Use of betahistine in the treatment of peripheral vertigo

Skeletal Editing of Benzene Motif: Photopromoted Transannulation for Synthesis of DNA-Encoded Seven-Membered Rings

In this report, we present a photopromoted, metal-free transannulation of phenyl azides for the synthesis of DNA-encoded seven-membered rings. The transformation is efficiently achieved through a skeletal editing strategy targeting the benzene motif coupled with a Reversible Adsorption to Solid Support (RASS) strategy. A variety of valuable DNA-encoded seven-membered ring compounds, including DNA-encoded 3H-azepines, azepinones, and unnatural amino acids, are now accessible. Crucially, this DNA-compatible protocol can also be applied for the introduction of complex molecules, as exemplified by Lorcaserin and Betahistine. The selective conversion of readily available phenyl rings into high-value seven-membered rings offers a promising avenue for the construction of diversified and drug-like DNA-encoded library.

Vertigo During Pregnancy: A Narrative Review of the Etiology, Pathophysiology, and Treatment

From the time of conception until the time of labor, a woman's body and mind undergo a variety of hormonal and other changes. Patients may also experience vertigo and a lack of balance during this period. Disabling and physically painful, these symptoms may strike at any moment. Pregnancy-related vertigo has been the focus of several studies. We looked at the research on vertigo in pregnant women in detail. This narrative review aims to examine the causes, pathophysiology, and current treatments for vertigo during pregnancy. Vertigo during pregnancy has a diverse etiology, with typical causes including hormonal changes and modifications in vascular dynamics. Vertigo may start to appear due to pathophysiological mechanisms involving vestibular and central nervous system adaptations. Numerous alternatives for treatment are available, including dietary changes, vestibular therapy, medicines, and surgical procedures. The thorough assessment of the current research on vertigo during pregnancy provided by this narrative review will help medical practitioners make wise clinical decisions.

Diagnostic and therapeutic strategies for vestibular neuritis of the Japan Society for Equilibrium Research

OBJECTIVE

To provide diagnostic and therapeutic strategies for vestibular neuritis in accordance with the Japanese Clinical Practice Guidelines for Vestibular Neuritis 2021.

METHODS

The Committee for Clinical Practice Guidelines for Vestibular Neuritis was entrusted with a review of the relevant scientific literature on the above topic. Clinical Questions (CQs) concerning the treatment of vestibular neuritis were produced, and a search of the literature was conducted to identify studies related to the CQs. The recommendations were based on the literature review and the expert opinion of a subcommittee.

RESULTS

We proposed the diagnostic criteria for vestibular neuritis, as well as answers to CQs, recommendations, and evidence levels for the treatment of vestibular neuritis.

CONCLUSION

The diagnostic criteria for vestibular neuritis were based on clinical history and examination findings after completing the differential diagnosis process. The treatment of vestibular neuritis was divided into acute, subacute, and chronic stages. The Japanese Clinical Practice Guidelines for Vestibular Neuritis 2021 should be used as a reference in the diagnosis and treatment of vestibular neuritis.

[Vestibular rehabilitation for peripheral vestibular hypofunction: an interdisciplinary consensus]

The literature review presents approaches to the management of patients with vestibular disorders. The principles of organization of vestibular rehabilitation in peripheral vestibular hypofunction, indications for appointment, factors influencing its implementation, technique, methods of evaluating effectiveness are considered in detail. Attention is drawn to the fact that the selection of exercises and the duration of vestibular rehabilitation is carried out individually and depends on many factors, including the nature of vestibular deficiency and the specific characteristics of the patient. The possibilities of using additional pharmacological therapy with histamine preparations, which can accelerate the onset of vestibular compensation, are shown. It is noted that vestibular rehabilitation is a safe and effective method of treating peripheral vestibular hypofunction and should be recommended to patients of all ages with vestibular disorders leading to limited social and physical activity.

Effect of betahistine treatment on dizziness and anxiety symptoms of BPPV patients

Background

Patients with benign paroxysmal positional vertigo (BPPV) may experience significant deterioration in their quality of life due to dizziness and anxiety symptoms.

Aim

To evaluate the effect of betahistine add-on therapy on dizziness and anxiety symptoms of BPPV patients.

Materials and Methods

Eighty-four patients who were diagnosed as having posterior canal BPPV were included in the study. Patients were divided into two groups according to the treatment regimen: Group 1 included 42 subjects who were treated with the Epley maneuver alone and Group 2 included 42 subjects who received betahistine 48 mg/day for ten days with the Epley maneuver. Dizziness handicap inventory (DHI) and Beck anxiety inventory (BAI) were evaluated at the time of diagnosis and at the control examination on the tenth day.

Results

The mean before and after treatment DHI scores were 38.8 ± 14.6 and 5.47 ± 6.4 for Group 1 (P < 0.001), and 45.8 ± 21.1 and 10.3 ± 12.9 for Group 2 (P < 0.001). The mean before and after treatment BAI scores were 11.8 ± 6 and 1.33 ± 1.8 for Group 1 (P < 0.001), and 13.6 ± 8.3 and 2.9 ± 3.8 for Group 2 (P < 0.001). There was no significant difference between the before and after treatment DHI and BAI score differences of the two groups (P = 0.27, P = 0.43).

Conclusion

Canalith repositioning maneuvers (CRMs) should be the main treatment modality in the management of BPPV patients and adding on betahistine treatment to CRMs have no impact in the relieving of dizziness and anxiety symptoms.

Comparison of RPM (Re-positioning Maneuver) & Liberatory maneuvers vs Betahistine on BPPV (Benign Paroxysmal Positional Vertigo) for improving functional ability and quality of life

BPPV is a vestibular disease which arises due to positional changes of head. Objective: To compare the efficacy of CRP & Liberatory maneuvers collectively in contrast to Betahistine alone for improving quality of life oof BPPV patients. Methods: After getting the approval from ERC of RIHS (Rawal Institute of Health Sciences) Islamabad, this study was conducted at Rawal General & Dental Hospital Islamabad from 20th September 2022 to 19th Jan 2023. 30 patients between age of 20-50 years with first episode of vertigo were included in this study. Two groups were formulated. Group A patients were given CRP (Epley’s maneuver) & Liberatory maneuver (Semont’s) whereas group B patients were given just Betahistine 16mg. Both techniques were used twice a day for one week. Tools used for assessment were DHI & SF-36. SPSS version 21 was employed for analysis. Results: Mean+SD of age was 32.40+10.91 in group A and 29.93+11.67 in group B. The frequency of age between 20-30 years old patients was 07(46.4%) in group A and 11(73.7%) in group B. The frequency in age group 31-40 & 41-50 was 04(26.8%) & 04(26.8%) in group A whereas in group B it was 04(26.3%) & 0(0%) respectively. within group analysis of both groups showed significant improvement (p<0.05) on. Between groups Analysis revealed insignificant difference (p>0.05). Conclusion: Both maneuvers in combination are equally effective as Betahistine is in improving the quality of life of BPPV patients.

Efficacy of Epley's maneuver plus betahistine in the management of PC-BPPV: A systematic review and meta-analysis

BACKGROUND

To evaluate the efficacy of Epley's maneuver plus betahistine in the management of patients with posterior canal benign paroxysmal positional vertigo (PC-BPPV).

METHODS

Electronic databases including PubMed, Embase, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure, and Wanfang were searched from their inception to April, 2022. The effect size was analyzed by calculating the pooled risk ratio estimates of efficacy rate, recurrence rate, and standardized mean differences (SMD) of dizziness handicap inventory (DHI) score with a 95% confidence interval (CI). Sensitive analysis was performed simultaneously.

RESULTS

A total of 9 randomized controlled trials with 860 PC-BPPV patients were included in the meta-analysis, in which 432 were treated with Epley's maneuver plus betahistine, and 428 received Epley's maneuver alone. The meta-analysis revealed that Epley's maneuver plus betahistine significantly improved DHI score than Epley's maneuver alone (SMD = -0.61, 95% CI -0.96 to -0.26, P = .001). In addition, both Epley's maneuver plus betahistine and Epley's maneuver groups had comparable outcomes in efficacy rate and recurrence rate.

CONCLUSION

This meta-analysis shows that Epley's maneuver plus betahistine in PC-BPPV patients had favorable effects on DHI score.

Systemic pharmacological interventions for Ménière's disease

BACKGROUND

Ménière's disease is a condition that causes recurrent episodes of vertigo, associated with hearing loss and tinnitus. A number of pharmacological interventions have been used in the management of this condition, including betahistine, diuretics, antiviral medications and corticosteroids. The underlying cause of Ménière's disease is unknown, as is the way in which these treatments may work. The efficacy of these different interventions at preventing vertigo attacks, and their associated symptoms, is currently unclear.

OBJECTIVES

To evaluate the benefits and harms of systemic pharmacological interventions versus placebo or no treatment in people with Ménière's disease.

SEARCH METHODS

The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 14 September 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs in adults with definite or probable Ménière's disease comparing betahistine, diuretics, antihistamines, antivirals or systemic corticosteroids with either placebo or no treatment. We excluded studies with follow-up of less than three months, or with a cross-over design (unless data from the first phase of the study could be identified).  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were: 1) improvement in vertigo (assessed as a dichotomous outcome - improved or not improved), 2) change in vertigo (assessed as a continuous outcome, with a score on a numerical scale) and 3) serious adverse events. Our secondary outcomes were: 4) disease-specific health-related quality of life, 5) change in hearing, 6) change in tinnitus and 7) other adverse effects. We considered outcomes reported at three time points: 3 to < 6 months, 6 to ≤ 12 months and > 12 months. We used GRADE to assess the certainty of evidence for each outcome.  MAIN RESULTS: We included 10 studies with a total of 848 participants. The studies evaluated the following interventions: betahistine, diuretics, antivirals and corticosteroids. We did not identify any evidence on antihistamines.  Betahistine Seven RCTs (548 participants) addressed this comparison. However, we were unable to conduct any meta-analyses for our primary outcomes as not all outcomes were considered by every study, and studies that did report the same outcome used different time points for follow-up, or assessed the outcome using different methods. Therefore, we were unable to draw meaningful conclusions from the numerical results. Some data were available for each of our primary outcomes, but the evidence was low- or very low-certainty throughout. One study reported on the outcome 'improvement in vertigo' at 6 to ≤ 12 months, and another study reported this outcome at > 12 months. Four studies reported on the change in vertigo, but again all used different methods of assessment (vertigo frequency, or a global score of vertigo severity) or different time points. A single study reported on serious adverse events.  Diuretics Two RCTs addressed this comparison. One considered the use of isosorbide (220 participants), and the other used a combination of amiloride hydrochloride and hydrochlorothiazide (80 participants). Again, we were unable to conduct any meta-analyses for our primary outcomes, as only one study reported on the outcome 'improvement in vertigo' (at 6 to ≤ 12 months), one study reported on change in vertigo (at 3 to < 6 months) and neither study assessed serious adverse events. Therefore, we were unable to draw meaningful conclusions from the numerical results. The evidence was all very low-certainty.  Other pharmacological interventions We also identified one study that assessed antivirals (24 participants), and one study that assessed corticosteroids (16 participants). The evidence for these interventions was all very low-certainty. Again, serious adverse events were not considered by either study.

AUTHORS' CONCLUSIONS

The evidence for systemic pharmacological interventions for Ménière's disease is very uncertain. There are few RCTs that compare these interventions to placebo or no treatment, and the evidence that is currently available from these studies is of low or very low certainty. This means that we have very low confidence that the effects reported are accurate estimates of the true effect of these interventions. Consensus on the appropriate outcomes to measure in studies of Ménière's disease is needed (i.e. a core outcome set) in order to guide future studies in this area and enable meta-analyses of the results. This must include appropriate consideration of the potential harms of treatment, as well as the benefits.

Effects of Betahistine on Vestibulo-Ocular Reflex in Normal Healthy Adults: A Randomized Double-Blind, Placebo-Controlled Trial

Introduction

Vertigo, or the perception of a spinning sensation, is a common symptom experienced by patients who are referred to Otorhinolaryngology clinics. Betahistine is a medication that has been widely used to treat vertigo and its accompanying symptoms. However, the effects of this medication on the vestibulo-ocular reflex (VOR) are still unknown. Initially, it was assumed that betahistine should be discontinued prior to any vestibular tests, particularly the video head impulse test (vHIT).

Method

Thirty young healthy adults were randomly divided into two equal groups for this randomized double-blind clinical study (betahistine 24 mg and placebo). Baseline pure-tone audiometry (PTA), tympanometry, and VOR measurements were taken, followed by experimental measurements at one hour, four hours, eight hours, and 24 hours after consumption. The video head impulse test (vHIT) was used to determine the VOR.

Result

Betahistine had no statistically significant effect on vestibulo-ocular reflex gain (F(4,140) = 0.601, p = 0.662). The gain variability across repetitive head impulses remained constant over time.

Conclusions

Betahistine has no effect on the vestibulo-ocular reflex. As a result, this medication can be taken prior to the vHIT procedure.

Low Dose Betahistine in Combination With Selegiline Increases Cochlear Blood Flow in Guinea Pigs

OBJECTIVE

Betahistine is frequently used in the pharmacotherapy for Menière's Disease (MD). Little is known about its mode of action and prescribed dosages vary. While betahistine had an increasing effect on cochlear microcirculation in earlier studies, low dose betahistine of 0.01 mg/kg bw or less was not able to effect this. Selegiline inhibits monoaminooxidase B and therefore potentially the breakdown of betahistine. The goal of this study was to examine whether the addition of selegiline to low dose betahistine leads to increased cochlear blood flow.

METHODS

Twelve Dunkin-Hartley guinea pigs were anesthetized, the cochlea was exposed and a window opened to the stria vascularis. Blood plasma was visualized by injecting fluoresceinisothiocyanate-dextrane and vessel diameter and erythrocyte velocity were evaluated over 20 minutes. One group received low dose betahistine (0.01 mg/kg bw) and selegiline (1 mg/kg bw) i.v. while the other group received only selegiline (1 mg/kg bw) and saline (0.9% NaCl) as placebo i.v.

RESULTS

Cochlear microcirculation increased significantly (P < .001) in guinea pigs treated with low dose betahistine combined with selegiline by up to 58.3 ± 38.7% above baseline over a period of up to 11 minutes. In one guinea pig, the increase was 104.6%. Treatment with Selegiline alone did not affect microcirculation significantly.

CONCLUSIONS

Low dose betahistine increased cochlear microcirculation significantly when combined with selegiline. This should be investigated in further studies regarding dose-effect relation in comparison to betahistine alone. Side effects, in particular regarding circulation, should be considered carefully in view of the clinical applicability of a combination therapy in patients with MD.

Drug-Drug Interactions in Vestibular Diseases, Clinical Problems, and Medico-Legal Implications

Peripheral vestibular disease can be treated with several approaches (e.g., maneuvers, surgery, or medical approach). Comorbidity is common in elderly patients, so polytherapy is used, but it can generate the development of drug-drug interactions (DDIs) that play a role in both adverse drug reactions and reduced adherence. For this reason, they need a complex kind of approach, considering all their individual characteristics. Physicians must be able to prescribe and deprescribe drugs based on a solid knowledge of pharmacokinetics, pharmacodynamics, and clinical indications. Moreover, full information is required to reach a real therapeutic alliance, to improve the safety of care and reduce possible malpractice claims related to drug-drug interactions. In this review, using PubMed, Embase, and Cochrane library, we searched articles published until 30 August 2021, and described both pharmacokinetic and pharmacodynamic DDIs in patients with vestibular disorders, focusing the interest on their clinical implications and on risk management strategies.

Update on current diagnosis and treatment of vestibular neuritis

Vertigo is the sensation of self-motion of the head or body when no self-motion is occurring or the sensation of distorted self-motion during an otherwise normal head movement. Representative peripheral vertigo disorders include benign paroxysmal positional vertigo, Ménière disease, and vestibular neuritis. Vestibular neuritis, also known as vestibular neuronitis, is the third most common peripheral vestibular disorder after benign paroxysmal positional vertigo and Ménière disease. The cause of vestibular neuritis remains unclear. However, a viral infection of the vestibular nerve or ischemia of the anterior vestibular artery is known to cause vestibular neuritis. In addition, recent studies on immune-mediated mechanisms as the cause of vestibular neuritis have been reported. The characteristic clinical features of vestibular neuritis are abrupt true-whirling vertigo lasting for more than 24 hours, and no presence of cochlear symptoms and other neurological symptoms and signs. To accurately diagnose vestibular neuritis, various diagnostic tests such as the head impulse test, bithermal caloric test, and vestibular-evoked myogenic potential test are conducted. Various treatments for vestibular neuritis have been reported, which are largely divided into symptomatic therapy, specific drug therapy, and vestibular rehabilitation therapy. Symptomatic therapies include generalized supportive care and administration of vestibular suppressants and antiemetics. Specific drug therapies include steroid therapy, antiviral therapy, and vasodilator therapy. Vestibular rehabilitation therapies include generalized vestibular and customized vestibular exercises.

In Vitro Physiological Effects of Betahistine on Cell Lines of Various Origins

Objectives

Betahistine is a histamine analog commonly prescribed for symptomatic treatment of vertiginous symptoms. In vitro studies have shown that betahistine was not toxic at the prescribed doses in a nasal epithelial cell line. However, the effect of betahistine on other cell types has not been studied. In this study, we aimed to investigate some of the physiological effects of betahistine on L929 fibroblast, A549 lung cancer, human umbilical vein endothelial (HUVEC), and Ishikawa endometrial cell lines.

Materials and Methods

Cellular proliferation was assed assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, apoptosis was evaluated by acridine orange-ethidium bromide staining, and cellular migration was assed assessed by scratch assay.

Results

Betahistine treatment (0.1-0.5 mg/mL, 24 hours) can inhibit cell proliferation and induce apoptosis in HUVEC, A549, Ishikawa, and L929 cell lines. Betahistine (≥0.1 mg/mL) significantly increased the number of apoptotic cells (HUVEC: 26.3%, A549: 17.3%, L929: 8.6%, and Ishikawa: 2.3%). Betahistine at doses over 0.1 mg/mL significantly suppressed the cell migration rate in all of the cell lines. In contrast, exposure to a low dose of betahistine (0.025 mg/mL) induced migration rates of HUVEC and Ishikawa cells by 81% and 48%, respectively.

Conclusion

Betahistine may alter the processes of cellular proliferation, apoptosis, and cellular migration in a cell line- and dose-dependent manner. In this sense, proliferative and metastatic properties of certain cancer cells can potentially be altered in response to betahistine treatment.

Modulation of inner filter effect of non-conjugated silver nanoparticles on blue emitting ZnS quantum dots for the quantitation of betahistine

A simple, reliable and efficient fluorescent probe has been developed for the detection and quantitation of betahistine using inner filter effect (IFE) of silver nanoparticles (AgNPs) on zinc sulphide (ZnS) quantum dots. The synthesized ZnS exhibited blue emission at 403 nm which was quenched upon mixing with AgNPs due to intensive localized surface plasmon resonance (LSPR) absorption at 401 nm. The presence of IFE was confirmed by UV-Visible and fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. Addition of betahistine caused aggregation of AgNPs as visualized by the change in colour of nano-suspension. The reduced absorption at LSPR resulted in inhibition of IFE leading to higher fluorescence intensities in the presence of betahistine. Parameters such as pH, incubation time and concentration of AgNPs were suitably optimized. The fluorescence signal (I - I₀/I₀) responded linearly for betahistine in the concentration range from 0.1 to 10 μM under the optimized experimental conditions. Due to the aggregation of AgNPs, a simple colorimetric approach was also studied for quantitation of betahistine in the range 1.0-20 μM. The limit of detection for fluorescence measurement and colorimetric approach was 0.02 μM and 0.23 μM, respectively. Further, the proposed method exhibited excellent selectivity towards betahistine in presence of several cations, biomolecules such as glucose, uric acid, creatinine, amino acids and several anti-vertigo medications. The method was applied to quantify betahistine from pharmaceutical products and results obtained were in good agreement with the claimed values. The proposed sensor can serve a low cost, selective, sensitive and a precise tool for routine quantitation of betahistine.

Betahistine add-on therapy for treatment of subjects with posterior benign paroxysmal positional vertigo: a randomized controlled trial

Introduction

Benign paroxysmal positional vertigo is a common vestibular disorder that accounts for one fifth of hospital admissions due to vertigo, although it is commonly undiagnosed.

Objective

To evaluate the effects of betahistine add-on therapy in the treatment of subjects with posterior benign paroxysmal positional vertigo.

Methods

This randomized controlled study was conducted in a population of 100 subjects with posterior benign paroxysmal positional vertigo. Subjects were divided into the Epley maneuver + betahistine group (group A) and Epley maneuver only (group B) group. Subjects were evaluated before and 1-week after the maneuver using a visual analog scale and dizziness handicap inventory

Results

One hundred subjects completed the study protocol. The Epley maneuver had an overall success rate of 95% (96% in group A; 94% in group B, p =  0.024). Groups A and B had similar baseline visual analog scale scores (6.98 ± 2.133 and 6.27 ± 2.148, respectively, p = 0.100). After treatment, the visual analog scale score was significantly lower in both groups, and was significantly lower in group A than group B (0.74 ± 0.853 vs. 1.92 ± 1.288, respectively, p = 0.000). The change in visual analog scale score after treatment compared to baseline was also significantly greater in group A than group B (6.24 ± 2.01 vs. 4.34 ± 2.32, respectively, p = 0.000). The baseline dizziness handicap inventory values were also similar in groups A and B (55.60 ± 22.732 vs. 45.59 ± 17.049, respectively, p = 0.028). After treatment, they were significantly lower in both groups. The change in score after treatment compared to baseline was also significantly greater in group A than group B (52.44 ± 21.42 vs. 35.71 ± 13.51, respectively, p = 0.000).

Conclusion

The Epley maneuver is effective for treatment of benign paroxysmal positional vertigo. Betahistine add-on treatment in posterior benign paroxysmal positional vertigo resulted in improvements in both visual analog scale score and dizziness handicap inventory.

Clinical Practice Guideline: Ménière's Disease

OBJECTIVE

Ménière's disease (MD) is a clinical condition defined by spontaneous vertigo attacks (each lasting 20 minutes to 12 hours) with documented low- to midfrequency sensorineural hearing loss in the affected ear before, during, or after one of the episodes of vertigo. It also presents with fluctuating aural symptoms (hearing loss, tinnitus, or ear fullness) in the affected ear. The underlying etiology of MD is not completely clear, yet it has been associated with inner ear fluid (endolymph) volume increases, culminating in episodic ear symptoms (vertigo, fluctuating hearing loss, tinnitus, and aural fullness). Physical examination findings are often unremarkable, and audiometric testing may or may not show low- to midfrequency sensorineural hearing loss. Conventional imaging, if performed, is also typically normal. The goals of MD treatment are to prevent or reduce vertigo severity and frequency; relieve or prevent hearing loss, tinnitus, and aural fullness; and improve quality of life. Treatment approaches to MD are many and typically include modifications of lifestyle factors (eg, diet) and medical, surgical, or a combination of therapies.

PURPOSE

The primary purpose of this clinical practice guideline is to improve the quality of the diagnostic workup and treatment outcomes of MD. To achieve this purpose, the goals of this guideline are to use the best available published scientific and/or clinical evidence to enhance diagnostic accuracy and appropriate therapeutic interventions (medical and surgical) while reducing unindicated diagnostic testing and/or imaging.

The Impact of Betahistine versus Dimenhydrinate in the Resolution of Residual Dizziness in Patients with Benign Paroxysmal Positional Vertigo: A Randomized Clinical Trial

Objectives:

The aim of this study was to compare the effects of betahistine with dimenhydrinate on the resolution of residual dizziness (RD) of patients with benign paroxysmal positional vertigo (BPPV) after successful Epley maneuver.

Methods:

In this double-blind, randomized clinical trial, patients with posterior semicircular canal type of BPPV were included. After execution of the Epley maneuver, patients were assigned randomly to one group for 1 week: betahistine, dimenhydrinate or placebo. The primary outcomes were scores of the Dizziness Handicap Inventory (DHI) and the modified Berg balance scale (mBBS). All patients were asked to describe the characteristics of their subjective residual symptoms. Binary logistic regression analysis was performed to examine the predictors of improved RD. All analyses were conducted using SPSS 19.0.

Results:

In total, 117 patients (age range: 20-65 years) participated in this study. After the Epley maneuver, 88 participants had RD. After the intervention, 38 patients exhibited an improved RD. Less than 50% of participants in the three groups showed mild to moderate dizziness handicap. However, there was no significant difference between mBBS scores of groups before or after the intervention. Logistic regression was shown that patients with receiving betahistine were 3.18 times more likely to have no RD than the placebo group. Increasing age was associated with a decreased likelihood of improving RD ( P = .05).

Conclusion:

The analysis of data showed that the use of betahistine had more effect on improving RD symptoms. We recommended future studies using objective indicators of residual dizziness.

Pharmacokinetics and Dose Proportionality of Betahistine in Healthy Individuals

Betahistine dihydrochloride is widely used to reduce the severity and frequency of vertigo attacks associated with Ménière’s disease. Betahistine is an analogue of histamine, and is a weak histamine H1 receptor agonist and potent histamine H3 receptor antagonist. The recommended therapeutic dose for adults ranges from 24 to 48 mg given in doses divided throughout the day. Betahistine undergoes extensive first-pass metabolism to the major inactive metabolite 2-pyridyl acetic acid (2PAA), which can be considered a surrogate index for quantitation of the parent drug due to extremely low plasma levels of betahistine. The aim of the present investigation was to assess the pharmacokinetics and dose proportionality of betahistine in Arabic healthy adult male subjects under fasting conditions. A single dose of betahistine in the form of a 8, 16, or 24 mg tablet was administered to 36 subjects in randomized, cross-over, three-period, three-sequence design separated by a one week washout period between dosing. The pharmacokinetic parameters Cmax, AUC0–t, AUC0–∞, Tmax, and Thalf were calculated for each subject from concentrations of 2-PAA in plasma, applying non-compartmental analysis. The current study demonstrated that betahistine showed linear pharmacokinetics (dose proportionality) in an Arabic population over the investigated therapeutic dose range of 8–24 mg.

An Evaluation of the Effects of Betahistine and Dimenhydrinate on Posterior Canal Benign Paroxysmal Positional Vertigo

Objective

Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vestibular system disease causing dizziness. It occurs more in the 5th decade of life and affects the posterior canal in 90% of the patients. The most effective treatment method is canalith repositioning (CRP) maneuver. The aim of this study is to evaluate the effects of betahistine and dimenhydrinate therapies in addition to CRP maneuver on BPPV patients.

Methods

The study included 64 patients who had complaints of dizziness and were diagnosed with BPPV by their history and provocation maneuvers. The patients were divided into two groups. In Group 1, only repositioning maneuver was performed. Group 2 was divided into two subgroups. In Group 2a, repositioning maneuver was performed and betahistine 24 mg twice daily was given for 10 days. In Group 2b, repositioning maneuver was performed and dimenhydrinate 50 mg once daily was given for five days. On the 10^th day, all patients were reexamined, and provocation maneuver was performed. Dizziness handicap inventory (DHI) was completed and outcomes were reviewed for therapeutic efficacy.

Results

Mean DHI scores in all patient groups statistically significantly decreased from a pre-treatment level of 52.16 (range, 20-100) to a post-treatment level of 17.84 (range, 0-78) (p<0.001). No statistically significant differences were found in terms of DHI scores between Group 1 (repositioning maneuver only) and Group 2 (repositioning maneuver plus betahistine or dimenhydrinate).

Conclusion

The most effective treatment method of BPPV is repositioning maneuver. Addition of betahistine or dimenhydrinate pharmacotherapy to repositioning maneuver did not show superiority to treatment with repositioning maneuvers alone.

Management of peripheral vertigo with antihistamines: New options on the horizon

Vertigo is associated with a wide range of vestibular pathologies. It increasingly affects the elderly, with a high cost to society. Solutions include vestibular suppressants and vestibular rehabilitation, which form the mainstay of therapy. Antihistamines represent the largest class of agents used to combat vestibular vertigo symptoms. Agents targeting the H₁ and H₃ receptors have been in clinical use for several decades as single agents. Nonetheless, effective management of vertigo proves elusive as many treatments largely address only associated symptoms, and with questionable efficacy. Additionally, the primary and limiting side effect of sedation is counterproductive to normal functioning and the natural recovery process occurring via central compensation. To address these issues, the timing of administration of betahistine, the mainstay H₃ antihistamine, can be fine-tuned, while bioavailability is also being improved. Other approaches include antihistamine combination studies, devices, physical therapy and behavioural interventions. Recently demonstrated expression of H₄ receptors in the peripheral vestibular system represents a new potential drug target for treating vestibular disorders. A number of novel selective H₄ antagonists are active in vestibular models in vivo. The preclinical potential of SENS-111 (Seliforant), an oral first-in-class selective H₄ antagonist is the only such molecule to date to be translated into the clinical setting. With an excellent safety profile and notable absence of sedation, encouraging outcomes in an induced vertigo model in healthy volunteers have led to ongoing clinical studies in acute unilateral vestibulopathy, with the hope that H₄ antagonists will offer new effective therapeutic options to patients suffering from vertigo.

Advances in pharmacotherapy of vestibular and ocular motor disorders

INTRODUCTION

Vertigo and dizziness are common chief complaints of vestibular and ocular motor disorders (lifetime prevalence 30%). Treatment relies on physical, pharmacological, psychological and rarely surgical approaches. Eight groups of drugs are currently used in vestibular and ocular motor disorders, namely anti-vertiginous, anti-inflammatory, anti-menière's, anti-migrainous medications, anti-depressants, anti-convulsants, aminopyridines and agents that enhance vestibular plasticity.

AREAS COVERED

The purpose of this review is to summarize the pharmacological characteristics and clinical applications of medications that are used for peripheral, central and functional vestibular and ocular motor disorders. The level of evidence for the respective drugs is described alongside the pathophysiological premises supporting their use. The authors place particular focus on translation and back-translation in vestibular pharmacological research and the repurposing of known drugs for new indications and rare disorders.

EXPERT OPINION

The use of drugs in vestibular and ocular motor disorders is often based on open-label, non-controlled studies and expert opinion. In the future, strong evidence derived from RCTs is needed to support the effectiveness and tolerability of these therapies in well-defined vestibular and ocular motor disorders. Vestibular pharmacological research must be guided by a better understanding of the molecular targets relevant in the pathophysiology of vestibular and ocular motor disorders.

Histamine H1 Receptor Contributes to Vestibular Compensation

Vestibular compensation is responsible for the spontaneous recovery of postural, locomotor, and oculomotor dysfunctions in patients with peripheral vestibular lesion or posterior circulation stroke. Mechanism investigation of vestibular compensation is of great importance in both facilitating recovery of vestibular function and understanding the postlesion functional plasticity in the adult CNS. Here, we report that postsynaptic histamine H1 receptor contributes greatly to facilitating vestibular compensation. The expression of H1 receptor is restrictedly increased in the ipsilesional rather than contralesional GABAergic projection neurons in the medial vestibular nucleus (MVN), one of the most important centers for vestibular compensation, in unilateral labyrinthectomized male rats. Furthermore, H1 receptor mediates an asymmetric excitation of the commissural GABAergic but not glutamatergic neurons in the ipsilesional MVN, which may help to rebalance bilateral vestibular systems and promote vestibular compensation. Selective blockage of H1 receptor in the MVN significantly retards the recovery of both static and dynamic vestibular symptoms following unilateral labyrinthectomy, and remarkably attenuates the facilitation of betahistine, whose effect has traditionally been attributed to its antagonistic action on the presynaptic H3 receptor, on vestibular compensation. These results reveal a previously unknown role for histamine H1 receptor in vestibular compensation and amelioration of vestibular motor deficits, as well as an involvement of H1 receptor in potential therapeutic effects of betahistine. The findings provide not only a new insight into the postlesion neuronal circuit plasticity and functional recovery in the CNS, but also a novel potential therapeutic target for vestibular disorders.SIGNIFICANCE STATEMENT Vestibular disorders manifest postural imbalance, nystagmus, and vertigo. Vestibular compensation is critical for facilitating recovery from vestibular disorders, and of great importance in understanding the postlesion functional plasticity in the adult CNS. Here, we show that postsynaptic H1 receptor in the medial vestibular nucleus (MVN) contributes greatly to the recovery of both static and dynamic symptoms following unilateral vestibular lesion. H1 receptor selectively mediates the asymmetric activation of commissural inhibitory system in the ipsilesional MVN and actively promotes vestibular compensation. The findings provide not only a new insight into the postlesion neuronal circuit plasticity and functional recovery of CNS, but also a novel potential therapeutic target for promoting vestibular compensation and ameliorating vestibular disorders.

[The effectiveness of the intra-tympanic administration of methylprednisolone and gentamycin for the treatment of Meniere's disease]

Meniere's disease is an inner ear pathology characterized by periodic fits of systemic dizziness, fluctuating low-frequency sensorineural loss of hearing, stuffiness in the ear and tympanophonia. The objective of the present study was to evaluate the effectiveness of the intra-tympanic administration of methyl prednisolone in the combination with gentamycin used to treat the patients presenting with Meniere's disease. The study included 18 patients at the age varying from 18 to 70 years presenting with this condition. Group 1 was formed to treat the patients with gentamycin, group 2 was comprised of the patients treated with methyl prednisolone. Special emphasis was placed on the recording of dynamics of the parameters of tonal threshold audiometry and cervical evoked vestibular myogenic potentials. The episodes of dizziness were characterized based on the results of comparison of the number of systemic dizziness episodes within the first 6 months after the first injection of methyl prednisolone or gentamycin with the number of such episodes during one month prior to the onset of the treatment. The results were estimated based on the Dizziness Handicap Inventory (DHI scale). It was shown that the patients comprising group 2 experienced a more pronounced reduction in the number of dizziness episodes compared with those in group 1 (91.56 and 69.81% decrease respectively). Moreover, hearing improved by 35% in the patients of group 2, whereas the improvement was altogether absent the patients of group 1. The patients of both groups reported comparable reduction of subjective tympanophonia estimated based on the DHI scale. The results of the comparison were evaluated based on the DHI scale (54.9% in group 2 and 53.8% in group 1).

A Comparison of the Effects and Side Effects of Oral Betahistine with Injectable Promethazine in the Treatment of Acute Peripheral Vertigo in Emergency

Background

Vertigo is an illusion of rotation that is caused by the asymmetry of neurological function of the right and left vestibular nuclei. The aim of this study was to compare the efficacy and side effects of oral betahistine with injectable promethazine in treatment of acute peripheral vertigo.

Methods

In this double-blind clinical trial study, the patients with acute peripheral vertigo were assigned in the two groups: receiving promethazine intramuscularly at a dose of 25 mg (group A) and receiving 8 mg betahistine tablets (group B) and the severity of their vertigo was evaluated on the visual analog scale (VAS) scoring system. In addition, adverse events in both groups of patients were compared and evaluated.

Results

A total of 162 patients (82 subjects in group A) participated in this study. The mean age, gender distribution, intensity and symptoms of vertigo were similar in both groups before the intervention. At 2 and 3 h after the intervention, the score of VAS in patients taking betahistine was significantly higher than promethazine. In addition, the clinical symptoms after taking betahistine were significantly less. Side effects seen in patients taking the promethazine include mainly drowsiness. After taking betahistine, the most common complication was abdominal problems (nausea and vomiting).

Conclusion

The results of this study show that betahistine is a safe and effective drug in controlling patients with acute vertigo and its impact is more than promethazine.

Pharmacological modulators of autophagy activate a parallel noncanonical pathway driving unconventional LC3 lipidation

The modulation of canonical macroautophagy/autophagy for therapeutic benefit is an emerging strategy of medical and pharmaceutical interest. Many drugs act to inhibit autophagic flux by targeting lysosome function, while others were developed to activate the pathway. Here, we report the surprising finding that many therapeutically relevant autophagy modulators with lysosomotropic and ionophore properties, classified as inhibitors of canonical autophagy, are also capable of activating a parallel noncanonical autophagy pathway that drives MAP1LC3/LC3 lipidation on endolysosomal membranes. Further, we provide the first evidence supporting drug-induced noncanonical autophagy in vivo using the local anesthetic lidocaine and human skin biopsies. In addition, we find that several published inducers of autophagy and mitophagy are also potent activators of noncanonical autophagy. Together, our data raise important issues regarding the interpretation of LC3 lipidation data and the use of autophagy modulators, and highlight the need for a greater understanding of the functional consequences of noncanonical autophagy.

An LC-MS/MS assay for the quantitative determination of 2-pyridyl acetic acid, a major metabolite and key surrogate for betahistine, using low-volume human K2 EDTA plasma

Betahistine is widely used for the treatment of vertigo. Owing to first-pass metabolism, 2-pyridyl acetic acid (2PAA, major metabolite of betahistine) was considered as surrogate for quantitation. A specific and sensitive LC-MS/MS method was developed and validated for quantitation of 2PAA using turbo-ion spray in a positive ion mode. A solid-phase extraction was employed for the extraction of 2PAA and 2PAA d₆ (IS) from human plasma. Chromatographic separation of analytes was achieved using an ACE CN, 5 μm (50 × 4.6 mm) column with a gradient mobile phase comprising acetonitrile-methanol (90:10% v/v) and 0.7% v/v formic acid in 0.5 mm ammonium trifluoroacetate in purified water (100% v/v). The retention times of 1.15 and 1.17 min for 2PAA and internal standard, respectively, were achieved. Quantitation of 2PAA and internal standard was achieved by monitoring multiple reaction monitoring transition pairs (m/z 138.1 to m/z 92.0 and m/z 142.1 to m/z 96.1, respectively). The developed method was validated for various parameters. The calibration curves of 2PAA showed linearity from 5.0 to 1500 ng/mL, with a lower limit of quantitation of 5.0 ng/mL. The bias and precision for inter- and intra-batch assays were <10%. The developed method was used to support clinical sample analysis.