Benzocaine lozenges are popular in symptomatic
treatment of acute sore throat. The aim of this study
was to evaluate if sucking a benzocaine lozenge was
superior to a placebo lozenge in patients with pain while
swallowing. Volunteers with acute, uncomplicated sore
throat received randomly and double-blind either a benzocaine
8 mg or a placebo lozenge. Pain was assessed on a
numerical visual rating scale. The primary outcome measure
was the sum of the pain intensity differences (SPID)
over 2 h. Secondary outcome measures included the
number of patients who reported 50% or more of their
baseline pain score (responders) and those with worthwhile
and complete pain relief, the times to worthwhile/complete
pain relief and to pain recurrence and the occurrence of any
adverse effects. A predefined interim analysis after
including 50 patients revealed the superiority of benzocaine
versus placebo in the SPID (p = 0.0086). At this
time, a total of 165 patients had been recruited (full analysis
set, FAS) and underwent statistical analysis. In the
FAS, median SPID had significantly more decreased in
patients receiving benzocaine compared to placebo (-12
vs. - 5, p = 0.001). There were significantly more
responders and patients with worthwhile pain relief in