Hello, Friend. Please talk this over thoroughly with your Doctor before you stop your medication, even if you taper off very slowly. When we read about clinical trials and side-effects virtually all medications will list "horror stories" in short form. And it is not always certain that some of those side-effects were actually due to the medication in question. Of course, you have identified the increased heart rate (tachycardia) yourself. I also suffer from Depression and take a related medication, Cymbalta. Pristiq and Cymbalta are in the same class of anti-depressants. (Effexor, Celexa, and Lexapro are as well.) Another consideration is whether you will be starting a new medication to replace the Pristiq. Often, though it is not always possible, the Physician will order a start of the replacement medication and gradually titrate the new med up as the old med is gradually lowered. I, too, tend to have a high heart rate due to one or more of my medications for depression and some related issues. However, the benefits of my medications (also on Depakote and Xanax) are far too great to discontinue them due to higher heart rate. (Actually, I could probably lower that rate by quiting all caffeine and exercising more.) I appreciate your situation re: the increased pulse occurs as the Pristiq "kicks in." Your physician may have advice or even a possible treatment to reduce this tachycardia. I hope this is useful. My best to you.