- Last edited on December 27, 2021
Levothyroxine (T4)
Primer
Levothyroxine (L-thyroxine, tradename: Synthroid), is a manufactured form of the thyroid hormone thyroxine (T4).
See main article: Triiodothyronine (T3)
Be careful dosing levothyroxine
Levothyroxine should only ever be prescribed in micrograms (mcg) to reduce the risk of prescription error. Common calculation errors when converting from mcg to mg (e.g. - 0.025mg to 25mcg (correct), may sometimes be mistakenly converted to 250mcg (a 10-fold dose increase error).Indications
- Hypothyroidism and myxedema.
Adverse Effects
- Tachycardia, heat intolerance, tremors, arrhythmias
- May be abused in those seeking weight loss