Onset of analgesia by a topically administered flurbiprofen lozenge: a randomised controlled trial using the double stopwatch method. Issue 4 (November 2018)

• Record Type: Journal Article
• Authors: Schachtel, Bernard; Aspley, Sue; Shephard, Adrian; Schachtel, Emily; Lorton, Mary Beth; Shea, Tim
• Is Part Of: British journal of pain. Volume 12:Issue 4(2018)
• Page Start: 208
• Page End: 216
• Publication Date: 2018-11
• Subjects: Double stopwatch method -- topical analgesia -- onset of action -- flurbiprofen -- pharyngitis -- sore throat; Pain -- Periodicals; Pain -- Treatment -- Periodicals; 616.0472
• DOI: 10.1177/2049463718756152
• Languages: English
• ISSNs: 2049-4637

Abstract

Background: The double stopwatch (DSW) method for determining the onset of analgesic activity has been implemented extensively by investigators studying orally administered drugs. Objective: The aim of this randomised, placebo-controlled trial was to use the DSW method to determine the time to onset of analgesia of a single dose of a topically administered non-steroidal anti-inflammatory drug, flurbiprofen 8.75 mg lozenge. Methods: Adults with acute sore throat (n = 122) were examined to confirm the presence of tonsillopharyngitis (Tonsillo-Pharyngitis Assessment) and sore throat pain of at least moderate intensity (≥6 on a 0–10 Sore Throat Scale). Lozenges containing flurbiprofen 8.75 mg or inert ingredients (identically flavoured) were administered under double-blind conditions in the clinic while patients assessed pain and pain relief over 3 hours. Onset of analgesia was determined using the DSW method and reported as the Kaplan–Meier median time to meaningful relief. The median time to first perceived relief was also documented. Results: About 78% of flurbiprofen-treated patients reported meaningful pain relief compared with 48% of placebo-treated patients (p < 0.01); median time to meaningful relief for flurbiprofen-treated patients was 43 minutes (placebo-treated patients were right-censored due to non-responsivity; p = 0.01). Median time to first perceived pain relief was 11 minutes for flurbiprofen-treated patients and 19 minutes for placebo-treated patients (p = 0.03). Flurbiprofen lozenge was well tolerated, with no serious adverse events occurring and no patient discontinuing due to an adverse event. Conclusion: These results indicate that the DSW method can be successfully applied to the evaluation of the onset of action of a locally administered analgesic in patients with acute sore throat, demonstrating that the onset of action (time to meaningful pain relief) of flurbiprofen lozenge was <45 minutes.