Non sedating antihistamine comparison
Nevertheless, these studies may have been flawed and a review suggested that it is presently still unclear if betahistine has any effect in Meniere's disease (James and Burton, 2001).Unfortunately, most of the studies of betahistine have major design failings -- such as omitting a control group, or comparing betahistine to a homeopathic preparation.Essentially, the conclusion was that there is no evidence that Betahistine is harmful, but also little evidence that it has any therapeutic effect.It thus is similar in official status to an inert substance -- think sawdust perhaps.The withdrawal was upheld by a US court of appeals in 1968.Subsequently, four double-blind studies have been done reporting reduction of vertigo attacks with betahistine (Frew and Menon, 1976: Wilmot and Menon; 1976; Meyer, 1985; Mira et al, 2003).To our knowledge, this potential use has never been exploited.H3 antagonists appear to inhibit horizontal vestibular gain without affecting alertness.
Although betahistine does not closely resemble histamine (see above), in the body it is a histamine agonist. The rationale for its use is somewhat difficult to understand as H1 blocking antihistamines (such as meclizine) are also used quite commonly to treat vertigo.
Explanations commonly given are that the drug is a vasodilator, or that it acts on subreceptors of histamine.
H1 and H2 are post-synaptic receptors and H3 is a pre-synaptic receptor.
A recent exception is the study of Motamed et al (2017) where betahistine was found superior to promethazine.
Betahistine was again reviewed by the FDA in June of 1999 (click here for details).
Our clinical judgement is that betahistine does have positive effects on vertigo, but that it is very hard to determine how great these effects are due to the immense number of poor studies and biased reviews concerning betahistine's efficacy.