WWOM VII: Effectiveness of systemic pharmacotherapeutic interventions in the management of BMS: A systematic review and meta-analysis

Topical amitriptyline in burning mouth syndrome: A retrospective real-world evidence study

OBJECTIVE

To evaluate the effectiveness, tolerability, and safety of topical amitriptyline as a potential route of administration for the management of burning mouth syndrome.

BACKGROUND

Burning mouth syndrome is a complex, idiopathic, and debilitating orofacial pain disorder that impairs quality of life, with a prevalence of up to 18% in menopausal women. Available drugs to alleviate its burning sensation have inconsistent and limited efficacy. Given its physicochemical properties, excellent tolerability, and ability to target peripheral pathways, topical amitriptyline seems a promising mechanistically specific analgesic drug for burning mouth syndrome.

METHODS

In this retrospective cross-sectional real-world evidence study, patients with burning mouth syndrome who were prescribed topical amitriptyline for 8 weeks were identified. Eligibility criteria stemmed from ICHD-3, ICOP, and consensus definitions. The primary outcome measure was mean daily pain intensity (on a 0-10 scale); secondary outcomes included adverse events and patient global impression of improvement. Data are given as the mean ± SD.

RESULTS

A total of 15 patients fulfilling the eligibility criteria were included and analyzed. Mean daily pain was 6.7 ± 2.1 at baseline and 3.7 ± 2.3 after treatment, with a mean reduction of 3.1 ± 2.8 (p = 0.002). Half of the patients experienced a decrease in pain by at least 50% (p = 0.008). Several mild adverse events were reported, such as somnolence or dry mouth.

CONCLUSIONS

Topical amitriptyline may be a safe and potent route of administration in the treatment of burning mouth syndrome, a hypothesis to be tested in further controlled trials.

A review of animal models for burning mouth syndrome: Mechanistic insights and knowledge gaps

OBJECTIVES

The underlying mechanisms of burning mouth syndrome (BMS) remain unclear leading to challenges and unsatisfactory management. Current treatments focus primarily on symptom relief, with few consistently achieving a 50% reduction in pain. This review aims to explore animal models of BMS to gain a better understanding of the underlying mechanisms and to discuss potential and existing knowledge gaps.

METHODS

A comprehensive review of PubMed®, Google Scholar, and Scopus was performed to assess advances and significant gaps of existing rodent models that mimic BMS-related symptoms.

RESULTS

Rodent models of BMS involve reproduction of dry-tongue, chorda tympani transection, or overexpression of artemin protein. Existing preclinical models tend to highlight one specific etiopathogenesis and often overlook sex- and hormone-specific factors.

CONCLUSION

Combining aspects from various BMS models could prove beneficial in developing comprehensive experimental designs and outcomes encompassing the multifaceted nature of BMS.

Rikkosan's Short-Term Analgesic Effect on Burning Mouth Syndrome: A Single-Arm Cohort Study

Burning mouth syndrome (BMS) is a chronic oral pain disorder. There is a theory that BMS is a form of nociplastic pain. A standard treatment for BMS has not yet been established. Kampo medicine is a traditional oriental medicine. The purpose of this study is to evaluate the effectiveness of Rikkosan-a traditional Japanese herbal medicine (Kampo)-in the treatment of BMS. A single-center retrospective study was conducted on 20 patients who were diagnosed with BMS and treated with Rikkosan alone (total daily dose; 7.5 g) three times daily for approximately 4 weeks (29.5 ± 6.5 days). Rikkosan was dissolved in hot water and taken internally. They had an average age of 63 years, and 90% were being treated for other illnesses, but their medication status was the same during this study period, except for Rikkosan. No adverse events were observed in patients. Numerical rating scale (NRS) or visual analog scale (VAS)/10 scores decreased significantly between the time of the initiation of Rikkosan and one month after (-2.1 ± 1.2, p < 0.05). Rikkosan has a short-term effect of reducing NRS by two levels in BMS patients.

Salivary biomarkers in burning mouth syndrome: A systematic review and meta-analysis

The objective of this systematic review was to evaluate which salivary biomarkers are altered in patients with burning mouth syndrome (BMS) compared to a control group (CG). A comprehensive literature search was conducted in four databases. Case-control studies evaluating salivary biomarkers in BMS patients were included. Risk of bias was assessed using the Newcastle-Ottawa tool. RevMan was used for meta-analysis. Seventeen studies were selected. The included studies collected 54 different biomarkers. Of these biomarkers, only three (cortisol, α-amylase, and dehydroepiandrosterone) were analyzed in three or more studies. Dehydroepiandrosterone obtained contradictory results among the studies. However, cortisol and α-amylase levels were found to be higher in BMS patients. Cortisol was the only biomarker which could be included for meta-analysis. Cortisol levels were significantly higher in the BMS group compared to the CG (Mean Difference = 0.39; 95% CI [0.14-0.65]; p = 0.003). In conclusion, different studies investigated salivary biomarkers in patients with BMS compared to a CG, with controversial results. Meta-analysis, confirmed by trial-sequential analysis, showed how cortisol levels were significantly higher in BMS. Cortisol emerges as an interesting salivary biomarker in BMS, but future properly designed studies are needed to evaluate its role in diagnosis and/or response to treatment.

Efficacy, safety, and tolerability of antidepressants for pain in adults: overview of systematic reviews

OBJECTIVE

To provide a comprehensive overview of the efficacy, safety, and tolerability of antidepressants for pain according to condition.

DESIGN

Overview of systematic reviews.

DATA SOURCES

PubMed, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials from inception to 20 June 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Systematic reviews comparing any antidepressant with placebo for any pain condition in adults.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted data. The main outcome measure was pain; for headache disorders it was frequency of headaches. Continuous pain outcomes were converted into a scale of 0 (no pain) to 100 (worst pain) and were presented as mean differences (95% confidence intervals). Dichotomous outcomes were presented as risk ratios (95% confidence intervals). Data were extracted from the time point closest to the end of treatment. When end of treatment was too variable across trials in a review, data were extracted from the outcome or time point with the largest number of trials and participants. Secondary outcomes were safety and tolerability (withdrawals because of adverse events). Findings were classified from each comparison as efficacious, not efficacious, or inconclusive. Certainty of evidence was assessed with the grading of recommendations assessment, development, and evaluation framework.

RESULTS

26 reviews (156 unique trials and >25 000 participants) were included. These reviews reported on the efficacy of eight antidepressant classes covering 22 pain conditions (42 distinct comparisons). No review provided high certainty evidence on the efficacy of antidepressants for pain for any condition. 11 comparisons (nine conditions) were found where antidepressants were efficacious, four with moderate certainty evidence: serotonin-norepinephrine reuptake inhibitors (SNRIs) for back pain (mean difference -5.3, 95% confidence interval -7.3 to -3.3), postoperative pain (-7.3, -12.9 to -1.7), neuropathic pain (-6.8, -8.7 to -4.8), and fibromyalgia (risk ratio 1.4, 95% confidence interval 1.3 to 1.6). For the other 31 comparisons, antidepressants were either not efficacious (five comparisons) or the evidence was inconclusive (26 comparisons).

CONCLUSIONS

Evidence of efficacy of antidepressants was found in 11 of the 42 comparisons included in this overview of systematic reviews-seven of the 11 comparisons investigated the efficacy of SNRIs. For the other 31 comparisons, antidepressants were either inefficacious or evidence on efficacy was inconclusive. The findings suggest that a more nuanced approach is needed when prescribing antidepressants for pain conditions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022311073.

Burning Mouth Syndrome

Burning mouth syndrome (BMS) is a rare chronic neuropathic pain condition characterized by recurring burning pain or dysesthesia in the absence of any local or systemic causes of symptoms. The exact pathophysiology of BMS is unknown, but recent research suggests a medley of neuropathic, endocrinological, and psychosocial elements. This article presents a case history and reviews the epidemiology, diagnostic criteria, clinical features, diagnostic investigations, pathophysiology, and management of BMS.

Low Dose Naltrexone for Treatment of Burning Mouth Syndrome

OBJECTIVE

The International Classification of Disease defines burning mouth syndrome (BMS) as a chronic intraoral burning sensation, with no identifiable local or systemic cause. Since current management is often unsatisfactory, the aim of this report is to describe a new treatment modality (i.e., low-dose naltrexone [LDN]).

STUDY DESIGN

A 62-year-old woman presented with the complaint of burning on the tongue of 3 years' duration. Existing comorbidities were fibromyalgia, irritable bowel syndrome, headache, and interstitial cystitis. Her reported pain intensity ranged from 2/10 (morning) to 8/10 (evening) on a numeric rating scale. With the diagnosis of BMS and hyposalivation, and in light of her current clonazepam use and fibromyalgia, a dry mouth protocol and LDN (3 mg) were prescribed.

RESULTS

After 1 month, her pain intensity decreased by 50%, with no pain upon awakening. After 2 months, the widespread pain associated with her chronic morbidities also reduced by 50%, and her headache disappeared. After adjusting LDN dose to 4.5 mg, the patient was stable at 6 months, with 50% reduction of widespread pain and 2/10 BMS pain, and no reported side effects.

CONCLUSIONS

These preliminary results suggest that LDN may be a feasible and effective treatment for BMS, especially in patients' refractory to traditional treatment.

The association of sleep disturbances with burning mouth syndrome: An overlooked relationship-A qualitative systematic review

OBJECTIVES

To review the relevant literature to assess whether patients with burning mouth syndrome (BMS) are more prone to have sleep disturbances than general population.

METHODS

The literature search for relevant articles was from July 2020 to March 2021. A systematic search of PubMed, Embase, Google Scholar, Cochrane library, Dentistry & Oral Sciences Source, and Scopus was conducted to search for relevant studies. The quality of studies was assessed in accordance with the Joanna Briggs Institute's guidelines and using the software SUMARI-The System for the Unified Management, Assessment and Review of Information. Confidence in the findings was assessed using the GRADE-CERQual approach.

RESULTS

A total of 1064 studies were initially identified from the search; six studies, two cross-sectional and four case-control, met the inclusion criteria and were selected for this systematic review. Sleep disturbances were a required outcome measured in selected studies evaluating symptoms of BMS. For studies that were included in the final analyses, BMS was found to relate to several dimensions of sleep including sleep disturbance and duration (n = 6), sleep affecting daytime function (n = 4), sleep quality (n = 6), sleep efficiency (n = 4), and ability to fall asleep (n = 4). Consistent evidence of moderate confidence found that BMS was associated with greater sleep disturbance, reduced sleep quality, increased time taken to fall asleep, reduced sleep efficiency, and poor daytime function, whereas evidence of low confidence was found regarding the association of BMS with reduced sleep duration.

CONCLUSIONS

Although the presented studies could not establish a direct causal relationship between BMS and sleep disturbances, it supports the evidence that sleep disturbance is associated with symptoms of BMS. Management strategies to improve sleep may be considered in future research for managing BMS patients.