Thyroid stimulating hormone levels

Li FX, Byrd DM, Deyhle GM, Sesser DE, Skeels MR, Katkowsky SR, Lamm SH (2000) Neonatal thyroid-stimulating hormone level and perchlorate in drinking water. Teratology... 

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

A common mistake is to treat bipolar depression in the same manner that one treats unipolar depression, overlooking the need for a mood stabilizer. In bipolar depression, the first pharmacological intervention should be to start or optimize treatment with a mood stabilizer rather than to start administering an antidepressant medication. In addition, thyroid function should be evaluated, particularly if the patient is taking lithium. Subclinical hypothyroidism, manifested as an increased thyroid-stimulating hormone level and normal triiodothyronine and thyroxine levels, may present as depression in affectively predisposed individuals. In such cases, the addition of thyroid hormones may be beneficial, even if there is no other evidence of hypothyroidism. 

Parle JV, Franklyn JA, Cross KW, Jones SR, Sheppard MC. Thyroxine prescription in the community serum thyroid stimulating hormone level assays as an indicator of undertreatment or overtreatment. Br J Gen Pract 1993 43 107-9. 

Metallic Mercury. A 13-year-old boy exposed to mercury vapors for 2 weeks developed a thyroid enlargement with elevated triiodothyronine, and thyroxine and low thyroid-stimulating hormone levels (Karpathios et al. 1991). Serum-free thyroxine (T4) and the ratio of free thyroxine to free 3,5,3 -triiodo-... 

De Whalley P. Do abnormal thyroid stimulating hormone level values result in treatment changes A study of patients on thyroxine in one general practice. Br J Gen Pract 1995 45 93-95. 

Malathion can disrupt thyroidal activity, in young adult rats, administration of malathion at 60 p,g/rat/day for 21 days resulted in decreased serum T3 and T4 and increased thyroid-stimulating hormone levels (Akhtar et ai, 1996). In tadpole, malathion affects development. A significant delay of growth was observed in tadpoles in water... 

Garwood CL, Van Schepen KA, McDonough RP, Sullivan AL. Increased thyroid-stimulating hormone levels associated with concomitant administration of levothyroxine and raloxifene. 

Discuss the relationship between serum thyroid-stimulating hormone (TSH) levels and primary thyroid disease and the advantages for the use of TSH levels over other tests such as serum T4 (thyroxine) and T3 (triiodothyroinine) levels. 

O In most patients with thyroid hormone disorders, the measurement of a serum thyroid-stimulating hormone (TSH) level is adequate for the diagnosis of hypothyroidism and hyperthyroidism. The target TSH for most patients being treated for thyroid disorders should be the mean normal value of 1.4 milliunits/L or 1.4 microunits/mL (target range 0.5-2.5 milliunits/L or 0.5-2.5 microunits/mL). 

Cannabimimetics are also shown to affect reproductive and metabolic functions indirectly by hormonal modulation through the hypothalamic and pituitary regulatory centers. They are found to reduce serum levels of the luteinizing hormone, prolactin, growth hormone, and thyroid-stimulating hormone, and to increase corticotropin (Murphy, 1998). 

Li+ has been reported to affect virtually every component of the endocrine system to some extent however any resulting clinical manifestations are very rare [169]. Although these influences do not appear to be related to its mechanism of action in manic-depression, some are involved in the side effects experienced by Li+-treated patients. Apart from elevated levels of thyroid stimulating hormone (TSH), Li+ does not appear to affect the basal levels of hormones significantly however some hormone responses are reported to be altered by Li+ treatment of bipolar patients [170]. Neuronal activity stimulates the adrenal medulla to release norepinephrine and epinephrine into the blood and, consequently, the plasma from people with mania and depression shows increased levels of both neurotransmitters [171]. 

We have already noted (p. 92) that the blood levels of the thyreotropic hormone (thyroid stimulating hormone TSH) appear to vary by a factor of 10 or more. This is one of the better-known pituitary hormones since it has been obtained in nearly pure form. 

Mandatory studies Complete blood count Blood electrolytes Liver enzymes Urinalysis Vitamin B,2 level Folate level Syphilis (RPR/VDRL) Thyroid-stimulating hormone (TSH) Brain scan (CT or MRI) Electrocardiograph (EKG)... 

Many of the adverse effects of lithium can be ascribed to the action of lithium on adenylate cyclase, the key enz)nne that links many hormones and neurotransmitters with their intracellular actions. Thus antidiuretic hormone and thyroid-stimulating-hormone-sensitive adenylate cyclases are inhibited by therapeutic concentrations of the drug, which frequently leads to enhanced diuresis, h)rpoth)n oidism and even goitre. Aldosterone synthesis is increased following chronic lithium treatment and is probably a secondary consequence of the enhanced diuresis caused by the inhibition of antidiuretic-hormone-sensitive adenylate cyclase in the kidney. There is also evidence that chronic lithium treatment causes an increase in serum parathyroid hormone levels and, with this, a rise in calcium and magnesium concentrations. A decrease in plasma phosphate and in bone mineralization can also be attributed to the effects of the drug on parathyroid activity. Whether these changes are of any clinical consequence is unclear. 

Secondary hypothyroidism, or pituitary hypothyroidism, is the consequence of impaired thyroid-stimulating hormone (TSH) secretion and is less common than primary hypothyroidism. It may result from any of the causes of hypopituitarism (e.g., pituitary tumor, postpartum pituitary necrosis, trauma). Patients with secondary hypothyroidism exhibit undetectable or inappropriately low serum TSH concentrations. In secondary hypothyroidism, a normal thyroid gland lacks the normal level of TSH stimulation necessary to synthesize and secrete thyroid hormones. Such patients usually also have impaired secretion of TSH in response to exogenous thyrotropin-releasing hormone (TRH) administration. 

Her weight is 136 lb (61.8 kg), an increase of 10 lb (4.5 kg) in the last year. Her thyroid gland is not palpable and her reflexes are delayed. Laboratory findings include a thyroid-stimulating hormone (TSH) level of 14.9 pIU/mL and a free thyroxine level of 8 pmol/L. Evaluate the management of her past history of hyperthyroidism. Identify the available treatment options for control of her current thyroid status. 

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