I've got both problems, and, am taking both Metformin (850 mg x2) and Advair
(500/50 x2) and have lately been having problems with a "tightness" in my
chest and some chest "pains".  I've had thorough tests for heart problems,
and, have none, but couldn't get rid of these problems (although my chest
would feel tight, I could blow the end of a spirometer off, so, wasn't
really having any blockage).

I went off both meds last Thursday, and...the symptoms went away.  I started
getting low-grade asthma symptoms (easily reversible with Albuterol) Sunday,
so, went back on the Advair, and, am feeling clear with no chest symptoms.
Will restart the Metformin Tuesday to see if they come back.

I'm concerned that it's either the Salmeterol or the Metformin or a combo
effect causing this issue, and was wondering if any out there have had
similar issues, and were able to get around them?

Thanks.