New Bupivacaine Lozenge as Topical Anesthesia Compared to Lidocaine Pharyngeal Spray Before Upper Gastrointestinal Endoscopy in Unsedated Patients

The research group has previously conducted a clinical study with patients who underwent an UGE at the Department of Gastroenterology, Hvidovre University Hospital, Denmark, where the effect of a new lidocaine lozenge was compared to the lidocaine suspension that was used as standard treatment. The results showed that the lozenge increased the patient's acceptance of the gag reflexes, decreased the patient discomfort during UGE and thereby increased patient acceptance of the UGE. Furthermore, there was a significant improvement in assessment of taste and texture of the lozenge compared to the suspension. A study by Thanvi et al. has shown that it is difficult to obtain valid VAS scores when the patients are sedated, as it might cause amnesia and may impair the patient's ability to make an accurate assessment of the discomfort. Sedation were a limitation for the study conducted by the research group, because of impairment in the patients judgmental abilities. Furthermore a longer duration of the effect of the lozenge was requested. Therefore, the research group reformulated the lozenge and changed the active pharmaceutical ingredient (API) to bupivacaine. Bupivacaine is an amide as lidocaine, but has a longer anesthetic effect and is four times as potent as lidocaine. It would therefore be relevant to optimize the study design and perform a new clinical study with unsedated patients undergoing UGE, where the bupivacaine lozenge was tested.

The clinical study was performed in the private gastrointestinal (GI) clinic at Hvidovre, Denmark. Before the UGE was performed the patient was locally anesthetized in the pharynx with a lidocaine spray as a standard treatment.

The hypothesis was that a bupivacaine lozenge would reduce the patient experienced discomfort during UGE due to a better local anesthetic effect compared to lidocaine spray. Moreover it is hypothesized that the bupivacaine lozenge would be more patient friendly than the lidocaine spray because of a better taste masking according to lesser bitter taste and a pleasant mode of being anesthetized.

The aim of the study was to compare patient discomfort by two different local anesthetic methods. The standard treatment was a lidocaine pharyngeal spray and was compared to the experimental treatment a bupivacaine lozenge. The efficacy and acceptance of the treatments were also examined, as well as the taste of the anesthetics. Furthermore the patient's and endoscopist's assessment of the UGE was examined.