Read the cautions on the Synthroid dosing instructions regarding factors that require starting out at a low dose and increasing slowly to develop tolerance (patient over 50, been hypo for
a long time, history af heart arrythmia, etc.). Initial dosage
is 1.7 mcg/kg/day. At 1.7 per kg, that's 386. My opinion...not a doctor, just a patient...don't ever do that to anyone...start lower and increase slowly.