Pharm, part 34: Endocrine Medications - Thyroid and Anti-Thyroid

by Cathy Parkes September 06, 2021 Updated: September 15, 2021

Full Transcript

Hi. I'm Cathy, with Level Up RN. In this video, I'm going to continue my coverage of endocrine system medications. Specifically, I'll be covering thyroid and anti-thyroid medications. If you have our Level Up RN Pharmacology Second Edition Flashcards, definitely pull those out and follow along with me. At the end of the video, I'm going to provide a quick quiz for you guys to test your understanding of some of the key facts and concepts that I'll be covering in this video. So definitely stay tuned for that.

So let's start by talking about our thyroid medications which include levothyroxine as well as liothyronine. So these medications really act as a synthetic form of our naturally occurring thyroid hormones, and we would use them in the treatment of hypothyroidism.

So side effects are minimal unless the dose is too high. In that case, we may end up with signs and symptoms of hyperthyroidism.

So signs and symptoms can include anxiety, GI upset, sweating, weight loss, and heat intolerance if the patient has hyperthyroidism.

There's also a black box warning with this medication class to warn people that thyroid hormones are not to be used for the treatment of obesity or to help the patient lose weight. In terms of the dosing, we're going to want to closely monitor the patient's TSH and T4 levels, and, periodically, we may need to increase or decrease their dose according to whatever those TSH and T4 levels are.

We also want to educate the patient that lifelong treatment is required with these thyroid medications, so it's not like they're going to take levothyroxine for a little while and suddenly their thyroid gland is going to produce sufficient T3 and T4. That's not going to be the case, so they're going to need to take this for the rest of their lives. The dose may need to be adjusted at times, but it will be lifelong treatment.

In terms of administration, we want to counsel the patient that they should take this medication on an empty stomach with a full glass of water before breakfast. So at our hospital, we wake our patients up at 6:00 AM and give them their thyroid medications with a full glass of water well before the breakfast trays are delivered to the floor.

So in terms of how I remember that these medications are used to boost up the thyroid hormone levels, if you look at the drug names levothyroxine or liothyronine, they both have that thyro, so T-H-Y-R-O. And that helps you to remember that these medications are used to treat thyroid disorders.

All right. Now, we're going to talk about anti-thyroid medications, and there are two different medications I'm going to talk about. The first is propylthiouracil or PTU. So PTU is used in the treatment of Grave's Disease, which is a key cause of hyperthyroidism. It is also used in preparation for a thyroidectomy. So PTU works by blocking the synthesis of thyroid hormones, so it helps to bring those levels down.

In terms of side effects, side effects include agranulocytosis, which is a decrease in granulocytes, which is a type of white blood cell. So with this side effect, it does place the patient at increased risk for infection. Other side effects include GI upset, rash as well as hepatotoxicity, which is a black box warning for this medication class. Also, if the patient's dose of PTU is too high, it can cause signs and symptoms of hypothyroidism.

So this includes symptoms such as lethargy, weight gain, cold intolerance, bradycardia, and depression. So as the nurse, when a patient is on PTU, you want to monitor their CBC levels because of that side effect of agranulocytosis. And we're also going to want to monitor their liver function because of that side effect of hepatotoxicity.

So the way I remember this medication and what it's for when I look at P-T-U, I think of prevents thyroid for being up too high, and that's exactly what it does. It prevents those thyroid levels from being up too high. It brings them down.

Another anti-thyroid medication to know is something called Lugol's solution, which is a strong iodine solution. So this is a combination of iodine and potassium iodide, and it is used in the treatment of hyperthyroidism as well as thyrotoxicosis, which is a severe form of hyperthyroidism that's life-threatening. It could also be used in preparation for a thyroidectomy. So Lugol's solution is absorbed by the thyroid gland, and there it inhibits the production and release of thyroid hormones.

Side effects can include GI upset, hypothyroidism and iodism.

So signs and symptoms of iodism include a metallic taste, stomatitis, which is inflammation of the mucosa in the mouth as well as severe gastrointestinal upset. So this medication tastes really bad, apparently. I've never personally had it, but that's my understanding. So you can mix it with a lot of water or with juice to try to mask that taste.

Okay. Time for a quiz. Question number 1. Levothyroxine should be given once a day with food. True or false? The answer is false. It should be given without food and a full glass of water before breakfast. So remember, we wake up our patients at my hospital at 6:00 AM to give them this medication with a full glass of water.
Question number 2. What anti-thyroid medication carries the risk for iodism? The answer is a strong iodine solution or Lugol's solution.
Question number 3. If a patient's dose of PTU - so that's propylthiouracil - is too high, what side effect would we expect? The answer is hypothyroidism. So remember, PTU prevents the thyroid from being up too high, so it reduces those thyroid levels. So if we do that too much, then the patient will end up with hypothyroidism.

Okay. I hope these quiz questions have been helpful. Hopefully, the video helped as well. If you got any of these questions wrong, just go back and review the flashcards or replay the video. I know you've got this, so take care and good luck studying. I invite you to subscribe to our channel and share a link with your classmates and friends in nursing school. If you found value in this video, be sure to hit the Like button and leave us a comment and let us know what you found particularly helpful.

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