Lithium thyroid gland

Drug Interactions with Lithium Lithium and the Thyroid Gland Lithium and Bone Microbiological Effects of Lithium Conclusion References... 

Lithium is concentrated in the thyroid gland and can impair thyroid hormone synthesis. Although goiter is uncommon, as many as 30% of patients develop at least transiently elevated thyroid-stimulating hormone values. Lithium-induced hypothyroidism is not usually an indication to discontinue the drug. Patients can be supplemented with levothyroxine if continuation of lithium is desired.30... 

Hypothyroidism Hypothyroidism may occur with long-term lithium administration. Patients may develop enlargement of thyroid gland and increased thyroid-stimulating hormone levels. 

Biosynthetic defects in thyroid hormonogenesis may also result in an inability of the thyroid gland to produce sufficient hormone and may be due to inherited enzymatic deficiencies or the ingestion of natural or therapeutically administered antithyroid agents. An example in the latter category is lithium, widely used to treat psychiatric disorders and associated with the development of hypothyroidism and goiter. It is concentrated by the thyroid, where it inhibits thyroidal I uptake, incorpora-... 

Lithium affects thyroid function (52-56), and in most patients, after 4 months of treatment, there is a transient fall in serum levels of thyroxine (T4) and a rise in thyrotropic hormone (thyroid-stimulating hormone, TSH). After 1 year of treatment, these hormones have generally returned to their baseline. The mechanisms for this are obscure, but lithium inhibits both thyroxine synthesis and its release from the gland (201). Lithium may inhibit endocytosis in the thyroid gland, which results in an accumulation of colloid and thyroglobulin within the follicles, thereby reducing hormone release (202). Thyroid volume... 

Lithium has been known to cause an enlarged or overactive thyroid gland, which is why the client on lithium is always monitored for thyroid functioning (PDR, 2000). Many times a thyroid hormone will be prescribed along with Lithium to restore normal functioning. 

Lithium carbonate has multiple actions on the normal thyroid gland. The main effect of lithium on the thyroid gland is an increase in the retention of iodine, ultimately inhibiting thyroid hormone synthesis. 

Lithium salts have been used as safe adjuncts In the Initial treatment of thyrotoxicosis (75). Lithium Is concentrated by the thyroid gland (76), with a thyrold-to-serum ratio of more than 2 1, suggesting active transport. Lithium Ion Inhibits adenylate cyclase, which forms cAMP. Formed In response to TSH, cAMP Is a stimulator of the processes Involved In thyroid hormone release from the gland. Inhibition of hormone secretion by lithium has proved to be a useful adjunct In treatment of hyperthyroidism (77). 

Lithium accumulates in the thyroid gland and blocks the release of the thyroid hormones by thyroid-stimulating hormone, and can therefore cause clinical hypothyroidism. " The prevalence of hypothyroidism may be higher in women, in middle-age, and in countries with a higher level of nutritional iodine. Potassium iodide temporarily prevents the production of thyroid hormones but, as time goes on, synthesis recommences. Thus, both lithium and iodide ions can depress the production or release of the hormones and therefore have additive hypothyroid effects. 

Early studies showed that lithium is widely distributed in tissues following oral administration or by intraperitoneal or intravenous injection to experimental animals (for review, see Refs. 12 and 17). Thellier et al., in a series of elegant neutron activation experiments using the isotope Li, provided visual localization of lithium in the whole body [18] and in different areas of the brain [8]. Of the soft tissues the pituitary, the thymus, and, most particularly, the thyroid glands have more than the average accumulation of lithium. Bone also appears to accumulate lithium. 

Studies in endocrine organs showed accumulation of lithium in both thyroid and pituitary glands in chronically treated rats [25]. Epithelial cell height is reduced in thyroid gland in cells from lithium patients [26] and from rats [27]. 

A 30-year-old man, who had taken lithium for 16 years for bipolar disorder and long-term ciclosporin and prednisolone after a bone-marrow transplant, developed subacute thyroiditis associated with a diffusely enlarged gland that showed heterogeneous echogenicity, but without a clear relation to lithium (650). 

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