Pharmacology- Endocrine -thyroid Treatment

Levothyroxine is the drug of choice for hypothyroidism because it is a synthetic form of the thyroid hormone thyroxine. It is used to replace the deficient levels of thyroid hormone in the body and helps to regulate metabolism and energy levels. Unlike radioactive iodine, which is used to treat hyperthyroidism, levothyroxine is used to treat the opposite condition of hypothyroidism. Thioamides and iodides are not typically used as the first-line treatment for hypothyroidism.

Hyperthyroidism is a condition characterized by an overactive thyroid gland, which leads to an excess production of thyroid hormones. This condition causes a hypermetabolic state in the body, leading to symptoms such as weight loss, increased heart rate, and anxiety. It is more commonly seen in women, with a prevalence rate of 2% throughout their lifetimes, compared to a lower prevalence rate of 0.2% in men. Therefore, the statement provided in the answer is correct.

The lab values consistent with the diagnosis of HYPOthyroidism would be low levels of T4 and T3, and high levels of TSH. This is because hypothyroidism is characterized by an underactive thyroid gland, which leads to a decrease in the production of thyroid hormones (T4 and T3). In response to the low levels of thyroid hormones, the pituitary gland releases more TSH to stimulate the thyroid gland to produce more hormones, resulting in high levels of TSH.

In hyperthyroidism, the thyroid gland produces excessive amounts of thyroid hormones. This leads to a negative feedback mechanism, where the elevated levels of T3 and T4 suppress the production of thyroid-stimulating hormone (TSH) by the pituitary gland. Therefore, in hyperthyroidism, the lab values would show suppressed TSH levels and elevated T3 and T4 levels.

Thioamides such as Methimazole and PTU inhibit thyroid peroxidase reactions, iodine organification, and peripheral conversion of T4 to T3. This prevents the synthesis of thyroid hormones.

• β-blockers
• Provide symptom relief- helps to control adrenergic manifestations
• Propranolol inhibits peripheral conversion of T4 to T3
• Propranolol- drug of choice
• Can use others… Atenolol, metoprolol
• Caution with CHF, asthma

Hyperthyroidism
• Almost solely caused by Graves’ disease
• Preferred Rx - treatment with 131I prior to pregnancy
• PTU during 1st trimester, (MMI assoc w/ fetal abn)
• Subtotal thyroidectomy in 2nd trimester is an option

Cretinism- Irreversible mental retardation and dwarfism caused by congenital hypothyroidism
Myxedema- Severe hypothyroidism
Goiter- Enlargement of the thyroid gland
Graves’ disease- Autoimmune disorder that results in hyperthyroidism

The recommendation for Thyroid function monitoring with any changes in preparations is every 4-6 weeks. This frequency allows for regular monitoring and adjustment of medication dosage if necessary, ensuring that the thyroid function remains within the desired range. Monitoring at this interval allows for timely identification and management of any changes in thyroid function, helping to maintain optimal thyroid health.

Propylthiouracil (PTU) is the drug of choice during thyroid storm because it inhibits the production of thyroid hormones by blocking the enzyme responsible for the conversion of T4 to T3. It also inhibits the peripheral conversion of T4 to T3. This helps to reduce the levels of thyroid hormones in the body and control the symptoms of thyroid storm. Methimazole is another antithyroid medication, but PTU is preferred in thyroid storm due to its additional peripheral action. Propanolol is a beta-blocker that can be used to manage the cardiovascular symptoms of thyroid storm. Iodine is not the drug of choice for thyroid storm but may be used in combination with PTU or methimazole to inhibit the release of thyroid hormones.

Thioamides, iodides, and propanolol are medications used in a patient with HYPERthyroidism. Thioamides, such as methimazole or propylthiouracil, work by inhibiting the production of thyroid hormones. Iodides, such as potassium iodide or sodium iodide, can temporarily reduce the release of thyroid hormones. Propanolol, a beta-blocker, helps manage symptoms such as rapid heart rate and tremors associated with hyperthyroidism. Levothyroxine, on the other hand, is used in HYPOthyroidism to supplement the low levels of thyroid hormones. Somostatin analogs are not typically used in the treatment of hyperthyroidism.

Methimazole is indeed the first-line treatment for hyperthyroidism in children, adolescents, and pregnant women. Methimazole is preferred because it is effective at controlling hyperthyroidism and has a lower risk of liver toxicity compared to propylthiouracil (PTU). However, in the first trimester of pregnancy, PTU is sometimes preferred due to a lower risk of birth defects associated with methimazole. After the first trimester, methimazole is typically resumed for the remainder of the pregnancy.

Therefore, the statement is True.

The correct answer is "I should avoid taking my Iron and calcium supplements at the same time as I take my Levothyroxine" and "I should take my medication on an empty stomach in the morning or at bedtime". These statements demonstrate understanding of the teaching about Levothyroxine medication. Taking iron and calcium supplements at the same time as Levothyroxine can interfere with its absorption, so it is important to avoid doing so. Additionally, taking Levothyroxine on an empty stomach in the morning or at bedtime helps ensure proper absorption of the medication.

Some causes of HYPERthyroidism include toxic diffuse goiter (Graves disease) and toxic adenoma. Graves disease is an autoimmune disorder that leads to the overproduction of thyroid hormones, causing hyperthyroidism. Toxic adenoma refers to the presence of a single, overactive nodule in the thyroid gland, which also results in excessive production of thyroid hormones.

Thyrotoxicosis, or hyperthyroidism, is a condition characterized by an overactive thyroid gland, leading to excessive production of thyroid hormones. The clinical features mentioned in the answer are commonly seen in individuals with hyperthyroidism. Nervousness and irritability are common symptoms due to increased stimulation of the nervous system. Tachycardia and arrhythmias occur as a result of increased heart rate and abnormal heart rhythm. Heat intolerance and increased perspiration are also common due to increased metabolic rate. These symptoms help in the diagnosis of hyperthyroidism.

The clinical signs of Hypothyroidism include bradycardia, palpably enlarged thyroid (goiter), skin pallor or yellowing (carotenemia), peripheral edema, puffy face and eyelids, and dry, pale skin. These are all symptoms that can be observed in patients with Hypothyroidism.

An elevated TSH can indicate that the patient's thyroid hormone levels are still low, suggesting that the dosage of Levothyroxine may need to be increased. However, before adjusting the dosage, it is important to assess for other potential causes of the elevated TSH, such as malabsorption or diarrhea, which could be affecting the absorption of the medication. Additionally, assessing for angina is important as it could be a symptom of underlying cardiovascular disease that may need to be addressed before adjusting the medication dosage.

Thioamides, such as Methimazole and PTU, are medications used to treat hyperthyroidism. The possible adverse drug effects (ADEs) of these medications include gastrointestinal (GI) symptoms such as nausea, rash, agranulocytosis (a condition characterized by a low level of white blood cells), hypothyroidism (underactive thyroid), and hepatitis (inflammation of the liver). These ADEs can occur as a result of taking thioamides.

Hypothyroidism with goiter can be caused by peripheral resistance to thyroid hormone, which means that the body is not able to effectively use the thyroid hormone. Certain drugs like Lithium and amiodarone can also cause hypothyroidism. Hashimoto thyroiditis, an autoimmune disorder where the immune system attacks the thyroid gland, is another cause. Additionally, Hepatitis C can lead to hypothyroidism.