Fasting for blood sugar test.

I've never heard of a lab or doctor saying it's ok to drink coffee before a fasting blood test.  In fact, some people say that caffeine actually will raise their blood sugar.  And I also question the decision to put you on a medication from that fasting test.  If I were you, I'd have a talk with the doctor and request another test.  (I'm not a doctor, mind you, but this seems very irregular in my opinion.)  A random blood test might indeed show an elevated blood sugar but there may be other factors that caused it, not diabetes.  Normally, a doctor will order a fasting on more than one occasion and along with the fasting report, he would have an A1c reading which will tell you what your average blood sugar was during the past 3 months.  I would not rule out that you do have some pre-diabetes tendency but it might be able to be controlled by diet and exercise at first, so if it were me, I'd go back and talk to the doctor.