Reducing the flavour of oral lidocaine: randomized controlled trial assessing the efficacy of mint-flavoured mouthwash.

OBJECTIVE

To test the hypothesis that using an alcohol-based, mint-flavoured oral mouthwash prior to applying oral lidocaine spray will result in an improvement in the unpleasant taste of the lidocaine.

DESIGN

A double-blind, randomized, controlled trial using a crossover design.

SETTING

A tertiary care hospital.

METHODS

Fifteen able-bodied volunteers rinsed for 30 seconds with either a mint-flavoured, alcohol-based mouthwash (treatment) or plain water (placebo) prior to the administration of topical lidocaine spray. All subjects received both the treatment and the placebo; however, the order of exposure was randomized.

OUTCOME MEASURES

Subjects completed two 100 mm visual analogue scales (VASs). The first assessed the overall satisfaction with the taste of the lidocaine. This consisted of a 100 mm VAS with 0 defined as the "most unpleasant taste" and 100 mm defined as the "most pleasant taste," whereas 50 mm was defined as neutral or no taste. The second VAS assessed subjective analgesia after lidocaine administration.

RESULTS

There was a statistically significant improvement in the taste of oral lidocaine after administering the treatment intervention (p = .003). There was a reduction in subjective analgesia, which did not reach statistical significance (p = .03). Use of the oral mouthwash reduced the perception of the negative flavour of the lidocaine from 20.77 (13.2) mm to 50.2 (12.84) mm as assessed by the VAS.

CONCLUSIONS

A brief rinse with a mint-flavoured, alcohol-based mouthwash prior to administration of topical lidocaine resulted in a significant improvement in the perceived flavour of topical lidocaine with a minimal reduction in subjective analgesia.