[Antivertiginous action of vitamin B 6 on experimental minocycline-induced vertigo in man]

By means of a former investigation it has been proved equilibriometrically that the application of 7 X 100 mg minocycline may induce a central equilibrium dysregulation of the brainstem type. It was the purpose of this study to further assure that the minocycline induced brainstem vertigo is due to a destabilization of a supervisory gamma-aminobutyric acid (GABA)ergic loop from the archeocerebellum upon the pontomedullary vestibular regulating pathways. As it is pharmacologically known that pyridoxine is essential for the synthesis of GABA, an inhibitory CNS neurotransmitter, 2 separate double blind trials on 20 healthy young persons each were carried out after the intake of 7 X 100 mg minocycline during 3 days with and without 7 X 40 mg pyridoxine simultaneously. These trials were checked against an additional placebo or initial non drug investigation. In all the 40 test persons it could be proved that the amount of vertigo and nausea symptoms was increased significantly due to the application of minocycline only. However, when combining minocycline with vitamin B 6, the vertigo and nausea symptoms as well as the nystagmus signs from the monaural and the binaural vestibular ocular tests as well as the vestibular spinal signs from the craniocorpography recordings of the stepping and the standing procedures were remarkably reduced. There were no statistical differences between the initial or placebo trials versus the trials with a combination of minocycline with vitamin B 6. The same holds for the vestibular vegetative reactions, measured by the simultaneous electrocardiography during the vestibular tests. All the equilibriometric tests applied showed a significant destabilization under the influence of a pure minocycline loading.(ABSTRACT TRUNCATED AT 250 WORDS)