If i stop takeing betahistine even for a day the vertigo comes back also the prescribe dose no longer work i currently take 1 8mg tablet 3 times?

Betahistine, vertigo: It all depends of the 1/2 life in your body, you can safely increase the dose, providing the symptoms are under control. Check with your DR. Biologic half- life of betahistine as determined by pharmacokinetic analysis is characterized by a high degree of variability (2-11 hours) with a mean of 5 hours. As a biologic effect in the brain is dependent upon the sustained availability of the active betahistine over a period of at least 6-12 hours it is crucial that an optimal formulation of betahistine exhibit a pharmacokinetic half-life (ti/2) greater than 5 hours and preferably 8-12 hours. Once or twice daily dosing could thereby achieve a sustained effect of betahistine to block brain histamine H3 Dose- and duration-dependent effects of betahistine dihydrochloride treatment on histamine turnover using a betahistine dihydrochloride formulation at oral doses roughly equivalent to those currently given to humans for Meniere's Disease (ie 24-48 mg/day), as well as 2 fold, 5 fold and 10 fold higher doses, found that to achieve a rapid biological effect on histamine H3 autoreceptors, 5 fold and 10 fold higher equivalent doses were required

Vertigo: Usually in the US, we do an extensive study for vertigo before Rx meds. Look into Vestibular rehabilitation & Canalith repositioning maneuvers if not tried. Otherwise, discuss med dosing with your MD.