Zanamivir, a new targeted therapy in the treatment of influenza - A patient perspective assessed by questionnaire

Objective: A patient survey was conducted by questionnaire to evaluate patient acceptance and perceptions of efficacy with zanamivir (Glaxo Wellcome), the first in a new class of neuraminidase inhibitors that are active against both influenza A and influenza B. The survey was also designed to provide rapid feedback to physicians prescribing zanamivir within the winter period when influenza was likely to be prevalent. Setting: Patients with clinically diagnosed influenza were enrolled by participating general practitioners (GPs) during the 1999 influenza season in Australia. Courses of medication with a questionnaire were prescribed by participating GPs. Patients: A total of 1408 patients returned completed questionnaires, 60% were employed or were students and 238 had had a current influenza immunisation, mostly patients >65 years. Myalgia, headache and feverishness were reported by at least 80% of patients. Results: Symptom relief was reported by more than 50% of patients within 24 hours and by 77% of patients within 48 hours; satisfaction with treatment was high and 65% of patients returned to normal activities within 72 hours. Older patients reported a slightly less rapid response to zanamavir in terms of symptom relief, but nevertheless were able to return quickly to normal activities. A total of 378/477 (79%) patients who were very satisfied with their treatment experienced symptom relief in 24 hours. Of the 400 at-risk patients aged >65 years or with co-morbidities, 78% were satisfied with their treatment, with 235/400 (59%) experiencing symptom relief within 24 hours. Patients found the Diskhaler(TM) device easy to use irrespective of age and reported rapid symptom relief, which may reflect the targeted delivery of high concentrations of zanamivir to the site of viral replication in the respiratory tract. Conclusion: Overall, the survey indicated that zanamivir was associated with an early return to normal activities and confirmed that the benefits observed with the drug in controlled clinical trials were extrapolated to community practice.