.