Does Levothyroxine Cause Heart Palpitations?

Posted on Sat, 5 Dec 2015

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Sat, 5 Dec 2015 Answered on

Mon, 28 Dec 2015 Last reviewed on

Question : Hi, I recently began having some issues with my levothyroxine I have been splitting my 50mg in half and just recently began having some issues with what felt like pounding heartbeat. Is this something I should discontinue using?

Answered by Dr. Anshul Varshney (39 minutes later)

Brief Answer:
Get a repeat thyroid profile.

Detailed Answer:
Welcome to Healthcaremagic.
Hi, I am Dr Anshul Varshney , I have read your query in detail , I understand your concern.
Since you have been prescribed 50 mcg of levothyroxine, so that must be the optimal dosage for you. Now since you have been taking half of the dosage so you need to get your thyroid functions re-evaluated to find out the cause.
I would say, that taking half of the prescribed dosage is not going to cause pounding heart beat (palpitations) because taking lesser dose may not be able to control your hypothyroidism but palpitations are not found in hypothyroidism.
One possibility is that the half of your dosage is also getting high for you and you are converting from hypothyroid to hyperthyroid.
Other possibilities for such palpitations includes cardiac issues, anxiety.
You need to be sure of your thyroid status and getting a repeat thyroid profile is the best way out.
This is my personal opinion based on details available here. If you still have any other query, you may please ask me.
Stay Healthy.
Dr Anshul Varshney , MD

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Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar