I have also, as Tedi, noticed that desferal lowers my blood pressure a little and that makes heart palpitations rise. I am talking about 80 pulses with ferriprox only and this rises to 90 with desferal and ferriprox together. Because of that, I have lowered the desferal dosage to 5 vials each time - while some years ago I took 8-10 vials per time and that presented with some problems: stomach ache, low pressure, palpitations. That happened only with desferal, when I was not on desferal those symptoms disappered.
So from what I personally have experienced, I concluded that when side effects appear one has to reestablish the dosage and of course, if one is "clean" one must not overdose oneself.
Lena.