Comparison of elderly people's technique in using two dry powder inhalers to deliver zanamivir: randomised controlled trial.

OBJECTIVE To determine whether elderly people can learn to use the inhaler used to deliver zanamivir (Relenza Diskhaler) as effectively as the Turbohaler and to identify which aspects of inhaler technique are most problematic. DESIGN Randomised, controlled, intervention study. SETTING Wards for acute elderly care in a large district general hospital. PARTICIPANTS 73 patients who were unfamiliar with the use of an inhaler, aged 71 to 99 (mean 83) years. MAIN OUTCOME MEASURES Initial scores and changes in scores 24 hours later using a 10 point scoring system of five aspects of inhaler technique. RESULTS 38 patients were allocated the Relenza Diskhaler and 35 the Turbohaler. The mean total score was significantly greater in the Turbohaler than Diskhaler groups both initially (8.74 v 7.05) and after 24 hours (8.28 v 5.43). The major difference between inhalers was in loading and priming. After tuition 50% (19 of 38) of patients allocated the Diskhaler were unable to load and prime the device and 65% (24 of 37) were unable to do so 24 hours later. Of those allocated the Turbohaler, two patients were unable to load and prime the device after initial review and one after 24 hours. CONCLUSION Most elderly people cannot use the inhaler device used to deliver the anti-influenza drug zanamivir. Treatment with this drug is unlikely to be effective in elderly people unless the delivery system is improved.