The meds may not be the cause of the dizziness at all. It is certainly worth getting professional advice about that, and whether they may be draining you of any nutrients also.
However dizziness is a natural side effect of lowered blood pressure and can remain for the whole fast. It usually isn't a problem if we remain aware of it and avoid sudden movements especially getting up quickly from sitting or standing, and if you start feeling dizzy at any time more than usually sit down and take a break whatever you happen to be doing at the time.
I also think the dizziness could have something to do with the rapid weight loss and our centre of balance constantly changing.