ABSTRACT - Purpose: Sore throat is a frequent reason for seeking medical care but few prescription
options are available. Lozenges are effective in delivering active ingredients to the throat. This study was
conducted to determine the analgesic efficacy of two lozenges one containing amylmetacresol (AMC)/2,4-
dichlorobenzyl alcohol (DCBA) and lidocaine and one containing hexylresorcinol versus placebo in
patients with acute sore throat due to upper respiratory tract infection (URTI). Methods: This was a
multicentre, randomised, double-blind, parallel group, placebo-controlled study. In total, 190 patients were
randomised 1:1:1 to a single dose of AMC/DCBA + lidocaine, hexylresorcinol or placebo lozenge.
Subjective ratings of throat soreness, difficulty swallowing, swollen throat, numbing, and sore throat relief
were obtained up to 2 hours post dose. Patient and investigator global ratings and a consumer questionnaire
were also collected. The primary endpoint was the change from baseline in severity of throat soreness for
both lozenges versus placebo at 2 hours post dose. Results: The hexylresorcinol lozenge demonstrated
superiority over placebo for primary and secondary efficacy variables including those related to throat
soreness, sore throat relief and difficulty swallowing; the AMC/DCBA + lidocaine lozenge was also superior
to placebo for secondary endpoints at various time points but did not reach significance for the primary
efficacy variable. Both lozenges had a rapid onset of action from 1–10 minutes post dose for the
AMC/DCBA + lidocaine lozenge and 1–5 minutes post dose for the hexylresorcinol lozenge. Numbness was
reported from 1 minute post dose with the AMC/DCBA + lidocaine lozenge and was greatest at 15 minutes.
Numbness was reported from 5 minutes post dose with the hexylresorcinol lozenge and was greatest at 10
minutes. Both lozenges were well tolerated. Conclusions: Both AMC/DCBA + lidocaine and
hexylresorcinol lozenges provided rapid and effective sore throat relief in patients with URTI