Outcomes and Predictors of Response of Duloxetine for the Treatment of Persistent Idiopathic Dentoalveolar Pain: A Retrospective Multicenter Observational Study

BACKGROUND: Duloxetine has been reported to significantly relieve the pain of persistent idiopathic dentoalveolar pain (PIDP); however, the number of studies available is scarce and no study has identified the predictors of response of duloxetine for the treatment of PIDP. OBJECTIVE: To report the efficacy, safety, and identification of positive predictors of duloxetine for PIDP patients through a retrospective multicenter observational study. METHODS: We retrospectively reviewed the clinical database of PIDP patients who were prescribed duloxetine at 3 hospitals between January 2018 and November 2021. Demographic and pain-related baseline data, efficacy of patients after 3 months of medication by visual analog scale (VAS) scores for pain and adverse events were extracted and analyzed. The predictors of pain-relieving effect of duloxetine were identified by logistic regression analysis. RESULTS: A total of 135 patients were included in this study. Side effects occurred immediately after taking duloxetine in 24 (17.8%) patients, and the treatment with duloxetine was discontinued on 13 of them because they could not tolerate the side effects. Other 11 (8.1%) patients gradually tolerated the side effects within 2 weeks. Ninety-four out of 122 (77.0%) patients obtained pain relief with VAS significantly decreased (p < 0.01) and the other 28 (23.0%) patients stopped taking the drug because of weak efficacy. Binary logistic regression analysis showed that short disease duration (OR = 1.017, 95% CI = 1.004–1.030, P = 0.012) was an independent predictor of the positive response of duloxetine. CONCLUSION: This study confirmed that duloxetine can significantly improve chronic pain of PIDP patients, and the safety was tolerable. Patients with shorter disease duration had more benefit from duloxetine. LIMITATIONS: This is a retrospective observational study. Long-term efficacy and safety of duloxetine in the treatment of PIDP patients were not evaluated.