Anti-vertigo drug

DETAILED DESCRIPTION OF THE INVENTION The anti-vertigo drug of this invention comprises as an active ingredient Afloqualone or a pharmaceutically acceptable acid addition salt thereof and exhibits excellent activity inhibiting vestibular nystagmus and hence is useful for the prophylaxis and treatment of an abnomality of the reflex system of a vestibulo-equibrium sense.
The activities of Afloqualone or a salt thereof has been confirmed by experiments.
For instance, Afloqualone was orally administered to cats (dose: 10 mg/kg) and its inhibitory effects on frequency, duration and maximum amplitude of per-rotatory nystagmus or post-rotatory nystagmus were measured 30 to 180 minutes after administration of the drug to be tested.
As a result, in per-rotatory nystagmus, the frequency, duration and amplitude of nystagmus were inhibited at a maximum of about 90%, 88% and 80%, respectively.
Besides, in post-rotatory nystagmus, the frequency, duration and amplitude of nystagmus were inhibited at a maximum of about 86%, 80% and 78%, respectively.
Moreover, a dose of 5 mg/kg, Afloqualone could inhibited the frequency and duration of per-rotatory nustagmus at a maximum of about 62% and 56%, respectively and further inhibited the amplitude of post-rotatory nystagmus at a maximum of about 52%.
In view of the action on sleep-awakefullness cycle, electroencephalogical study and also action against EEG arousal response induced by a stimulation of the brain stem reticular formation, it is unlikely that the inhibition of nystagmus by Afloqualone is would be based on the lowering action of consciousness at the above-mentioned dose.
Besides, as is clear from the fact that Afloqualone could inhibit vestibular nystagmus at a dose of about 1/4 (5 mg/kg, p.
o.
in mice) of ED.
sub.
50 (about 20 mg/kg, p.
o.
in mice) for muscular relaxation action thereof, Afloqualone shows high specificity on an equilibrium function in addition to the action in a muscle-controlling system, and hence, it can be used for prophylaxis and treatment of various symptoms such as desesthesia of motion and position, nystagmus, dysequilibrium, head deviation, nausea, vomiting, sweating, salivation and tachycardia