Levothyroxine Therapy in Patients with Thyroid Disease

  title={Levothyroxine Therapy in Patients with Thyroid Disease},
  author={Susan J. Mandel and Gregory A. Brent and P. R. Larsen},
  journal={Annals of Internal Medicine},
Levothyroxine is one of the 13 most commonly prescribed medications in the United States, with more than 15 million prescriptions filled annually [1]. It is given as either physiologic replacement therapy in patients with hypothyroidism or as interventional therapy to suppress thyroid-stimulating hormone (TSH) secretion in patients with nodular thyroid disease or thyroid cancer. Overt hypothyroidism occurs in 1.5% to 2% of women and in 0.2% of men [2], and its incidence increases with age… 

Variations in adequate levothyroxine replacement therapy in patients with different causes of hypothyroidism.

  • M. B. GordonM. Gordon
  • Medicine, Biology
    Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists
  • 1999
The levothyroxine replacement dose varies with the cause of the hypothyroidism, and a normal thyrotropin level and clinical euthyroidism in patients with primary hyp Timothyroidism and a serum free thyroxine index in the upper half of the normal range in conjunction with clinical euthYroidism is defined.

Management of thyroxine therapy during pregnancy.

  • M. Kaplan
  • Medicine, Biology
    Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists
  • 1996
The increment in T4 dose needed to normalize an increased TSH level in women taking T4 can be estimated from the serum TSH concentration during pregnancy, and the optimal schedule is uncertain.

Evaluation of the adequacy of levothyroxine replacement therapy in patients with central hypothyroidism.

The results indicate that the diagnosis of CH is reached at best by measuring TSH and FT4 concentrations, and both FT4 and FT3 serum levels together with some biochemical indexes of thyroid hormone action are all necessary to a more accurate disclosure of over- or undertreated patients.

Prevalence of Iatrogenic Hyperthyroidism in a Community Hospital

The frequent use of levothyroxine suggests that TSH suppression could represent a serious public health concern, particularly for postmenopausal women and patients with heart disease.

Management of Hypothyroidism in Adults

A small subgroup of patients well controlled on levothyroxine monotherapy with TSH in euthyroid range still complain of persistent symptoms suggesting that a combination of thyroxine and triiodothyronine may improve the quality of life in such patients.

Thyroxine replacement: a clinical endocrinologist’s viewpoint

Despite the availability of thyroid hormone replacement for more than a century, there are still substantial challenges in practice and opportunities to improve treatment outcomes.

Delayed intestinal absorption of levothyroxine.

Full suppression or normalization of TSH is obtained by postponing breakfast for at least 60 min after T4 ingestion by patients in whom TSH-suppressive or replacement L-T4 therapy failed to suppress or normalize serum TSH.

Misuse of levothyroxine and the rate of achieving target thyroid-stimulating hormone in levothyroxine treatment

Investigating the misuse of levothyroxine treatment in patients with hypothyroidism found that taking the medication on a full stomach or in the evening, occasional use of medication, storing the medicine in the refrigerator, and the use of additional medications were the major factors for insufficient TSH levels.

Medication use in the hypothyroid patient.

Thyroid Hormone Replacement During Pregnancy

Although never demonstrated with certainty that there is an increase in thyroid production from early pregnancy, laboratory parameters suggest very strongly that such an increase occurs in response to physiologic changes in thyroid economy.



Thyroid failure in the elderly. Microsomal antibodies as discriminant for therapy.

Results suggest that among older patients with isolated elevations of the TSH level, only those with markedly elevated TSH levels or high-titer antimicrosomal antibodies should be prophylactically treated with levothyroxine sodium replacement.

Monitoring thyroxine treatment during pregnancy.

  • M. Kaplan
  • Medicine, Biology
    Thyroid : official journal of the American Thyroid Association
  • 1992
Data were analyzed from 77 pregnancies in 65 hypothyroid women treated with levothyroxine (T4) to determine (a) how often, how severely, and when serum thyrotropin (TSH) and free T4 concentrations

Changes in serum thyroid hormone, thyrotropin and thyroglobulin concentrations during thyroxine therapy in patients with solitary thyroid nodules.

It is demonstrated that serum Tg levels decrease when T4 therapy is effective, which may prove a useful indicator of the efficacy of T4 Therapy in patients with solitary thyroid nodules.

Suppressive therapy with levothyroxine for solitary thyroid nodules. A double-blind controlled clinical study.

It is concluded that the efficacy of levothyroxine therapy in reducing the size of colloid thyroid nodules is not apparent within six months, despite effective suppression of thyrotropin.

Transient elevation of serum thyroid hormone concentration after initiation of replacement therapy in myxedema.

Serum T4 and T3 concentrations during the first 6 months of therapy do not reflect the optimal dose of T4 replacement on a long-term basis, due to a decrease in the metabolic clearance rate of the absorbed hormone associated with hypometabolism.

L-Thyroxine therapy in subclinical hypothyroidism. A double-blind, placebo-controlled trial.

L-Thyroxine therapy may be useful for patients with subclinical hypothyroidism with abnormal myocardial contractility or symptoms consistent with mild hypothy thyroid hormone action, or both.

The aging thyroid. Thyroid deficiency in the Framingham Study.

In an unselected population of elderly (over age 60 years) men and women (the original cohort of the Framingham Study), the prevalence of thyroid deficiency, evidenced by a clearly elevated serum

Aging and the thyroid. Decreased requirement for thyroid hormone in older hypothyroid patients.

The aging thyroid. The use of thyroid hormone in older persons.

In chronic users of thyroid hormone, it is important to review currently appropriate indications and to measure serum thyrotropin levels to assess the adequacy of treatment of primary hypothyroidism.