I will be traveling from Miami to Rome, but I change planes in Madrid. is 1 1/2 hours enough time?
It is enough otherwise the airline would not sell you that ticket.
If you are flying Iberia or American I would not worry they will just put you on one of the 10 other direct flights to Rome from Madrid
I'm flying Air Europa, but like you said it should be ok if not they wouldn't sell it that way.
thanks,