Evaluation of the effect of locally administered amitriptyline gel as adjunct to local anesthetics in irreversible pulpitis pain

Abstract

Amitriptyline is one of the most common tricyclic antidepressants, which binds to pain sensory nerve fibers close to the sodium channel; hence, it could interact to some degree with receptors of local anesthetics. This study was designed to assess the additional analgesic effects of 2% Amitriptyline local gel administration in irreversible pulpitis pain of the molars. This study was a randomized, double-blind clinical trial that was performed on 56 consented adult patients who did not receive enough analgesia after a lidocaine nerve block for their tooth pulpitis pain. Patients were treated with 0.2 ml of either 2% amitriptyline or placebo, which was directly injected into their mandibular molar pulp chamber after they had received two routine lidocaine injections. Patients were asked to score their pain as a mark on a 10-cm Visual Analogue Scale (VAS) at different timepoints: 0 (just before gel administration), 1, 3, 5, 7, and 9 minutes after the treatments. There was a 92.5% decrease in VAS scores of patients 9 minutes after amitriptyline administration compared to Time 0, while in the placebo group this difference was only 13.5%. Further, in the amitriptyline group, the VAS score at all timepoints was statistically different from Time 0 (P < 0.01). The overall pain reduction and its trend was significantly higher in the amitriptyline group compared with the placebo group (P < 0.001). Inter-pulp space administration of amitriptyline 2% gel for completing analgesia in irreversible pulpitis pain could be effective and useful as a conjunctive therapy to injections of local anesthetics.