Betahistine Research Articles

Betahistine's Neuroprotective Actions against Lipopolysaccharide-Induced Neurotoxicity: Insights from Experimental and Computational Studies.

Histamine H3 receptor (H3R) antagonists, such as betahistine (BHTE), have shown significant potential in treating central nervous system (CNS) disorders due to their neuroprotective properties. This study investigated BHTE's effects on lipopolysaccharide (LPS)-induced neurotoxicity, which is associated with neuroinflammation and neurodegeneration. Rats were divided into groups and pre-treated with BHTE (5 or 10 mg/kg, p.o.) for 30 days, followed by LPS administration (1 mg/kg, i.p.) for 4 consecutive days to induce neurotoxicity. LPS exposure resulted in cognitive impairment, as evidenced by performance deficits in maze tests, and a significant reduction in brain acetylcholine (ACh) levels. Additionally, LPS led to increased neuroinflammation, oxidative stress, mitochondrial dysfunction, and apoptosis. Pre-treatment with BHTE effectively counteracted these effects, improving cognitive performance and restoring ACh levels. BHTE significantly reduced LPS-induced increases in pro-inflammatory markers (COX-2, TNF-α, and IL-6) while enhancing anti-inflammatory cytokines (IL-10 and TGF-β1). Furthermore, BHTE improved mitochondrial function by increasing enzyme levels (MRCC-I, II, and IV) and boosted anti-apoptotic (Bcl-2) and antioxidant defenses (GSH and catalase). BHTE also reduced apoptosis markers, including pro-apoptotic protein caspase-3, and oxidative stress marker malondialdehyde (MDA). Molecular modeling studies revealed that BHTE effectively binds to key enzymes involved in neuroinflammation and apoptosis (AChE, COX-2, and caspase-3), with binding free energies between 4 and 5 kcal/mol, interacting with critical residues. These findings underscore BHTE's multifaceted neuroprotective effects against LPS-induced neurotoxicity, offering potential therapeutic avenues for managing neuroinflammation and related neurodegenerative disorders.

Innovative Formulation and Evaluation of Betahistine Floating Tablets for Vertigo Management

Floating tablets are designed to improve the effectiveness and consistency of medication delivery. These specializedoral drug delivery systems are engineered to float on the gastric fluid in the stomach for an extended period, ensuring prolongedgastric retention that leads to a slow and controlled drug release, ultimately enhancing its bioavailability and therapeutic efficacy.Meniere's disease comprises recurrent spontaneous rotatory vertigo spells that patients describe as a spinning or whirling feelingand sensorineural hearing loss (SNHL) accompanied by recruitment and tinnitus. This study aimed to create buoyant tabletscontaining Betahistine (BTH) for treating Meniere's disease, designed to float in fluids and discharge the drug gradually. Theapproach involved the utilization of HPMC K4M 100 and Chitosan in combination as agents for swelling. Gas generation wasfacilitated by sodium bicarbonate and citric acid, while lactose was incorporated as a bulking agent. Tablets were fabricated usingthe direct compression technique and subjected to various assessments, including thickness, hardness, weight consistency,friability, BTH content, swelling capacity, buoyancy, and BTH release patterns. Notably, FTIR analyses indicated the absence ofsignificant interactions between the BTH and its constituents. This comprehensive strategy underscores the potential of thesetablets as a reliable and enduring treatment choice for Meniere's disease. Among nine formulations, F5 displayed the least BTHdischarge (73.47±1.27% over 12 h), while F2 demonstrated the highest discharge (85.92±2.36% over 12 h). These findingshighlight formulation F5's potential for controlled BTH discharge, which could be beneficial in managing Meniere's diseasesymptoms. This thorough investigation contributes to optimizing the formulation to treat Meniere's disease with buoyant tabletsincorporating Betahistine efficiently.

Eco-Friendly and Sensitive HPLC and TLC Methods Validated for the Determination of Betahistine in the Presence of Its Process-Related Impurity

Reducing the amounts consumed of organic solvents while keeping good chromatographic performance has been a significant step towards the greening of analytical methodologies. When sodium dodecyl sulfate (SDS) and Brij-35 surfactants are combined in a mobile phase, they can be used as a green alternative to organic modifiers. Surfactants have numerous advantages, including low cost and toxicity, safe environmental disposal, and unique selectivity, in addition to high solubilization capabilities. In this research, two highly selective chromatographic methods were adopted for the determination of betahistine (BHS) in the presence of its pharmacopeial impurity 2-(2-hydroxyethyl)pyridine (HEP). A solvent-free HPLC method was validated, in which the mixture was separated using a C18 column (3.5 µm, 75.0 × 4.6 mm) and a mobile phase composed of 0.01 M Brij-35, 0.12 M SDS, and 0.02 M disodium hydrogen phosphate adjusted to a pH of 5.5 using phosphoric acid. The flow rate was 1.5 mL min−1 and the resolved peaks were detected at 260 nm. Another HPTLC-densitometric method was validated using HPTLC aluminum plates coated with silica gel 60 F254 as the stationary phase and a developing system consisting of methylene chloride/methanol/ethyl acetate/ammonia (at a ratio of 5:2:2:0.2 by volume); the separated bands were scanned at 260 nm.

Betahistine for Ménière's disease or syndrome

Betahistine for Ménière's disease or syndrome

Assessment of Transdermal Vasodilatatory Effect of a Combined Panthenol, Amlodipine, Isosorbide Dinitrate and Betahistine HCl on Peripheral Vessels

Peripheral vascular diseases are group of disorders characterized by stenozing peripheral circulation as a complication of primary disease like diabetes mellitus. Peripheral vascular diseases affect 202 million around the world. Peripheral vascular complications of diabetes mellitus are common which affect 30 million over the world and may give rise to infectious necrotizing sequalae called diabetic foot. In a trial of assessment for transdermally applied vasodilator drugs, 30 individual had participated in a case controlled study. Test group (N =11) and control group (N =19) were assessed for the signs of vasodilatation over the dorsum of the hand and figure blood perfusion detection. There was significant increase in perfusion index (from 7 to 11) induced by the test vasodilator as compared with control (from 7 to 8) P <0.05 and parallel results were obtained in induction of redness (redness ratio of 7 with C.I. over 0.95 and thermal increase in degrees of ( C ) over the dorsum of the hand in comparison with the control group. From the overall results the combined vasodilatatory transdermal formula caused a significant peripheral vasodilatation which could be a candidate therapeutic effect in diabetic foot

Efficacy and safety of Carbamazepine in treatment of vestibular complications

Objective To evaluate the efficacy and safety of Carbamazepin(CBZ)compared with Oxcarbazepine(OXC)therapy for vestibular paroxysmia. Methods Eighty-two patients with vestibular paroxysmia were admitted during June 2013 and June 2017 in this study.According to the agents administered, all patients were divided into the CBZ group(n=31), CBZ+ Betahistine(BMT)group(n=26)and OXC+ BMT group(n=25). The clinical efficacy, frequency, vertigo and adverse reactions of three groups were compared after 3 months follow-up. Results In CBZ group, 14 cases were cured, 13 were improved, and the effective rate was 87.1%.In CBZ+ BMT group, 18 cases were cured, 7 were recovered, and the effective rate was 96.2%.In OXC+ BMT group, 15 cases were cured, 8 cases were recovered, and the effective rate was 92.0%.There was no significantly difference in effective rate among the three groups(χ2=0.783, P=0.129). Meanwhile, the CBZ+ BMT group had the lowest frequency of vestibular paroxysmia and vertigo degree, while the CBZ group was the highest; the difference in the frequency and vertigo degree between groups was statistically significant(P<0.05). Furthermore, the incidences of side-effects were 51.6%(n=16), 30.8%(n=8)and 16.0%(n=4)in the CBZ group, CBZ+ BMT group and OXC+ BMT group, respectively. Conclusions The effect of Carbamazepine and Oxcarbazepine for vestibular paroxysmia is similar, and is safely and significantly improved when combined with Betahistine. Key words: Carbamazepine; Betahistine; Vestibular diseases

Betahistine dihydrochloride quantitative determination in dosage forms by the reaction with sodium 1,2-napthoquinone-4-sulphonate

Спектрофотометричний метод – один із найбільш зручних методів у фармацевтичному аналізі, оскільки він чутливий, точний та економічний. Мета роботи – розробка простої та доступної методики кількісного визначення бетагістину дигідрохлориду в лікарських формах. Матеріали та методи. Натрієву сіль 1,2-нафтохінон-4-сульфокислоти оцінювали як хімічний реагент для кількісного спектрофотометричного визначення бетагістину дигідрохлориду. Результати. Різноманітні чинники, що впливають на взаємодію між натрієвою сіллю 1,2-нафтохінон-4-сульфокислоти та лікарською речовиною, ретельно вивчені, оптимізовані. Встановили, що бетагістину дигідрохлорид реагує з натрієвою сіллю 1,2-нафтохінон-4-сульфокислоти в лужному середовищі з утворенням забарвленого продукту реакції з максимумом абсорбції при 485 нм. Виконали валідацію розробленої методики. Перевірили основні валідаційні характеристики: лінійність, прецизійність, правильність, робастність і діапазон застосування. Підпорядкування закону Бера спостерігають у межах концентрації 2,40–4,00 мг/100 мл. Параметри лінійної залежності розрахували за допомогою регресійного аналізу методом найменших квадратів. Визначили коефіцієнти стехіометричних співвідношень методами молярних співвідношень і неперервних змін. Запропонована методика відповідає вимогам ДФУ, що ставлять до методик кількісного аналізу лікарських речовин. Висновки . На основі досліджень розроблено та валідовано спектрофотометричну методику кількісного визначення бетагістину дигідрохлориду, котру успішно застосували для аналізу лікарських форм. Результати дослідження свідчать, що методика є високочутливою, точною, простою у виконанні та придатною для використання в лабораторіях контролю якості лікарських речовин.

Betahistine for Ménière's disease or syndrome

Betahistine for Ménière's disease or syndrome

Effect of modified Buyang Huanwu decoction combined with betahistine hydrochloride in the treatment of vertebral-basilar artery ischemic vertigo and its influence on hemorheological index

Objective To observe the therapeutic effect of modified Buyang Huanwu decoction combined with betahistine hydrochloride in the treatment of vertebral-basilar artery ischemic vertigo and its influence on hemorheological index. Methods 80 patients with vertebral-basilar artery ischemic vertigo were randomly divided into observation group and control group, 40 cases in each group. The control group was given betahistine hydrochloride 12 mg, three times a day. The observation group was given modified Buyang Huanwu decoction on the basis of the control group, 4 weeks for a course. The DARS and DHI were measured before and after 4 weeks of treatment. The blood flow velocity was detected by transcranial Doppler ultrasonography, the difference of clinical curative effect between the two groups was compared. Results After treatment, the DARS and DHI scores of the observation group and control group were significantly decreased(t=14.716 and 5.258, 20.662 and 14.609, all P<0.01). The DARS and DHI scores in the observation group were significantly lower than those in the control group (t=3.644, 7.116, all P<0.05). After treatment, the average blood flow velocity of the vertebral artery, right vertebral artery and basilar artery in the observation group and the control group were significantly increased(t=11.216 and 7.447, 10.103 and 7.204, 11.303 and 6.642, all P<0.01). The average blood flow velocity of the vertebral artery, right vertebral artery and basilar artery in the observation group were significantly higher than those of the control group (t=4.405, 4.761, 5.824, all P<0.01). The total effective rate of the observation group was 95.00% (38/40), which was significantly higher than that of the control group (77.50%, 31/40), the difference was statistically significant (Z=-2.000, P<0.05). Conclusion Modified Buyang Huanwu decoction combined with betahistine hydrochloride is effective in the treatment of vertebro-basilar ischemic vertigo. It can improve the blood supply to the brain and relieve the symptoms of vertigo, which is worthy of popularization and application. Key words: Vertebrobasilar insufficiency; Modified buyang huanwu decoction

Evaluation of anti anxiety treatment in residual dizziness after successful canalith repositioning procedure in benign paroxysmal positional vertigo

Objective To study the effect of anti anxiety treatment in residual dizziness after successful canalith repositioning procedure in benign paroxysmal positional vertigo. Methods 68 cases of benign paroxysmal position vertigo patients with residual dizziness after successful canalith repositioning procedure were collected, who visit department of Neurology..They were randomly assigned to anti anxiety group and the control group according to randomized controlled method.Deanxit (0.5mg/10mg, 1times/day) combined with betahistine mesilate tablets (6mg, 3 times/day) were taken by patients in the anti anxiety group; take betahistine mesilate tablets (6mg, 3 times/day) were taken in the control group.Follow up 3 months, the duration of residual dizziness and the changes of symptoms between the two groups were compared.The symptoms of all patients were evaluated before and after treatment by dizziness handicap inventory. Results The duration of residual dizziness in the control group was (16.38±8.83)days, and that in the anti anxiety group was (10.13±5.10)days.The duration of residual dizziness in the anti anxiety group was significantly shorter than that in the control group (t=3.440, P 0.05) in the treatment of first week.In second week and third week, the scores of the anti anxiety group were lower than those of the control group, the differences were statistically significant (t=3.378, 4.935, all P<0.05). After 3 weeks of treatment, the scores of the anti anxiety group were significantly decreased in the functional, emotional and physical scores (t=5.297, 4.537, 4.451, all P<0.01). Conclusion Deanxit can shorten residual dizziness duration of benign paroxysmal position vertigo patients after successful canalith repositioning procedure, and can reduce the degree of residual dizziness. Key words: Vertigo; Otolithic membrane; Deanxit

Clinical research of Yangxue-Qingnao granules on posterior circulation of ischemia

Objective To evaluate the curative effect and security of Yangxue-Qingnao granules on posterior circulation ischemia. Methods 52 patients with posterior circulation ischemia from September 2012 to January 2014 in Remin hospital of Wuhan Universityk, were randomly recruited into a control group and a treatment group, with 26 cases in each group. The control group was only treated with flunarizine HCL and Betahistine Mesilate Tablets, while the treatment group was given Yangxue-Qingnao granules based on the control group. The change of clinical symptoms, TCD and cervical vascular ultrasound were observed before and after the treatment. Results After the treatment, the total effective rate of treatment group was significantly different to the control group (96.2% vs. 76.9%; χ2=4.127, P=0.042). The changes of blood flow velocity of vertebral artery, basilar artery and posterior inferior cerebellar artery were all decreased after the treatment in both groups ( t value in the treatment group were 20.624, 13.773, and 9.485 respectively，t value in the control group were 13.203, 9.550, and 5.655, respectively, all P<0.01）, besides such decreases in the treatment group were better than the control group (all P<0.01）. After the treatment, the condition of carotid IMT decrease was significantly better in the treatment group than the control group (the number rate of IMT decrease was (96.2% vs. 69.2%; χ2=5.318, P=0.021). Conclusion Yangxue-Qingnao granules can obviously improve the blood flow velocity and the thickness of IMT in patients with posterior circulation ischemia. The short-term curative effect is obvious. Key words: Brain ischemia; Vertebrobasilar insufficiency; Yangxue-Qingnao granules

Influence of betahistine on the expression of histamine H3 receptor in the medial vestibular nucleus following unilateral labyrinthectomy in guinea pigs

To observe the influence of betahistine on the expression of histamine H3 receptor in the medial vestibular nucleus (MVN) following unilateral labyrinthectomy (UL). Fifty-six healthy guinea pigs were randomly divided into three groups:the sham-operated group (group I), the UL group[group II, and UL+betahistine (BET) group (group III)], BET was intraperitoneally injection at 2.17 mg×kg(-1)×d(-1) for 7 days. The expression of histamine H3 receptor was analyzed by immunohistochemistry at 1 day, 3 days and 7 days after UL. H3 receptors were presented in the MVN and the expression of histamine H3 receptor were increased significantly in the ipsilateral MVN at 1 and 3 days after UL(P < 0.05), the change turned into the normal value at 7 days(P > 0.05). In the UL+BET group, the intensity of histamine H3 receptor was lower than that in the UL at 1 day and 3 days(4.25 ± 0.71, 3.50 ± 0.92 vs 5.75 ± 0.71, 5.50 ± 0.93, P < 0.05). However, the changes turned into the normal values at 3 and 7 days (P > 0.05). The early stage of the vestibular compensation process may be associated with the change of H3 receptor expression in MVN. In the UL+BET group the histamine H3 receptor recovered quickly.

Modified Epley maneuver associated with betahistine for treating posterior semicircular canal benign paroxysmal positional vertigo

Objective To analyze the efficacy of modified epley maneuver associated with betahistine for treating posterior semicircular canal benign paroxysmal positional vertigo(PC-BPPV).Methods 78 cases with unilateral PC-BPPV were divided into complexed therapy group(39 cases)and control group(39 cases)randomly.The complexed therapy group was treated by modified epley maneuver associated with betahistine 6mg per time,3 times daily for successive 1 month.the control group was treated by modified epley maneuver only.Results 78 patients after first treatment,56 cases were cured,control group(28 patients),complexed therapy group(28 cases),no statistically significant difference between the two groups.After 1 month of treatment,the control group were cured 30 cases,effective 3 cases,invalid 6 cases;the complexed therapy group were cured 37 cases,effective 1 case,invalid 1 case;complexed therapy group,the cure rate was 94.9％,significantly higher than the 76.9％ of control group(x2=4.3365,P＜0.05).Conclusion The modified epley maneuver associated with betahistine is effective to treat PCBPPV,which is worth being promoted. Key words: Vertigo; Modified epley maneuver associated; Betahistine

Development and evaluation of sustained release tablet of betahistine hydrochloride using ion exchange resin tulsion t344.

An attempt was made to sustain the release of Betahistine hydrochloride by complexation technique using strong cation-exchange resin, Tulsion T344. The drug loading onto ion-exchange resin was optimized for mixing time, activation, effect of pH, swelling time, ratio of drug : resin, and temperature. The resinate was evaluated for micromeritic properties and characterized using XRPD and IR. For resinate sustained release tablets were formulated using hydoxypropyl methylcellulose K100M. The tablets were evaluated for hardness, thickness, friability, drug content, weight variation, and in vitro drug release. Tablets thus formulated (Batch T-3) provided sustained release of drug over a period of 12 h. The release of Betahistine HCl from resinate controls the diffusion of drug molecules through the polymeric material into aqueous medium. Results showed that Betahistine HCl was formulated into a sustained dosage form as an alternative to the conventional tablet.

Comprehensive treatment for degenerative instability of lower cervical spine and cervical vertigo

Objective To explore the relationship between cervical spine instability and cervical vertigo by analyzing the efficacy of therapies for degenerative instability of lower cervical spine and cervical vertigo.Methods The data on 64 with degenerative instability of lower cervical spine and cervical vertigo were retrospectively analyzed.All the patients were randomly assigned to receive intravenous Shengmai injection,Honghua injection,and oral betahistine Hydrochloride solution ( group A )or bedside cervical traction in addition to the therapies in the group A ( group B ).The patients without ideal efficacy received surgical treatment.The changes in vertebral artery blood flow were detected and the efficacy was assessed.Results As compared with the baseline, vertebral artery blood flow did not change significantly after treatment ( P＞ 0.05 ).Group B was superior to group A in the effectiveness rate ( 81.25％ vs.56.25％,P ＜ 0.05 ).Conclusions Cervical spine instability is one of the important causes of cervical vertigo.Maintenance of cervical spine stability is an important method for the treatment of degenerative instability of lower cervical spine and cervical vertigo. Key words: Cervical spine instability; Cervical vertigo; Reconstruction stability

Development and &lt;i&gt;In vitro&lt;/i&gt; Evaluation of Betahistine Adhesive-Type Transdermal Delivery System

Purpose: To develop a transdermal betahistine (BTH) delivery system using different pressure sensitive adhesives (PSAs) including acrylics, polyisobutylene and styrenic rubber solution.Methods: Formulations were prepared by solvent casting and adhesive transfer method. PSAs - acrylate vinylacetate (AVA), hydrophilic acrylate (HA), acrylic non-curing (ANC), polyisobutylene (PIB), and tackified styrenic rubber solution (TSR) - were evaluated for their suitability in terms of miscibility, maximum drug loading, effect on tack property and in vitro permeation through excised guinea pig skin. Furthermore, one of the PSAs was tested in relation to effect of penetration enhancers on tack property, in vitro permeation, in vivo patch adhesion performance and stability.Results: Only formulations prepared with AVA and HA were stable. Increased drug loading in these PSAs significantly reduced tack. In vitro permeation data across guinea pig skin demonstrated that BTH flux from from the formulation containing HA (F1) was significantly (p < 0.001) higher than that containing AVA (F2). Formulations containing 2 % enhancer showed good tack. Specifically, the formulation containing 2 % oleic acid as enhancer not only showed the highest permeation but also good tack property, non-irritancy for up to 36 h and stability under accelerated conditions.Conclusion: The formulation containing HA as the PSA and 2 % oleic acid as enhancer demonstrated a good potential for further development to an adhesive-type transdermal delivery system for BTH.Keywords: Meniere’s syndrome, Transdermal delivery, Betahistine, Pressure-sensitive adhesives, Penetration enhancersTropical Journal of Pharmaceutical Research December 2010; 9 (6): 516-524

Therapeutic Observation of betahistine injection combined with buflomedil injection in VBI treatment

Objective To investigate the therapeutic effects and safety of buflomedil injection and buflomedil injection on the patients with VBI. Methods The VBI patients were divided into two groups randomly: the treatment group ( n=118) and the control group ( n= 109 ). The patients in the treatment group got intravenous drips of binjeetion and buflomedil injection. The patients in the control group received intravenous drip of gastrodin injection. The changes in the clinical therapeutic were observed, such as hemorheology and hemodynamics of the groups be fore and after the treatment. Results Therapeutic outcome of the treatment group was obviously better than that. of the control group in improving patients symptom , hemorheology and hemodynamics with the cure rate 96.6% vs 77.1%, which was really significant (P<0.05). Conclususion The treatment group with betahistine injection combined with buflomedil injection has quicker, stronger and better effect and was reliably safe. Key words: Betahistine injection and buflomedil injection; VBL; Therapeutic effects

Efficacy of Trimezidine combined with betahistine on treating vertigo

Objectives To obsever the efficacy of trimetazidine combined with betahistine on treating vertigo. Methods 176 outpatients of vertigo were randomly divided into two groups. All patients were given the same treatment with energy mixture solutrol and anisodamine 10 mg. 88 patients in treatment group were given trimezidine combined with betahistine take orally. 88 patients in control group were given Fufang Danshen injection 20 ml combined with diazepam 10 mg, Therapeutic effects were compared between two groups. Results The cure rate(80.7%) and total effective rate(95,5%)were much higher in treatment group than the cure rate (59.1) and total effective rate (83%) in control group (P< 0.01).Conclusion Combination of trimetazidine and betahistine is a good method in treating vertigo. Key words: Trimetazidine; Betahistine; Vertigo; Drug therapy

Stress degradation studies on betahistine and development of a validated stability-indicating assay method

The purpose of this work was to study the stability of betahistine (BET) at different stress conditions and to develop a sensitive stability-indicating high-performance liquid chromatographic (HPLC) assay method. The stress conditions applied were including the effect of heat, moisture, acid–base, and ultra-violet (UV) light. Betahistine and its decomposition products were derivatized by reaction with dansyl chloride (Dan-Cl) and analyzed by HPLC equipped with fluorescence detector (FL) set at 336 and 531 nm as excitation and emission wavelengths, respectively. The drug was particularly labile at UV light and oxygen rich media. Two potential degradation products could be separated and identified by spectral methods. The chromatographic method involved Zorbax Eclipse XDB-C 18 column kept at 30 ± 2 °C and a gradient elution with mobile phase composed of acetonitrile and 0.02 mol L −1 sodium acetate. The response factor of dansylated BET monitored by fluorescence detection was 32 times more than its UV response. The calibration curve of BET in bulk form was linear from 0.005 to 4.2 ng μL −1. Intraday and interday precision were less than 0.04% (CV), and accuracy was between 99.2% and 100.9% over 2.0 ng μL −1. The limit of detection was 0.002 ng μL −1. The method was also validated for sample stability during reaction, robustness and selectivity. The method was applied for purity testing of betahistine in tablet form.

Histamine (H 3) receptors modulate the excitatory amino acid receptor response of the vestibular afferents

Although the effectiveness of histamine-related drugs in the treatment of peripheral and central vestibular disorders may be explained by their action on the vestibular nuclei, it has also been shown that antivertigo effects can take place at the peripheral level. In this work, we examined the actions of H 3 histaminergic agonists and antagonists on the afferent neuron electrical discharge in the isolated inner ear of the axolotl. Our results indicate that H 3 antagonists such as thioperamide, clobenpropit, and betahistine (BH) decreased the electrical discharge of afferent neurons by interfering with the postsynaptic response to excitatory amino acid agonists. These results lend further support to the idea that the antivertigo action of histamine-related drugs may be caused, at least in part, by a decrease in the sensory input from the vestibular endorgans. The present data show that the inhibitory action of the afferent neurons discharge previously described for BH is not restricted to this molecule but is also shared by other H 3 antagonists.