In 1950s-70s Europe the doctors seemed to be prescribing it before folk got too fat (although it had been contraindicated for this use before I was born) but the side effects I read about seemed to be mostly related to mental health issues (psychosis) caused by continued use and comparatively few fatalities (given the huge amounts that were once prescribed).
Have seen a few more recent USA papers where they did mention some heart problems and all sorts else as side effects from 1990s era meds although its not clear what proportion of the total patients this is.
Of course for a person who is already obese to suddenly take stimulants when s/he is not used to them is very dangerous, I’ve known of non “druggie” types (such as middle aged professionals) to suffer harm and even fatal ODs of stuff like ephedrine based diet pills which were once rife in SE Asian countries, these pills finished off one our family friends in Malaysia (he was experiencing the weight gain many Asian males get during middle age and foolishly took what turned out to be a gross overdose).
At the other end of the scale have also heard of younger, athletic people (who regularly attend gyms etc) having problems with ephedrine (which certainly does speed up the heart rate) when they overdo it. (The amount available for purchase at any one time is restricted in UK and various other countries, although more for fear of it being illicitly converted into meth than risks from use on its own)
