Comparison of nebulized and intravenous terbutaline during exacerbations of pulmonary infection in patients with cystic fibrosis.
Twenty three patients completed a double-blind study, comparing intravenous and nebulized terbutaline, during the first four days of a pulmonary exacerbation of cystic fibrosis (CF), with follow-up to day 10. Routine treatment with chest physiotherapy and appropriate intravenous antibiotics was given to all patients. The best peak flow rate (PF), forced expiratory volume in one second (FEV1) and forced vital capacity (FVC), in the past year and at entry to the study, revealed no significant difference between the groups. However, on day 10, PF, FEV1 and FVC, of the nebulizer group remained significantly reduced compared to best values in the previous year, whereas the PF and FEV1 in the intravenous group were not significantly reduced compared to the best values in the previous year. Comparison of regression lines showing the overall rate of improvement of PF, FEV1 and FVC between the two groups showed that the rate of improvement of each parameter was more rapid in the group receiving intravenous terbutaline. This was statistically significant for PF. It is possible that during acute exacerbations of infection, sputum retention makes it more difficult for the inhaled bronchodilators to reach the airways and intravenous therapy is, therefore, more beneficial.