Medications for thyroid disorders: Nursing pharmacology

Thyroid disorders can be broadly divided into two categories which are on opposite ends of a spectrum: hypothyroidism, which describes a decrease in the thyroid hormones; and hyperthyroidism, which describes an increase in the thyroid hormones.

Now, thyroid hormones include triiodothyronine, or T3 for short, and thyroxine, or T4, and both contain iodine. The synthesis of these hormones is stimulated by another hormone, called thyroid stimulating hormone or TSH for short, which is released by the pituitary gland.Okay, so on one side of the spectrum, there’s hypothyroidism.

This is treated with thyroid hormone replacement therapy, which involves medications to replace the reduced thyroid hormones.

These medications include levothyroxine, which is a synthetic form of T4, and liothyronine, which is a synthetic form of T3.Both of these medications may be given orally or intravenously, and levothyroxine can be administered intramuscularly too.

Once administered, they bind to intracellular thyroid hormone receptors in tissue cells to mimic the actions of thyroid hormones, such as increasing the metabolic rate, body temperature and cardiac output.Now, the most common side effects of thyroid hormone replacement therapy include headaches, insomnia, nervousness, as well as weight loss, excessive sweating, and heat intolerance.

Some clients may also experience cardiovascular side effects, such as tachycardia, palpitations, and even cardiac arrest.Alright, now contraindications of thyroid hormone replacement therapy include thyrotoxicosis or a high level of thyroid hormones, as well as in clients with adrenal insufficiency, and those who had a recent myocardial infarction.

Also, as a boxed warning, these medications should not be used as obesity treatment.Now, on the other side of the spectrum, there’s hyperthyroidism.

This is treated with antithyroid agents like methimazole and propylthiouracil, which are administered orally. Once administered, these medications inhibit the synthesis of thyroid hormones by decreasing iodine use.Side effects of antithyroid agents include headaches, enlarged thyroid gland or goiter, and gastrointestinal disturbances like nausea, vomiting, and diarrhea.

In addition, clients may develop hepatitis and jaundice. In fact, propylthiouracil has a boxed warning for being highly hepatotoxic, potentially causing severe liver injury and acute liver failure.

Other important side effects include lymphadenopathy, vasculitis, and nephritis, as well as blood dyscrasias such as leukopenia and thrombocytopenia.

Some clients may also develop a skin rash, urticaria, and pruritus, as well as arthralgia, myalgia, and nocturnal muscle cramps.Finally, contraindications of antithyroid agents include pregnancy and breastfeeding.

However, as a boxed warning when absolutely necessary, propylthiouracil can be used during the first trimester of pregnancy.

Finally, antithyroid agents should be used with caution in infants, as well as in clients with bone marrow depression, bleeding disorders, or leukopenia.Alright, when caring for a client with a thyroid disorder, first ask your client about their symptoms, such as changes in energy level, appetite, physical appearance, weight, and degree of heat or cold tolerance.

Next, assess their weight and vital signs, noting any changes in blood pressure, temperature and heart rate. Then, review your client’s recent laboratory test results, including CBC, TSH, T3, and T4 levels, liver function tests, as well as their lipid profile.Now, before beginning thyroid replacement therapy with levothyroxine, be sure to explain to your client that the medication is a synthetic form of thyroid hormone, and let them know how it works to replace the thyroid hormone that their body no longer produces on its own.

Instruct them to take the medication with plenty of water on an empty stomach, at least 30 to 60 minutes before breakfast and 3 to 4 hours before taking other medications, such as acid reducing medications like proton pump inhibitors and antacids, or supplements like calcium and iron.

Encourage your client to maintain even hormone levels by establishing a daily routine of medication self-administration.

Additionally, caution your client against stopping their medication abruptly, and be sure they understand the need for lifelong hormone replacement therapy.

Then, let your client know that the most common side effect of levothyroxine is hyperthyroidism, which can manifest as a rapid pulse, palpitations, chest pain, tremor, trouble sleeping, weight loss, and heat intolerance.

Teach them how to take their own pulse, and stress the importance of contacting their healthcare provider right away if they develop symptoms of hyperthyroidism.

Now, if your client with hyperthyroidism is prescribed methimazole, be sure to explain that the medication reduces excess thyroid hormone production.

Instruct them to take their medication once each day, at the same time every day, and to never stop taking their medication abruptly.

Remind them that because the medication decreases thyroid hormone synthesis it can take several weeks to achieve the therapeutic effect.

Next, teach your client about side effects, and prompt them to immediately report if they develop symptoms of hypothyroidism, such as mental sluggishness, dry skin, weight gain, or cold intolerance; symptoms of blood dyscrasias, such as fever, sore throat, and fatigue; and symptoms of liver dysfunction, such as nausea, vomiting, anorexia, dark urine, or yellowing of the eyes or skin.

Lastly, advise your female clients to use a reliable form of birth control, and if they become pregnant, to let their healthcare provider know right away.

Finally, teach your client the importance of follow-up appointments and laboratory tests to monitor the effectiveness of therapy.

During treatment, monitor your client for resolution of symptoms, regularly check their laboratory values for normalization of thyroid hormone levels, and closely monitor for the development of side effects.

Alright, as a quick recap, medications used for treating thyroid disorders are used to restore the normal balance of thyroid hormone and prevent complications of either too little or too much thyroid hormone.

Levothyroxine and liothyronine replace missing hormones in hypothyroidism; and the most common side effects of these drugs include headaches, insomnia, nervousness, weight loss, and heat intolerance.

On the other hand, medications such as methimazole and propylthiouracil reduce thyroid hormone production in clients with hyperthyroidism.

Side effects of these medications include liver damage and bone marrow suppression. Nursing considerations are focused on monitoring for side effects and therapeutic outcomes, as well as providing client teaching on safe self-administration, how to recognize side effects, and the need for regular monitoring for the restoration of