Liotrix is a mixture of levothyroxine (T4) and liothyronine (T3), which are normal components of human milk. Limited data on exogenous replacement doses of levothyroxine during breastfeeding indicate no adverse effects in infants. No information is available on the use of exogenous liothyronine during breastfeeding. The American Thyroid Association recommends that subclinical and overt hypothyroidism should be treated with levothyroxine in lactating women seeking to breastfeed.[1] Thyroid dosage requirement may be increased in the postpartum period compared to prepregnancy requirements patients with Hashimoto's thyroiditis.[2]

Thyroid hormone disease is common among older adults and is associated with cognitive impairment. However, pathologic correlates are not well understood. We studied pathologic and clinical factors associated with hypothyroidism, the most common manifestation of thyroid disease, in research subjects seen annually for clinical evaluations at U.S. Alzheimer's Disease Centers. Thyroid disease and treatment status were assessed during clinician interviews. Among autopsied subjects, there were 555 participants with treated hypothyroidism and 2146 without known thyroid disease; hypothyroidism was associated with severe atherosclerosis (odds ratio: 1.35; 95% confidence interval: 1.02, 1.79) but not Alzheimer's disease pathologies (amyloid plaques or neurofibrillary tangles). Among participants who did not undergo autopsy (4598 with treated hypothyroidism and 20,945 without known thyroid hormone disease), hypercholesterolemia and cerebrovascular disease (stroke and/or transient ischemic attack) were associated with hypothyroidism, complementing findings in the smaller autopsy sample. This is the first large-scale evaluation of neuropathologic concomitants of hypothyroidism in aged individuals. Clinical hypothyroidism was prevalent (>20% of individuals studied) and was associated with cerebrovascular disease but not Alzheimer's disease-type neuropathology.

The role of the hypothalamic-pituitary-thyroid axis is important in normal skeletal development, gain of bone mass, and regulation of adult bone metabolism. Hypothyroidism in childhood causes delayed bone maturation and growth disturbance and thyroid dysfunction in adult induces altered bone remodeling and an increased risk of bone fracture. Thyroid hormone actions in skeletal cells are mainly mediated by thyroid hormone receptor α (TRα) . The responses to thyroid hormone are regulated by type 2 and 3 iodothyronine deiodinase (DIO2 and DIO3) , which convert prohormone (T4) to active hormone (T3) . Euthyroid status is necessary for the homeostasis of human bone metabolism.

Thyroid hormone lowers serum cholesterol and alters sterol metabolic processes. This laboratory has previously reported increased biliary lipid secretion as an early effect of triiodothyronine (T3) in the rat. To evaluate whether the bile lipid action of T3 is a primary or secondary effect, the isolated-perfused rat liver model was used. Red blood cells in lipid-free buffer were used to perfuse livers of euthyroid and methimazole-hypothyroid rats, as well as hypothyroid rats given T3 at intervals before perfusion. Bile flow was maintained by taurocholate perfusion. Hypothyroid rats had elevated pre-perfusion serum cholesterol compared to euthyroid (107 +/- 4 vs. 65 +/- 2 mg/dl) and decreased biliary cholesterol (0.016 +/- 0.001 vs. 0.031 +/- 0.004 mumol/g liver/h) secretion. Serum cholesterol decreased to euthyroid levels by 18 h after T3, an effect that was prevented by bile duct ligation. Bile cholesterol secretion doubled by 18 h, and reached levels twice euthyroid by 42 h, while phospholipid secretion doubled to levels just above euthyroid. The fourfold increase in biliary cholesterol secretion occurred with lipid-free perfusion and unchanging bile acid uptake or output. It occurred without a fall in hepatic lipoprotein cholesterol secretion. Blockade of cholesterol synthesis with lovastatin failed to alter T3-augmented bile cholesterol secretion. We conclude that T3 induces biliary cholesterol secretion concomitantly with the fall in serum cholesterol. This augmented biliary secretion did not appear to depend upon lipoprotein uptake, increased bile acid transport, or cholesterol synthesis. It did not occur at the expense of hepatic lipoprotein secretion. Facilitated biliary lipid secretion may be a primary effect of T3.

In this paper we report about the actual supply of iodine of women in childbred determining iodine levels in serum and milk of the mothers. No significant differences were found between women without, with treated or with untreated goitre. In early childbred and 4 weeks after birth the iodine in milk amounts to about the half of the maternal serum level and does not further increase with continuation of nursing.

Hypothyroidism may be self-limiting or may progress to thyroid failure, depending on the cause. Thus, diagnosis of the underlying disorder is extremely important. Once the diagnosis is established, the origin and cause of hypothyroidism must be identified. A careful history and physical examination, routine laboratory tests, and demonstration of antithyroid antibodies will ordinarily lead to the correct diagnosis. Self-limited disorders require little or no therapy. Progressive disease is treated with a thyroid hormone preparation. Myxedema coma is an endocrine emergency that requires prompt treatment of both the metabolic complications and any intercurrent illness.

It is reported on a case of chronic insufficiency of the anterior lobe of the pituitary gland after frontobasal fracture of the skull. It is referred to the rareness of traumatically caused hypophyseal endocrine deficiency syndromes and the etiopathogenesis, the differential-diagnostic problem as well as the possibilities of a hormonal substitution therapy is discussed on the basis of the specialized literature.

In connection with the elucidation of the mechanisms of the acute and chronic haemodynamic stress during cardiac overloading, as well as in investigations on the role of neurotransmitter systems in the genesis of myocardial hypertrophy (MH), we carried out a complex of studies involving modelling of MH induced by treatment of rats with isoprenaline (ISO.) and of rabbits with thyreotom (Tri-iodothyronin +L-Thyroxin). With a view to studying some pathogenetic factors participating in the characteristics of the reproduced pathological states, combinations with oxprenolol, atropine, phentolamine (Phent.) and amino-oxyacetic acid (AOAA), which is a GABA-inhibitor, were also applied. The results of the ECG studies performed are the main object of the present article. Marked MH was found in rats injected for 12 days with Iso. in doses of 2 mg/kg, as well as in rabbits which received thyreotom (accompanied with development of arterial hypertension). Considerable functional and morphological damage (with subendocardial fibrous proliferations) were discovered in rats treated with Iso. +Phent. The combinations of oxprenolol and AOAA manifested a protective effect to rabbits with thyrotoxic disturbances. Evident is also the essential role played by the adrenergic mechanisms in MH pathogenesis.

Levothyroxine sodium was estimated from tablet formulations of levothyroxine sodium and liotrix (liothyronine sodium-levothyroxine sodium combination tablet). The procedures consisted of the addition of 3,3-,5-triiodothyronine as the internal standard to the pulverized sample, followed by an acidic butanol extraction, evaporation, and injection onto a muBondapak reversed-phase high-performance liquid chromatographic column. The eluent was methanol-water-phosphoric acid (50:50:0.1), and the effluent was monitored by UV detection at 254 nm. A standard linear calibration curve was obtained for direct standard solutions equivalent to 18-225 micrograms of levothyroxine sodium/tablet. The procedure is sensitive enough for single-tablet analysis. Using this procedure, content uniformity studies were performed on liothyronine sodium tablets, levothyroxine sodium tablets, and liotrix tablets. The procedure also was adapted for conducting dissolution studies on levothyroxine sodium tablets in deionized water using the rotating-paddle method.