I have used Florinef, Midodrine (vaso-constrictor) and salt for 19 years.

The sole purpose of Florinef, is as you said, to increase blood flow to the head. it does this by helping the body retain fluids and increase BP. The reason your BP increased when you took it is because that's exactly what the medication is supposed to do.

That goal you mentioned is exactly what those with NMH also need. Because that is what is needed when BP drops too.