What exactly is an overdose of thyroxine for a hypothyroidism patient?

Excess drug resultin: Any dose that results in a hyperthyroid staate or symptomology is an overdose.

Symptomatic: Many times will treat based on symptoms once dz is confirmed (within a certain range of normal). If symptoms of hyperthyroid would cut down dose, ie anxiety, agitation, tremor, exophthalmos, palpitations, diarrhea, jittery, racing heart, overheating, significant wt loss, insatiable appetite etc....