Updated: Jul 25, 2020
Levothyroxine is a synthetic formulation of T4 thyroid hormone.
-Once daily on an empty stomach in the morning 30 to 60 minutes before breakfast, or at bedtime on empty stomach
~1.7 mcg/kg/day, otherwise start with low dose in cardiac patients. Adjust dose every 6 to 8 weeks until both TSH, T3 and T4 are within range.
-Well-tolerated if it is the correct dose. If overtreatment, symptoms of hyperthyroidism appear, such as sweating, tremors and fast heartbeat.
-May exacerbate cardiac conditions such as atrial fibrillation, heart failure and MI.
-Chelation with antacids: iron, calcium, aluminum, magnesium - space by 4 hours
-Binders: cholestyramine, sodium polysterene sulfonate, psyllium fibre - separate administration