Does Synthroid Interact With Effexor, Pravastatin, Losartan, Mirtazapine, Calcium, Vitamin D3, B12, Vitron-C And CoQ-10 Supplements?

Posted on Sat, 10 Mar 2018

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

Sat, 10 Mar 2018 Answered on

Thu, 7 Mar 2019 Last reviewed on

Question : I started taking Synthroid at 0.025mg yesterday after a consultation with my Dr.; I cannot be sure but I feel like an interaction is going on...Can you tell me if this Thyroid Med. interacts with the following: Effexor, Pravatatin, Lorsartan, Mirtazapine, Calcium, Vit. D-3, Vitron-C, B-12, and CoQ-10? Unfortunately this is a weekend and I won't be able to contact my Primary Physican until Monday. Thank you.

Answered by Dr. Dr. Elona (28 minutes later)

Brief Answer:
There are some interactions.

Detailed Answer:

Hello,

I see that you take multiple medications.

Don't worry because If you use each drug exactly as prescribed by your doctor and you follow all directions on your prescription label, you will not have problems.

Among all these drugs, the calcium and ferrous fumarate in Vitron C can interact with each other.

Using calcium carbonate or ferrous fumarate together with Synthroid may decrease the effects of levothyroxine.

For this reason, these drugs should not be taken orally at the same time.

Products that contain iron or calcium may interfere with the absorption of levothyroxine and reduce its effectiveness.

My advice is to separate the dosing of these medications by at least 2 to 4 hours if possible.

Do not stop using any medications without first talking to your treating doctor.

Hope this is helpful.

Regards,
Dr. Elona Xhardo, Endocrinologist

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Above answer was peer-reviewed by : Dr. Arnab Banerjee