Double-blind comparison of two types of benzocaine lozenges for the treatment of acute pharyngitis

Abstract

In a reference-controlled double-blind trial in patients with acute pharyngitis the effects of a newly developed lozenge containing 8 mg of benzocaine (p-aminobenzoic acid ethyl ester, CAS 94-09-7) were compared with those of an identically dosed commercial pastille. 246 patients were randomized to receive either the lozenges (group A, n = 123) or the pastilles (group B, n = 123). Each patient took a total of six doses within 12 h according to the double-dummy principle, with each single dose spaced by 2 h. The primary parameter was the assessment of the responder rate with = 50% pain relief within 15 min post application. Further parameters included the relative relief of pain in the course of the study and the tolerability of the formulation. After application of the first unit the comparison of groups yielded very similar and statistically not differing results for efficacy in both groups, with responder rates of 25.2% and 22.0% in groups A and B, respectively. One adverse drug reaction was observed in group B (burning and tingling feeling on the tongue), which, however, did not lead to discontinuation of study participation. In all other cases tolerability was stated to be “good to verygood”. The application of the benzocaine lozenges was statistically non-inferior to the use of the pastilles.

Key words

Benzocaine, double-blind - trial, equivalence, lozenges - CAS 94-09-7 - Local anaesthetic agent - Pharyngitis

• References

• 1 Kane GC, Hoehn SM, Behrenbeck TR, Mulvagh SL. Benzocaine-induced methemoglobinemia based on the Mayo Clinic experience from 28478 transesophageal echocardiograms: incidence, outcomes, and predisposing factors. Arch Intern Med. 2007; 167 (18) 1977-82
• 2 Kagan G, Huddlestone L, Wolstencroft P. Two lozenges containing benzocaine assessed in the relief of sore throat. J Int Med Res. 1982; 10 (6) 443-6