See considerations below concerning Serc regarding the rationale for use. Serc, however is not entirely equivalent to Histamine. This drug is advocated as a histamine agonist. Curiously, Serc was approved by the FDA for roughly 5 years, but later approval was withdrawn because of irregularity in the studies which supported the original approval. Serc is not sold through ordinary US pharamacies but it can be obtained through US compounding pharmacies.
Explanations are that the drug is a vasodilator, or that it acts on subreceptors of histamine.
Most antivertigo drugs such as meclizine are H1 blockers. Many medications for stomach problems are H2 blockers. Serc is an H3 antagonist, according to Timmerman. The precise role of H3 is presently uncertain, which allows for the possibility that it might be important in vertigo. Confusingly, some authors suggest that Serc is an H3 agonist.