If a vestibular disorder is present and thought to be secondary to active Meniere disease or vestibular neuronitis or labyrinthitis, the most effective vestibular nerve suppressants are oral antihistamine / anticholinergic drugs (eg, meclizine 25 to 50 mg 3 times a day) or diazepam (2 to 5 mg orally every 6 to 8 hours, with higher doses given under supervision for severe vertigo).