Post-market outcome of an extract of traditional Cretan herbs on upper respiratory tract infections: a pragmatic, prospective observational study

BACKGROUND The beneficial effects of traditional herbs of Crete, Greece for the treatment of upper respiratory tract infections have been reported in observational and laboratory studies. Following a published, double blind, randomized, placebo controlled trial, this study aimed to assess the effectiveness of an extract of three Cretan herbs on the treatment of upper respiratory tract infections, upon its market release. METHODS An observational study was conducted in Heraklion, Crete, Greece. Participants were patients presenting at selected pharmacies with symptoms of upper respiratory tract infection, choosing to receive the extract for their treatment. Patients' symptoms (local, general, total) where recorded at three time points within 1 week, using a questionnaire developed based on the Wisconsin Upper Respiratory System Survey. For each patient, symptoms were scored on a 0-7 Likert scale and three indexes were calculated: the score of local symptoms, the score of general symptoms and the total score of symptoms. Effectiveness was assessed by examining the reduction in these indexes over the 1-week observation period. RESULTS Mean score of general symptoms was 19.1 (SE: 0.9) in day 1, dropping to 8.6 (SE: 0.6) and 3.1 (SE: 0.4) in days 4 and 7 respectively. Mean score of local symptoms declined from 7.9 (SE: 0.5) in day 1 to 2.3 (SE: 0.3) in day 4 and to 0.5 (SE: 0.1) in day 7. Total score of symptoms reached 27.0 (SE: 1.2) in day 1, decreasing to 10.9 (SE: 0.8) in day 4 and to 3.5 (SE: 0.5) in day 7. The percentage of participants reporting fever was 82.1% at baseline, 8.0% in day 4 and 2.0% in day 7 (p < 0.0001 for paired differences). Multiple regression models indicated that supplementary medication intake did not seem to affect symptoms' severity or the day patients reported that their symptoms ceased completely. CONCLUSIONS This pragmatic study added evidence about the potential therapeutic effects of an extract of Cretan herbs on the amelioration of upper respiratory tract infection symptoms.