Goiter antithyroid drugs

Both the thiouracils and thioimidazoles readily cross the placenta and can cause fetal hypothyroidism, resulting in a slight delay in neurological or bone maturation. Various degrees of goiter have also been observed, even to the extent of severe tracheal compression and death. Antithyroid drug dosage should therefore be reduced to the minimum required to maintain a euthyroid state without supplementation of levothyroxine (93). 

The antithyroid drugs should not be used in patients with a large intrathoracic goiter, which can further increase in size (111). 

Refetoff S, Ochi Y, Selenkow HA, Rosenfield RL. Neonatal hypothyroidism and goiter in one infant of each of two sets of twins due to maternal therapy with antithyroid drugs. J Pediatr 1974 85(2) 240-4. 

The clinical, biochemical, and thyroid imaging characteristics of thyrotoxicosis resulting from interferon alfa treatment have been retrospectively analysed from data on 10 of 321 patients with chronic hepatitis (75 with chronic hepatitis B and 246 with chronic hepatitis C) who developed biochemical thyrotoxicosis (505). Seven patients had symptomatic disorders, but none had ocular symptoms or a palpable goiter. Six had features of Graves disease that required interferon alfa withdrawal in four and prolonged treatment with antithyroid drugs in all six. Three presented with transient thyrotoxicosis that... 

Antithyroid Drugs. Congenital goiter and neonatal hypothyroidism may occur if thiouracil drugs are administered during pregnancy [12]. 

Control of hyperthyroidism usually is associated with a decrease in goiter size, but if the thyroid enlarges, hypothyroidism probably has been induced. When this occurs, the dose of the antithyroid drug should be significantly decreased and/or levothyroxine can be added once hypothyroidism is confirmed by laboratory testing. 

The main use of antithyroid drugs in toxic adenoma and toxic multinodular goiter is therefore to attain a euthyroid state before the patient may undergo other modes of therapy. Another use is to block iodine uptake prior to the exposure to radiographic contrast agents in patients at risk of iodine-induced hyperthyroidism. 

The choice of treatment is discussed by the specialist and the patient. In the absence of one of the indications for surgery, we would suggest radioiodine treatment as the first choice. In case of overt hyperthyroidism, pretreatment with antithyroid drugs may be necessary. Optimum treatment modalities including the presence of a suppressed TSH in toxic adenoma or multinodular goiter should be established. On the one hand, patient s fears regarding radiation exposure and, on the other hand, possible surgical complication often infiuence the decision and have to be addressed. 

The Ts compensatory phenomenon has been noted in (1) iodopenic endemic goiter (D4, K8, P3) (2) dyshormonogenetic goiter (Fll, G8, N4) (3) euthyroid endocrine exophthalmos (H16) (4) incipient thyroid failure associated with autoimmune thyroid disease (E7) (5) thyrotoxicosis treated either with antithyroid drugs or with (B5, S23, W8). 

Toxic goiter— The most commonly used treatments for hyperthyroidism are antithyroid drugs which block the synthesis of thyroid hormones, surgical removal of part of the thyroid gland, and therapy with radioiodine which destroys the cells of the thyroid. It is sometimes necessary to balance these treatments with oral doses of thyroid hormones in order to prevent the effects of hypothyroidism. Administration of large excesses of iodine for the purfXKe of hormone synthesis is no longer used since the effect is only temporary. 

Dr. Dumont has mentioned that dogs seem never to develop a goiter, in spite of low iodine conditions or administration of antithyroid drugs. Dr. Ermans also mentioned that there are people who adapt better than others to iodine deficiency and hence do not develop goiter. My question therefore is whether this observation both in animals and humans corresponds to different iodine kinetics or to some abnormality at the level of the thyroid follicular cell ... 

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