Vertin is the brand name of a medicine called betahistine. It is an analogue of histamine.
Stugeron is the brand name of medicine called cinnarizine. It belongs to a group of medicines called anti-histamines (popularly used for allergy).
Theoretically, analogues of histamines should counteract the effect of anti-histamines and hence should not be used concurrently. However in the field of medicine, unlike arithmetic, sometimes 2 + 2 do not add up to 4. Normally, in such cases, drug trials are conducted to see the actual effect in practice. No conclusive trials have been reported on the concurrent use of betahistine with cinnarizine.