You want to be a research pharmacologist? Well I hear in the states, most
people do an undergraduate degree in biology/physiology; then a post
graduate degree pharmacology.

In europe and the rest of the world, most medical schools have pharmacology
departments where you can do an undergraduate degree in pharmacology. Then
you can go on and do a PhD.

Then you can go on and get a research position in a pharmaceutical firm, or
do some post-doctorate studies, and go down the achedemic road.

You could start over, and redo an undergraduate degree in pharmacology

Or, assuming you are very good at building models, programming, and
statistics, you can try your hands at being a graduate student in a research
group that does molecular pharmacology -- they love guys (or gals) like you
who can do hardcore math, since most pharmacology curricula don't teach any
math.  You'll still pick up the pharmacology from taking undergrad
pharmacology courses (as a graduate student, probably doing extra
assignments).

If I were you, I'd look into the second option.  To me that's far more
interesting.

... around here in the so-called Research Triangle area of North Carolina
pharmaceutical companies are always in dire need and are willing to pay top
dollar for statisticians with a medical/bio-chemical or pharmacology
background.