It is not an overdose, it is a drug interaction
SSRI and SNRI's are Zoloft, Prozac, Paxil
, to name a few, SNRI - Effexor, Cymbalta, Pristiq.
Ultram taken at higher doses than prescribed with these can cause Serotonin syndrome which will cause you to pass out. If she says she has a shifting feeling in her head, with any of these drugs, it is definitely Serotonin Syndrome. When you move your eyes they seem to follow later, dry mouth, shifting brain, tired, disoriented somewhat.