I dont remember the exact names but it basically goes like this.
Tramadol gets converted in the liver when taken orally to Desmethyl Tramadol which is the metabolite that gives the nice recreational opiate effects, thats why some people find tramadol shit and non recreational because they have lower level of enzymes that process tramadol to desmethyl tramadol, when snorting it you actually end up with way less desmethyl tramadol so your experience will be LESS recreational and yes I believe the chances of seizures and other unwanted side effects increase, basically the best way to take tramadol would be some nice instant release pills orally, on that note I dont know about IV, in my country where its over the counter some people like buying the IV solution and slamming it, I dont know how effective it is that way to be metabolized to desmethyl tramadol but I wouldnt inyect tramadol if someone paid me 1000 dollars, of course never IV pills.