Dr. stated plaquenil (hydroxychloroquine) could also be the reason for my vertigo - could vertigo really start 8 months after taking it? i don't want to stop this drug.

Hydroxychloroquine: This drug can produce numerous side-effects with neurological overtones, including vertigo, but it is unusual (although not impossible) to have these develop after 8 mos of treatment. Suggest you work this out with the rheumatologist to see whether this may be related more to your underlying illness than to the plaquenil (hydroxychloroquine). Sound like you are already having this assessed. Good luck.