Do these issues relate to the seizure risk on bupropion?
Quite likely. The reason for the equivocation is that so little is known about the pharmacology underlying the epileptogenic properties of bupropion. We do not know whether the risk is due principally to the parent drug or to one of its three major metabolites or to a combination of more than one of the four. Given this dearth of knowledge, how could this discussion be relevant to the risk of seizures on bupropion? First, an axiom of pharmacology is that some mechanism must underlie the epileptogenic effects of bupropion. Blockade of an ion channel is a good possibility as a potential mechnism mediating this effect since such a mechanism is common with other epileptogenic drugs. Second, the seizure risk with bupropion is clearly concentration dependent given the risk factors summarized in Table 3. If we knew the affinity of bupropion for the responsible site of action, we could plot it in Figure 1 and give a visual representation of the therapeutic index that exists with this drug (i.e
