Can clonidine lower heart rate? Having POTS, my HR is usually 115 on a good day. The past 2 weeks it's been as low as 40 bpm.

Yes. Loweing heart rate is a side-effect of this centrally acting anti-hypertensive. For a paitent with POTS, I donot believe Clonidine is the best drug for treatment of hypertension becuase of its effect on the autonomic system. See a cardiologist or electrophysiologist, and get another antijypertensive. Note, when weaning off clonidine, you can also get a rebound hypertension. So you need to follow.
Clonidine. Clonidine lowers blood pressure and can slow the heart rate,but 40/min is very slow. An EKG should be done to identify the type of heart rhythm and get an accurate heart rate. Clonidine should be tapered and not stopped abruptly if possible as a rebound rapid heart rate can occur. Discuss the problem with your physician.