Thyroid T4 (Synthroid)
Neurohormone
- Hypothyroidism
- Use T4 for hypothyroid, T3 for depression
- Maintain TSH near 2.5 in patients on lithium to prevent depression.
Features
Dosing
50 mcg 1 qd (best to take 1 hour away from food and other meds). Then dose based on labs (when using for hypothyroidism).
Management
T4 is best to use for hypothyroidism while T3 (which is more active in the CNS) is better for treating depression with supraphysiologic thyroid. T3 can also be safely added to a patient on T4. T4 actually converts to T3 in the liver, so when you give T4 about 30% of it turns into T3.
EMR Text
Hypothyroidism
Levothyroxine started for the treatment of hypothyroidism.