The use of benzodiazepines for tinnitus: systematic review

Easing the Burden of Tinnitus: A Narrative Review for Exploring Effective Pharmacological Strategies

Many individuals seek medical attention for tinnitus, desiring relief from the distress caused by the condition; however, the treatment process is far from straightforward. The most effective treatments for chronic subjective tinnitus, such as tinnitus retraining therapy (TRT) and cognitive behavioral therapy (CBT), require considerable time and efforts. As a result, many of them express a desire for alleviation through medication. While it is true that medication is not generally recommended in treatment guidelines for chronic subjective tinnitus, in specific situations such as when accompanied by symptoms of depression or anxiety-drugs like antidepressants or anxiolytics may have a meaningful impact on symptom reduction. Additionally, medication can prove effective in certain specialized forms of tinnitus, such as typewriter tinnitus, as opposed to chronic subjective tinnitus. Although intratympanic dexamethasone injections for tinnitus have been reported to lack efficacy compared to a placebo, if patients perceive subjective satisfaction due to a placebo effect, it holds significance. From the perspective of patients suffering from tinnitus, even if the therapeutic mechanism is set aside, experiencing some degree of relief through certain medications can enhance compliance with evidence-based treatments like TRT and CBT.

The Effect of Anxiolytics on Tinnitus

Tinnitus is a perceptual disorder in which sound is perceived by the patient in the absence of an external or internal acoustic stimulation [...].

Efficacy and Safety of Co-Administered St. John's Wort and Ginkgo biloba Extracts in Patients with Subjective Tinnitus: A Preliminary Prospective Randomized Controlled Trial

It is widely accepted that extracts of St. John's wort (Hypericum perforatum) improve depressive symptoms, and tinnitus patients commonly presented with either mild depression or anxiety. We investigated whether co-administration of St. John's wort and Ginkgo biloba extracts can suppress tinnitus. Participants with subjective tinnitus aged 30-70 years were randomly assigned to the experimental (co-administration of St. John's wort and Ginkgo biloba extract; n = 20) or control (Ginkgo biloba extract only; n = 26) group for 12 weeks. Participants were blinded to the group assignments. After 12 weeks of treatment, no significant change in the minimum masking level on the tinnitogram was observed in either group. In the co-administration group, the Tinnitus Handicap Inventory (THI) score decreased from 34.7 (SD, 15.9) to 29.6 (16.0) (p = 0.102). However, the control group showed a significant decrease in THI score, from 30.5 (16.7) to 25.6 (17.1) (p = 0.046). Regarding the Short Form-36 Health Survey (SF-36), only the "Social Functioning" domain score changed significantly after extract co-administration, from 74.5 (21.5) to 83.9 (20.5) (p = 0.047). Co-administration of St. John's wort and Ginkgo biloba extracts did not improve the symptoms of subjective tinnitus compared to administration of Ginkgo biloba extract alone.

The Influence of Depression, Anxiety and Cognition on the Treatment Effects of Ginkgo biloba Extract EGb 761® in Patients with Tinnitus and Dementia: A Mediation Analysis

Background: Comorbid occurrence of tinnitus and emotional symptoms of anxiety and depression is highly prevalent. The Ginkgo biloba extract EGb 761^® has been shown to be effective in reducing neuropsychiatric symptoms in patients with dementia and tinnitus. Methods: We performed a mediation analysis to evaluate direct effects of EGb 761^® on tinnitus severity, as well as indirect effects mediated by symptoms of depression and anxiety and by changed cognition. We pooled data from subsets of patients suffering from tinnitus that were enrolled in three double-blind, randomized, placebo-controlled clinical trials, which investigated the efficacy of EGb 761^® (240 mg/day for 22–24 weeks) in dementia with concomitant neuropsychiatric symptoms. Results: In total, 594 patients suffered from tinnitus (EGb 761^®, 289; placebo, 305). Direct effects of EGb 761^® on tinnitus severity (p < 0.001) in patients with mild to moderate dementia were found to represent about 60% of the total effect, whereas the indirect effects (p < 0.001) mediated by improvement of anxiety, depression and cognition represented about 40% of the total effect. Conclusions: EGb 761^® could be considered as a supporting treatment for tinnitus in elderly patients suffering from dementia, with added benefit in those with symptoms of depression or anxiety.

Review of Pharmacotherapy for Tinnitus

Various medications are currently used in the treatment of tinnitus, including anesthetics, antiarrhythmics, anticonvulsants, antidepressants, antihistamines, antipsychotics, anxiolytics, calcium channel blockers, cholinergic antagonists, NMDA antagonists, muscle relaxants, vasodilators, and vitamins. To date, however, no medications have been specifically approved to treat tinnitus by the US Food and Drug Administration (FDA). In addition, medicines used to treat other diseases, as well as foods and other ingested materials, can result in unwanted tinnitus. These include alcohol, antineoplastic chemotherapeutic agents and heavy metals, antimetabolites, antitumor agents, antibiotics, caffeine, cocaine, marijuana, nonnarcotic analgesics and antipyretics, ototoxic antibiotics and diuretics, oral contraceptives, quinine and chloroquine, and salicylates. This review, therefore, describes the medications currently used to treat tinnitus, including their mechanisms of action, therapeutic effects, dosages, and side-effects. In addition, this review describes the medications, foods, and other ingested agents that can induce unwanted tinnitus, as well as their mechanisms of action.

A Phenotypic Comparison of Loudness and Pain Hyperacusis: Symptoms, Comorbidity, and Associated Features in a Multinational Patient Registry

Purpose Hyperacusis is a complex and poorly understood auditory disorder characterized by decreased tolerance to sound at levels that would not trouble most individuals. Recently, it has been suggested that individuals who experience otalgia in response to everyday sounds (termed pain hyperacusis) may differ clinically from those whose primary symptom is the perception of everyday sounds as excessively loud (termed loudness hyperacusis). Despite this theoretical distinction, there have been no empirical studies directly comparing these two populations of hyperacusis patients. Method Using data from a multinational patient registry (the Coordination of Rare Diseases at Sanford Registry), we examined self-reported demographics, symptoms, comorbidity, and response to treatment in a sample of 243 adults with hyperacusis, 152 of whom were classified as having pain hyperacusis based on reported symptoms. Bayesian statistical tests were used to investigate both the presence and absence of group differences between patients with loudness and pain hyperacusis. Results Individuals with pain hyperacusis presented with a more severe clinical phenotype, reporting a higher frequency of temporary symptom exacerbations (i.e., "setbacks"), less perceived symptom improvement over time, more severe comorbid headache disorders, and reduced benefit from sound therapy. However, the two hypothesized hyperacusis subtypes exhibited more similarities than differences, with the majority of symptoms and comorbidities being equally prevalent across groups. Multiple comorbidities were commonly observed, including tinnitus, primary headache disorders, psychiatric disorders, and functional somatic syndromes. Intolerance of sensory stimuli in other modalities was also frequently reported. Conclusion Although this study provides little evidence that loudness and pain hyperacusis are pathophysiologically distinct conditions, our findings indicate that a pain-predominant phenotype may be a meaningful prognostic marker in patients with hyperacusis.

Analysis of Gabapentin's Efficacy in Tinnitus Treatment: A Systematic Review

OBJECTIVES

Tinnitus can be a chronic symptom that brings disability and distress. Some studies suggested that gabapentin might be effective on tinnitus relief. The objective of the study is to perform a systematic review in order to evaluate the efficacy of oral gabapentin in patients with tinnitus.

METHODS

A literature search was conducted in English and following the recommendations from PRISMA. The terms used were: ("tinnitus" OR "subjective tinnitus") AND ("gabapentin"). The study selection was performed following the eligibility criteria in accordance to the PICOS (population, intervention, comparison, outcome, study design) strategy-patients with tinnitus; oral gabapentin; placebo; reduction of tinnitus severity questionnaires scores; prospective, double-blind, randomized controlled trial, respectively. The selected studies were included in qualitative synthesis. The studies were analyzed according to Joanna Briggs Institute's critical appraisal checklist for randomized controlled trials.

RESULTS

One hundred twenty-one studies were found in 9 databases and 8 studies were found in gray literature. After study selection, 6 articles were read in full. Then, 2 studies were excluded and 4 were included in qualitative synthesis. All 4 articles were analyzed according to critical evaluation checklist.

CONCLUSIONS

There is insufficient evidence to recommend the use of gabapentin for patients with tinnitus.

Evaluation of Spin in the Abstracts of Systematic Reviews and Meta-Analyses Focused on Tinnitus

HYPOTHESIS

The objective was to investigate the prevalence of spin in abstracts of systematic reviews and meta-analyses covering the treatment of tinnitus. We hypothesized that spin would be present in these articles and a significant relationship would exist between spin usage and extracted study characteristics.

BACKGROUND

Spin, the misrepresentation of study findings, can alter a clinician's interpretation of a study's results, potentially affecting patient care. Previous work demonstrates that spin is present in abstracts of randomized clinical trials.

METHODS

Using a cross-sectional analysis, we conducted a systematic search using MEDLINE and Embase databases on June 2, 2020, for systematic reviews focused on tinnitus treatment. Investigators performed screening and data extraction in a masked, duplicate fashion.

RESULTS

Forty systematic reviews met inclusion criteria, and spin was identified in four of them. Spin in abstracts most frequently occurred when conclusions claimed the beneficial effect of the experimental treatment despite high risk of bias in primary studies (n = 3). The other form of spin found was the conclusion claims safety based on nonstatistically significant results with a wide confidence interval (n = 1). There was no significant association between spin and any of our extracted study characteristics.

CONCLUSION

Spin was observed in 10% of abstracts of systematic reviews and meta-analyses covering the treatment of tinnitus. Although this percentage may be small, we recommend that medical journals provide a more detailed framework for abstract structure and require the inclusion of risk of bias assessment results in abstracts to prevent the incorporation of spin.

Current Validated Medical Treatments: Pharmacologic Interventions

The search for an effective medication that will eliminate tinnitus has a long history. Currently, no drugs exist that universally cure tinnitus. Pharmacologic interventions that have been investigated can be divided into those that attempt to eliminate the perception of tinnitus, and those that are designed to treat the negative comorbidities associated with tinnitus, thereby mitigating tinnitus' negative impact on quality of life. A third category of drugs can also be considered that addresses an identified pathologic condition that has tinnitus as an associated symptom (for example, Meniere's disease, otosclerosis, migraine-associated vertigo). This third category is not addressed.

Pharmacological Evaluation of Drugs in Animal Models of Tinnitus

Despite the pressing need for effective drug treatments for tinnitus, currently, there is no single drug that is approved by the FDA for this purpose. Instead, a wide range of unproven over-the-counter tinnitus remedies are available on the market with little or no benefit for tinnitus but with potential harm and adverse effects. Animal models of tinnitus have played a critical role in exploring the pathophysiology of tinnitus, identifying therapeutic targets and evaluating novel and existing drugs for tinnitus treatment. This review summarises and compares the studies on pharmacological evaluation of tinnitus treatment in different animal models based on the pharmacological properties of the drug and provides insights into future directions for tinnitus drug discovery.

Pharmacotherapy of Tinnitus

Tinnitus is a common symptom for which there is in most cases no causal therapy. The search for an improvement of tinnitus through pharmacological interventions has a long tradition. The observation that tinnitus can be transiently suppressed by the use of lidocaine has shown that the symptom is susceptible to pharmacotherapy. So far, however, no medication has been found for either acute or chronic subjective tinnitus that reliably leads to a long-term reduction or even complete disappearance of the symptom for the majority of tinnitus sufferers. Nevertheless, in everyday clinical life, drugs are frequently used, usually off-label, to relieve tinnitus or tinnitus-associated symptoms (e.g. sleep disturbance, depression, anxiety disorder or hearing loss). This chapter shows the different approaches to acute and chronic subjective tinnitus by means of pharmacotherapeutic interventions. Furthermore, this review reports on the scientific studies carried out in this area in recent years and explains the difficulties in finding a suitable medication for most forms of tinnitus. In addition, it reports on the pharmacotherapeutic options for objective tinnitus and describes the development of tinnitus as a side effect of certain drugs. Finally, possible target structures are mentioned, which should possibly be addressed in pharmacological studies in the near future.

Increased metabolic activity and hysteretic enhanced GABAA receptor binding in a rat model of salicylate-induced tinnitus

Tinnitus is relevant to neural hyperactivity in the central nervous system (CNS). Normal quantity and functioning of the γ-aminobutyric acid (GABA) receptor are crucial for maintaining the balance between excitation and inhibition in the brain. In this study, we applied a rat model of tinnitus via long-term salicylate administration. The combination of the gap pre-pulse inhibition of acoustic startle (GPIAS) and pre-pulse inhibition (PPI) tests were used to detect tinnitus-like behavior, and rats receiving 7 or 14 consecutive days of salicylate administration showed evidence of tinnitus. After positron emission tomography (PET) scan, we found that the metabolic activity was increased after salicylate treatment followed by enhanced GABA_A receptor binding with cessation of salicylate administration in the auditory cortex (AC), medial prefrontal cortex (mPFC), hippocampus (HP), cingulate cortex (CiC) and insular (InC). The inferior colliculus (IC) showed an elevated metabolic activity with no change in the GABA_A receptor binding. All the alterations returned to baseline several days after cessation of salicylate treatment despite a mismatch between the time-course of them. By contrast, we found alterations in neither the metabolic activity nor the GABA_A receptor binding in the amygdala (AMY) and cerebellum (CRB). These findings indicate that enhanced neural activity in the auditory and limbic system may contribute to the development of tinnitus, while the hysteretic increase of GABA_A receptor binding in specific areas of the CNS may be a compensation for hyperactivity, which may be involved in tinnitus relieving.

Therapeutic Approaches to the Treatment of Tinnitus

Tinnitus is a highly prevalent condition that is associated with hearing loss in most cases. In the absence of external stimuli, phantom perceptions of sounds emerge from alterations in neuronal activity within central auditory and nonauditory structures. Pioneering studies using lidocaine revealed that tinnitus is susceptible to pharmacological interventions. However, lidocaine is not effective in all patients, and no other drug has been identified with clear efficacy for the long-term treatment of tinnitus. In this review, we present recent advances in tinnitus research, including more detailed knowledge of its pathophysiology and involved neurotransmitter systems. Moreover, we summarize results from animal and clinical treatment studies as well as from studies that identified tinnitus as a side effect of pharmacological treatments. Finally, we focus on challenges in the development of pharmacological compounds for the treatment of tinnitus, namely the limitations of available animal models and of standardized clinical research methodologies.

Tinnitus and sound intolerance: evidence and experience of a Brazilian group

Introduction

Tinnitus and sound intolerance are frequent and subjective complaints that may have an impact on a patient's quality of life.

Objective

To present a review of the salient points including concepts, pathophysiology, diagnosis and approach of the patient with tinnitus and sensitivity to sounds.

Methods

Literature review with bibliographic survey in LILACS, SciELO, Pubmed and MEDLINE database. Articles and book chapters on tinnitus and sound sensitivity were selected. The several topics were discussed by a group of Brazilian professionals and the conclusions were described.

Results

The prevalence of tinnitus has increased over the years, often associated with hearing loss, metabolic factors and inadequate diet. Medical evaluation should be performed carefully to guide the request of subsidiary exams. Currently available treatments range from medications to the use of sounds with specific characteristics and meditation techniques, with variable results.

Conclusion

A review on tinnitus and auditory sensitivity was presented, allowing the reader a broad view of the approach to these patients, based on scientific evidence and national experience.

Pharmacological modulation of Kv3.1 mitigates auditory midbrain temporal processing deficits following auditory nerve damage

Higher stages of central auditory processing compensate for a loss of cochlear nerve synapses by increasing the gain on remaining afferent inputs, thereby restoring firing rate codes for rudimentary sound features. The benefits of this compensatory plasticity are limited, as the recovery of precise temporal coding is comparatively modest. We reasoned that persistent temporal coding deficits could be ameliorated through modulation of voltage-gated potassium (Kv) channels that regulate temporal firing patterns. Here, we characterize AUT00063, a pharmacological compound that modulates Kv3.1, a high-threshold channel expressed in fast-spiking neurons throughout the central auditory pathway. Patch clamp recordings from auditory brainstem neurons and in silico modeling revealed that application of AUT00063 reduced action potential timing variability and improved temporal coding precision. Systemic injections of AUT00063 in vivo improved auditory synchronization and supported more accurate decoding of temporal sound features in the inferior colliculus and auditory cortex in adult mice with a near-complete loss of auditory nerve afferent synapses in the contralateral ear. These findings suggest modulating Kv3.1 in central neurons could be a promising therapeutic approach to mitigate temporal processing deficits that commonly accompany aging, tinnitus, ototoxic drug exposure or noise damage.

Paraoxonase Activity and Oxidative Status in Patients with Tinnitus

BACKGROUND AND OBJECTIVES

The aim of this study was to investigate serum paraoxanase-1 (PON) activity, total oxidant status (TOS), total antioxidant status (TAS), and the oxidative stress index (OSI) in tinnitus; and to compare the results with data from healthy subjects.

SUBJECTS AND METHODS

A total of 114 subjects-54 patients with tinnitus and 60 healthy controls were enrolled in this study. Serum PON activity, TOS, TAS, and OSI levels were measured.

RESULTS

In the tinnitus group, TAS, and PON were significantly lower than in the control group (p<0.001). However, the TOS, and OSI levels were significantly higher in the tinnitus group than in the control group (p<0.001).

CONCLUSIONS

According to the data obtained from the present study, patients with tinnitus were exposed to potent oxidative stress. Oxidative stress may be the key contributing factor to the pathogenesis of tinnitus.

Parallels between phantom pain and tinnitus

Phantom pain and tinnitus are diseases that cause patients great discomfort. Both are phantom sensations that have many connections with cerebral structures, but their underlying mechanisms are not fully understood. Several therapies have been suggested for these conditions over the years, but there is still no consensus on how to treat either one. Comparison of these two phenomena reveals many similarities, including what is known about their underlying mechanisms, associated brain areas, and responses to therapeutic agents and methods. These similarities need to be evaluated in greater depth, as this could improve our understanding of tinnitus and phantom pain, and thereby improve management strategies for these conditions.