Betahistine Increases Vestibular Blood Flow

Abstract

Betahistine is used for treatment of several vestibular disorders. Despite the accepted use of this histamine-like substance, its mechanism of action is not well understood. The purpose of this study was to assess the possibility that one of the activities of betahistine is increasing blood flow in the peripheral vestibular end organs. Using a novel surgical approach, we identified the posterior semicircular canal ampulla of guinea pigs and placed a laser Doppler probe in position to obtain blood flow measurements from the posterior semicircular canal ampulla. Blood pressure, heart rate, and vestibular blood flow were continuously recorded. Concentration-response curves were obtained for betahistine (2.5, 5, 7.5, and 10 mg/kg) and control-vehicle (0.15 mol/L NaCl) infusions. A separate group of subjects was pretreated with the competitive selective H3 agonist, thioperimide maleate, before betahistine treatment. Increases in vestibular blood flow and decreases in blood pressure were observed in response to betahistine infusions. Pretreatment with thioperamide maleate abolished these changes at low doses of betahistine and attenuated the responses at higher doses of betahistine. These results show that betahistine administration induces increases in vestibular blood flow. These findings support the potential use of betahistine for treatment of vestibular disorders, which may be caused by compromised circulation.

Otimizando o componente farmacológico da terapia integrada da vertigem

“…It has been established that betahistine 8,[17][18][19] , cinnarizine [23][24] , clonazepam 8,11 , flunarizine [23][24] , or EGb 761 8,27-28 ameliorate vestibular vertigo. In the treatment of Ménière's diseases, betahistine proved eficatious8,31 and is more efficient than cinnarizine in reducing instability after vestibular neurectomy and in increasing vestibular compensation efficiency.…”

“…[12][13][14] EGb 761 accelerates postural and locomotor balance and oculomotor function recovery. 15 Betahistine is an H 3 heteroreceptor antagonist and an H1 receptor agonist [16][17] able to improve inner ear microcirculation. 17 It is used in the treatment of numerous vestibulopathies .…”

“…15 Betahistine is an H 3 heteroreceptor antagonist and an H1 receptor agonist [16][17] able to improve inner ear microcirculation. 17 It is used in the treatment of numerous vestibulopathies . 8,[17][18][19] There may be side effects such as headaches and epigastric discomfort; gastrointestinal ulcers, asthma and pheochromocytoma are counter-indications to the use of this drug.…”

“…17 It is used in the treatment of numerous vestibulopathies . 8,[17][18][19] There may be side effects such as headaches and epigastric discomfort; gastrointestinal ulcers, asthma and pheochromocytoma are counter-indications to the use of this drug. 8 H1 receptor blockers and flunarizine, cinnarizine and calcium antagonists inhibit vessel constriction and act as vestibular sedative drugs, used in the treatment of both central and peripheral vertigo.…”

Betahistine in the treatment of tinnitus in patients with vestibular disorders

“…Drugs tried were: membrane stabilizers (lidocaine chlorhydrate), anti-seizure agents (carbamazepine, gabapentin), antidepressants (fluoxetine chlorhydrate; sertraline chlorhydrate), anxiolytics (clonazepam, alprazolam), Ginkgo biloba 761 extract, vasomodulators (flunarizine, cinnarizine and betahistine); the time of use for each drug and the criterion of choice depends on the clinical characteristics of each patient 14. There are studies showing that betahistine may provide symptom relief for tinnitus [15][16][17][18] . Betahistine is an H3 antagonist bloodreceptor and an H1 agonist receptor which improves inner ear microcirculation 19 , promoting and facilitating central vestibular compensation [20][21][22] . It is currently recommended to treat symptoms from many vestibular disorders [23][24] , including tinnitus.…”