These 8 Medications May Cause Hypothyroidism

Some meds such as lithium and amiodarone may lead to drug-induced hypothyroidism or low levels of thyroid hormones, according to available studies. 

If you’re prescribed some of these meds, your healthcare provider may require blood work monitoring to be sure if the thyroid is affected or not. 

Regular monitoring and levothyroxine may treat hypothyroidism that has been induced by medications. Hypothyroidism occurs when meds you’re taking for other conditions are reducing the activity of the thyroid gland. 

If you’re worried that some of your meds could be reducing your thyroid gland functioning, keep reading to learn more. We’ll explore the most common meds associated with thyroid gland reduction in activity. 

Why Do Some Meds Lead to Hypothyroidism?

Our thyroid gland needs iodine in order to produce two chemicals, i.e., T3 and T4 hormones. These hormones are essential for the body because they participate in pivotal bodily processes like the maintenance of optimal temperature, metabolism, and heart rate. 

When the pituitary gland which is near the thyroid gland releases the thyroid-stimulating hormone, the thyroid gland is informed to produce more T3 and T4 into the body. 

In most cases, the meds that lead to hypothyroidism influence the thyroid-stimulating hormones, T3, and T4. Some of them are also associated with thyroiditis or inflammation of the gland. Excessive inflammation results in changes in the level of the above-mentioned hormones.

Below, check the eight most common meds that have been linked with hypothyroidism. Consult your physician if you’re worried about some of these meds leading to hypothyroidism. 

8 Meds That May Be the Main Culprits for Your Hypothyroidism 

  1. Amiodarone

Also known as Cordarone or Pacerone, this medication is given to people who have an irregular heartbeat. 

It’s 40 percent iodine and it may lead to hypothyroidism by blocking the formation of T3 or blocking the body’s signal which informs the gland to produce T3 and T4. 

The risk of this medication affecting your thyroid is higher if the thyroid isn’t working optimally. 

  1. Meds for hyperthyroidism

Meds that are given to address hyperthyroidism like methimazole, radioiodine, potassium iodine, and PTU have the side effect of causing the thyroid hormones to drop down. 

They shrink the thyroid gland in order to decrease the excessive production of thyroid hormones, but this can sometimes cause a major decline and end up causing hypothyroidism. 

  1. Lithium

Given to patients with bipolar disorder, lithium has been associated with hypothyroidism. It’s more common in women older than 45 as well as in people with a family history of hypothyroidism. 

The older a person is, the higher the likelihood of them suffering from hypothyroidism due to lithium. 

  1. Thalidomide 

Despite being quite uncommon, there are reports of individuals who have hypothyroidism due to taking thalidomide. 

However, experts aren’t sure why this medication is associated with hypothyroidism. This medication is used for the treatment of various conditions, including leprosy and multiple myeloma. 

  1. Checkpoint inhibitors

These meds are used for the treatment of tumors. Some examples are Opdivo and Yervoy. However, they also lead to hormonal changes, including the ones secreted by the thyroid. 

In several studies, between 4 percent to 14 percent of people who received this medication also had hypothyroidism. And, the risk was the highest with combination therapy.

  1. Interleukin-2 

Prescribed for the treatment of leukemia and other types of cancer, this medication has also been associated with hypothyroidism. 

In fact, a small percentage of individuals who were taking this medication developed thyroiditis, a condition that may contribute to a higher risk of hypothyroidism. 

  1. Interferon alfa

Given for the treatment of melanoma, leukemia, non-Hodgkin’s, Kaposi’s, hepatitis, and HPV, this medication may also lead to thyroid function changes if it’s taken for a longer period of time. 

This medication also causes the body to produce antibodies that prevent the thyroid gland from functioning optimally. In fact, up to 15 percent of individuals with these antibodies will suffer from a thyroid disease such as hypothyroidism. 

  1. Tyrosine kinase inhibitors

This type of medication is used for the treatment of leukemia and other types of cancer. Unfortunately, up to 40 percent of people who take this type of medication will develop hypothyroidism. 

Studies have also concluded that this may occur within a couple of weeks or after several months after starting the therapy.