Tiotropium (Spiriva) is a long acting anticholinergic bronchodilator licensed for use in Chronic Obstructive Pulmonary Disease (COPD). It has been shown to maintain FEV1 in patients with COPD, but how does this equate to patient outcomes like exacerbations and hospital admissions?
A recent study in the Annals of Internal Medicine investigated the impact that tiotropium had on COPD exacerbation and hospital admission compared to placebo over a period of 6 months. The study has also been reported as an InfoPOEM in the Pharmaceutical Journal.
The study was conducted in 26 Veterans Affairs medical center so 99% of the patients were male. Patients had moderate to severe COPD with a mean baseline FEV1 of 36%. Patients received usual care, excluding use of other anticholinergic bronchodilators (ipratropium).
The study found that there was a statistically significant decrease in the number of exacerbations, but the actual difference was slight. The NNT was 23 to prevent on exacerbation in 6 months, but the confidence intervals extend to between 12 and 456. The impact on hospital admissions did not reach statistical significance although there were fewer admissions for COPD in the tiotropium arm. There was no impact on all-cause hospital admission.
The responses to this study point out that usual care in general practice would involve ipratropium and they are therefore critical of the design of the study. Knowing this exclusion however, allows the study to be put into context. The benefits of tiotropium in this study appear to be clinically marginal. As practice in primary care would not exclude the use of ipratropium this may have the effect of diluting the effect further.
Tiotropium treatment does decrease COPD exacerbations over 6 months but it does not decrease hospital admissions. Using the NNT of 23 this would equate to treating one patient for 11 years to prevent one exacerbation.
Action: The NICE COPD Guideline recommends that long acting bronchodilators are used in patients who remain symptomatic on short-acting agents. This study backs this advice.