well... we don't naturally have 'ssri levels' it is an ssri (meridia aka.. sibutramine hcl) ssri is selective serotonin re-uptake inhibitor... inhibits the re-uptake of serotonin and it's further breakdown into other metabolites, so serotonin will be higher.... it also has some effect on the andrenergic system... with re-uptake inhibition... I don't believe that it acts as an neurotransmitter by it's self...
it's not an amphetamine, I have no clue what metabolites it could break down to, but I don't expect that your body is going to synthesize it into one...
anyway, I admit I don't know a lot about it, but I just decided to add what I thought might be useful...