Vertigo is a very odd symptom. When I get this I call it vestibular inflammation (caused by a virus) and for me at least it's treatable as long as I take valtrex.
Whenever I've had what I believe is vestibular inflammation (incredibly similair to vertigo if not exactly the same thing) I take 1g of valtrex and the symptom disappears in about 2 hours. Serum max is 1 hour so it makes sense. Have repeated this about 3 times. I no longer get this symptom anymore either so convinced it was one of the viruses valtrex works on.
But as you've said ivermectin I reckon these drugs could be antifungal or something as well and we don't know although ivermectin prob is antifungal I guess. As it's an anti parasitic right? Anyway I wonder if a wide variety of pathogens can cause the vertigo/vestibular inflammation. Just a thought.
And now I've found out that all ssris are highly anti fungal and most kill bacteria too. So could explain why those drugs might also work in some cases.