CHANGE FROM ARMOUR TO SYNTHROID

[Liz1900]

Hello Dr. Lupo,

    I wrote to you last month about problems I was having with Armour thyroid after taking it for 40 years - heart palpitations and feeling generally lousy most of the time.  You advised me that the T3 in Armour was heart stimulating and sometimes as we age, the heart can't handle it.  You also said if it continued, I may have to be switched to straight T4, Synthroid.  That is exactly what happened this week.  I kept having the heart palpitations and feeling worse than ever - seemed like the Armour was becoming toxic and poisoning me.  Anyway, I stopped the Armour yesterday and started the Synthroid today.  I noticed that my heart doesn't seem to be racing as much.

How long does it take for the Armour to get out of my system?   I still feel very tired and weak, but it has only been a day - how long do you think it will take for my body, at 65, to adjust to the Synthroid and I would feel some better?  Doctor started me at low dose - 50 mcg. with blood work in 4 weeks.  What can I expect in the way I feel?

Thanks,.
Liz

[Mark Lupo, M.D.]

It takes 2-3 weeks to begin to feel the synthroid and the initial dose may be a little low, so close monitoring and titration (as planned in 4 weeks) are important.  The T3 gets out of the system in 1-2 days, the T4 component of the armour takes about 2-3 weeks to clear significantly.

[authrjenn]

Yesterday my new doctor started me on Armour. I have been taking Generic synthroid after having severe adjustment issues. Since I am hyper-sensitive and 57, she suggested I begin taking one 30 mgs per day. My body was used to receiving 112 mgs of Levothyroxine until today. Is 30 mgs of Armour enough or should I take 60mgs.?