Drug-Induced Nutrient Depletions: What Pharmacists Need to Know

Patients on high dosages of levothyroxine (greater than 200 mcg per day) with persistently elevated TSH levels may be nonadherent or have absorption issues attributed to meal timing or other medications1,5,20 (Table 5 and Table 820). Some patients may experience persistent symptoms despite adequate dosing of levothyroxine to a normal TSH level; therefore, other etiologies should be considered and evaluated accordingly (Table 41,2). Hypothyroidism occurs when there is inadequate thyroid hormone production by the thyroid gland or insufficient stimulation by the hypothalamus or pituitary gland. Causes may include primary gland failure or can be iatrogenic, transient, or central (Table 1).1–4 Central causes, such as low levels of thyroid-stimulating hormone (TSH) and free thyroxine (FT4), are rare. Serum thyroid-stimulating hormone measurement is the most sensitive test for diagnosing hypothyroidism. In primary hypothyroidism, there is decreased feedback inhibition of the intact pituitary, and serum TSH is always elevated, whereas serum free T4 is low.

It’s important to always take your medication exactly as your doctor prescribed. Sometimes, deficient TSH secretion due to deficient TRH secretion is termed tertiary hypothyroidism. The “optimal dose” was determined for each patient as that dosage of thyroxine being taken when the thyrotropin-releasing hormone (TRH) response was normal (ie, an increase in TSH of between 4.7 and 25 mIU/L). Enter medications to view a detailed interaction report using our Drug Interaction Checker. Armour Thyroid is used for hashimoto’s disease, hypothyroidism, after thyroid removal, thyroid …

Jennifer is a 32-year-old woman in her first trimester of pregnancy with

An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Some patients with a normal TSH level and symptom resolution may become symptomatic again with or without a change in TSH. When symptoms reappear without a change in TSH level, the physician should consider nonthyroid etiologies. When there is an accompanying change in the TSH level, especially in a patient who has stayed on a stable dosage for some time, other reasons should be explored before adjusting the levothyroxine dosage. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Reduce Side Effects

In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction. Larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects. This central role is reflected by the signs and symptoms of thyroid dysregulation. Thyroid hormone also regulates thyroid metabolism by providing negative feedback to the hypothalamus and pituitary gland.

Most patients with goiters not caused by Hashimoto thyroiditis are euthyroid or have hyperthyroidism. In response, TSH is released, which causes the thyroid to enlarge and trap iodine avidly; thus, goiter results. If iodine deficiency is severe, the patient becomes hypothyroid, a rare occurrence in the United States since the advent of iodized salt. Note that this list is not all-inclusive and includes only common medications that may interact with Synthroid.

Women with hypothyroidism who become pregnant should increase their weekly dosage by 30% up to nine doses per week (i.e., take one extra dose twice per week), followed by monthly evaluation and management. Patients with persistent symptoms after adequate levothyroxine dosing should be reassessed for other causes or the need for referral. Early recognition of myxedema coma and appropriate treatment is essential.

Hypothyroidism is generally a lifelong condition requiring lifelong treatment. By continuing to take Synthroid as your doctor prescribed and getting your levels checked regularly, you can help keep your thyroid hormone levels where they should be. Medicines that interact with Synthroid may either decrease its effect, affect how long it works, increase side effects, or have less of an effect when taken with Synthroid.

• You should refer to the prescribing information for Synthroid for a complete list of interactions.
• Hypothyroidism is generally a lifelong condition requiring lifelong treatment.
• In severely iodine-deficient regions worldwide, congenital hypothyroidism (previously termed endemic cretinism) is a major cause of intellectual disability.
• Certain other medicines may also increase or decrease the effects of Synthroid.

Drug-Induced Nutrient Depletions: What Pharmacists Need to Know

This causes the body’s system to slow down and can lead to symptoms like fatigue, feeling cold, weight gain due to fluid synthroid women retention, dry skin, and hair loss. In patients with secondary hypothyroidism, levothyroxine should not be given until there is evidence of adequatecortisol secretion (or cortisol therapy is given), because levothyroxine could precipitate adrenal crisis. Levothyroxine therapy is also indicated in pregnant women and in women who plan to become pregnant to avoid deleterious effects of hypothyroidism on the pregnancy and fetal development. Patients should have annual measurement of serum TSH and free T4 to assess progress of the condition if untreated or to adjust the levothyroxine dosage. Hypothyroidism may occur in patients taking lithium, perhaps becauselithiuminhibits hormone release by the thyroid.

Treatment of Hypothyroidism

Et al. observed a high prevalence of bone loss in patients treated with thyroxin.37 Vestergaard and Mosekilde studied 11,776 patients with hyperthyroidism and 4473 patients with hypothyroidism in terms of bone fracture. In hyperthyroid patients, the fracture risk was significantly increased only at the time of diagnosis, but after the diagnosis and treatment, fracture risk was reduced. Surgical treatment of hyperthyroidism reduces the risk of bone fractures, but fracture risk in hypothyroid patients both before and after diagnosis was significantly increased. The present study also showed that at the time of diagnosis of hypothyroidism, BMD was not significantly different from normal subjects.

Secondary hypothyroidism is characterized by skin and hair that are dry but not very coarse, skin depigmentation, only minimal macroglossia, atrophic breasts, and low blood pressure. Also, the heart is small, and serous pericardial effusions do not occur. Hypoglycemia is common because of concomitant adrenal insufficiency or growth hormone deficiency. Symptoms and signs of primary hypothyroidism are often subtle and insidious. The most common presenting symptoms are fluid retention and puffiness, especially periorbitally, tiredness, cold intolerance, and mental fogginess. For patients with TSH levels between 4.5 and 10 mUI/L, (4.5 and 10 microIU/L) a trial of levothyroxine is reasonable if symptoms of early hypothyroidism (eg, fatigue, depression) are present.