Betahistine for Ménière's disease or syndrome

Treatment of Menière's disease: a scoping review of the current evidence

PURPOSE

The management of unilateral Menière's disease (MD) in adult patients remains contentious, with various therapeutic options proposed but no established gold standard. This scoping review aims to evaluate the current treatment options for unilateral MD, identifying challenges in management and providing guidance for ENT physicians in selecting effective therapies.

METHODS

A comprehensive literature search of the MEDLINE and Embase databases was conducted without date restrictions, assessing various treatment modalities for MD. Randomized controlled trials (RCTs) were selected to ensure the highest quality of evidence was reviewed.

RESULTS

Thirty-four RCTs met the inclusion criteria. The current evidence base encompasses dietary interventions, systemic drug therapy, intratympanic treatments, positive pressure therapy, low-level laser therapy, and non-destructive surgical techniques. However, the evidence supporting these treatments is limited and inconsistent. Notably, none of the RCTs considered the heterogeneity of MD patient populations, which may explain the variability in study results.

CONCLUSION

This review highlights the limited evidence supporting current treatments for unilateral MD, emphasizing the need for high-quality, placebo-controlled trials. Future research should incorporate biomarker-based stratification, large patient cohorts, standardized outcome measures, and long follow-up periods to enhance the consistency and comparability of findings.

A process for prioritising systematic reviews in tinnitus

Objective: To develop an innovative prioritisation process to identify topics for new or updated systematic reviews of tinnitus research.Design: A two-stage prioritisation process was devised. First, a scoping review assessed the amount of randomized controlled trial-level evidence available. This enabled development of selection criteria for future reviews, aided the design of template protocol and suggested the scale of work that would be required to conduct these reviews. Second, using the pre-defined primary and secondary criteria, interventions were prioritised for systematic review.Study sample: Searches identified 1080 records. After removal of duplicates and out of scope works, 437 records remained for full data charting.Results: The process was tested, using subjective tinnitus as the clinical condition and using Cochrane as the systematic review platform. The criteria produced by this process identified three high priority reviews: (1) Sound therapy using amplification devices and/or sound generators; (2) Betahistine and (3) Cognitive behaviour therapy. Further secondary priorities were: (4) Gingko biloba, (5) Anxiolytics, (6) Hypnotics, (7) Antiepileptics and (8) Neuromodulation.Conclusions: A process was developed which successfully identified priority areas for Cochrane systematic reviews of interventions for subjective tinnitus. This technique could easily be transferred to other conditions and other types of systematic reviews.

Betahistine for tinnitus

BACKGROUND

Tinnitus is a symptom defined as the perception of sound in the absence of an external source. In England alone there are an estimated ¾ million general practice consultations every year where the primary complaint is tinnitus, equating to a major burden on healthcare services. Clinical management strategies include education and advice, relaxation therapy, tinnitus retraining therapy, cognitive behavioural therapy, sound enrichment using ear-level sound generators or hearing aids, and drug therapies to manage co-morbid symptoms such as sleep difficulties, anxiety or depression. As yet, no drug has been approved for tinnitus by a regulatory body. Nonetheless, over 100,000 prescriptions for betahistine are being filled every month in England, and nearly 10% of general practitioners prescribe betahistine for tinnitus.

OBJECTIVES

To assess the effects of betahistine in patients with subjective idiopathic tinnitus.

SEARCH METHODS

The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL, via the Cochrane Register of Studies); Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 23 July 2018.

SELECTION CRITERIA

Randomised controlled trials (RCTs) recruiting patients of any age with acute or chronic subjective idiopathic tinnitus were included. We included studies where the intervention involved betahistine and this was compared to placebo, no intervention or education and information. We included all courses of betahistine, regardless of dose regimens or formulations and for any duration of treatment.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. Our primary outcomes included tinnitus loudness and significant adverse effects (upper gastrointestinal discomfort). Our secondary outcomes included tinnitus symptom severity as measured by the global score on a multi-item tinnitus questionnaire, depressive symptoms, symptoms of generalised anxiety, health-related quality of life, other adverse effects (e.g. headache, drowsiness, allergic skin reactions (pruritis, rashes) and exacerbation of tinnitus) and tinnitus intrusiveness. We used GRADE to assess the quality of evidence for each outcome; this is indicated in italics.

MAIN RESULTS

This review included five studies (with a total of 303 to 305 participants) comparing the effects of betahistine with placebo in adults with subjective idiopathic tinnitus. Four studies were parallel-group RCTs and one had a cross-over design. The risk of bias was unclear in all of the included studies.Due to heterogeneity in the outcomes measured and measurement methods used, very limited data pooling was possible. When we pooled the data from two studies for the primary outcome tinnitus loudness, the mean difference on a 0- to 10-point visual analogue scale at one-month follow-up was not significant between betahistine and placebo (-0.16, 95% confidence interval (CI) -1.01 to 0.70; 81 participants) (very low-quality evidence). There were no reports of upper gastrointestinal discomfort (significant adverse effect) in any study.As a secondary outcome, one study found no difference in the change in the Tinnitus Severity Index between betahistine and placebo (mean difference at 12 weeks 0.02, 95% CI -1.05 to 1.09; 50 participants) (moderate-quality evidence). None of the studies reported the other secondary outcomes of changes in depressive symptoms or depression, anxiety symptoms or generalised anxiety, or health-related quality of life as measured by a validated instrument, nor tinnitus intrusiveness.Other adverse effects that were reported were not treatment-related.

AUTHORS' CONCLUSIONS

There is an absence of evidence to suggest that betahistine has an effect on subjective idiopathic tinnitus when compared to placebo. The evidence suggests that betahistine is generally well tolerated with a similar risk of adverse effects to placebo treatments. The quality of evidence for the reported outcomes, using GRADE, ranged from moderate to very low.If future research into the effectiveness of betahistine in patients with tinnitus is felt to be warranted, it should use rigorous methodology. Randomisation and blinding should be of the highest quality, given the subjective nature of tinnitus and the strong likelihood of a placebo response. The CONSORT statement should be used in the design and reporting of future studies. We also recommend the development of validated, patient-centred outcome measures for research in the field of tinnitus.