Levothyroxine is synthetic T4 that speeds up metabolism. At the right dose it has no side effects, but too much causes hyperthyroid symptoms: fast heart rate, insomnia, and stomach upset. Remember: thyroid hormone equals metabolism.
Here are some key things to know about levothyroxine for your nursing school exams. Now, this is a synthetic form of T4, or the thyroid hormone. So if the dose is too high, it can cause hyperthyroid symptoms. Because this is that synthetic form of T4, if we give too much, if the dose is too high, it's going to cause symptoms of hyperthyroid. Now, anytime you think of thyroid, I want you to think metabolism. And with too much thyroid hormone, the metabolism in the body is going to speed up. With too little thyroid hormone, it's going to slow down. So anytime you think of thyroid hormone or the thyroid, think metabolism. If the dose is therapeutic, though, there should not be any side effects. But if the dose is too high, the patient could have symptoms of the metabolism speeding up. So increased heart rate, increased metabolism, insomnia and GI upset.
