From personal and anecdotal evidence, as there is really none to support this answer, you will likely be okay so long as you don't over-do the clen. Clen, and other sypmpathomemetics, stimulatnts, cause a realease of dopamine as well as nor-adrenaline. It is theorized that Bupriprion HCL(Wellburtrin/Zyban) is a Dopamine reuptake inhibitor and/or agonist. Too much dopamine, and with anything else in life, can cause more harm than good...i.e...mania for one extreme example. This "might" lead to an over stimulated heartbeat, but again, I don't think one can fine conclusive evidence of this. Just an example of a potential adverse reaction. Wellbutrin has been suggested as a weight-loss drug via its appeteite supression capabilities...which thorugh personal trial are profound. So, the combination of a selective Beta-2 agonist alongside a true and powerfull appeteite supressant could be an advantageus "synergistic" combination of drugs. Thoughm as I said earlier, caution must be used, as Wellburtin itself can cause adverse, hyper this-or-that, side effects as can Clenbuterol, or even ephedrine, caffiene, albuterol...ect...ect...with the beta agonists. Do use caution. Up your clen dose slowly and gradually, and do not mess around with your Bupriprion HCL dosage.