WordNet

having the effect of counteracting excessive thyroid activity; "antithyroid drugs"

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2012/09/12 14:17:55」(JST)

wiki en

[Wiki en表示]

An antithyroid agent is a hormone antagonist acting upon thyroid hormones.

The main antithyroid drugs are carbimazole (in the UK), methimazole (in the US), and propylthiouracil/PTU. A less common antithyrioid agent is potassium perchlorate.

Mechanism of action

Carbimazole, methimazole and propylthiouracil inhibit the enzyme thyroperoxidase, and thereby block the binding of iodine and coupling of iodotyrosines, in turn causing reduced synthesis of thyroid hormones.

Adverse effects

The most dangerous side-effect is agranulocytosis (1/250, more in PTU); this is an idiosyncratic reaction which generally resolves on cessation of drug. It occurs in about 0.2 to 0.3% of cases treated with antithyroid drugs.^[1] Others include granulocytopenia (dose dependent, which improves on cessation of the drug) and aplastic anemia, and for propylthiouracil severe, fulminant liver failure.^[2] Patients on these medications should see a doctor if they develop sore throat or fever.

The most common side effects are rash and peripheral neuritis. These drugs also cross the placenta and are secreted in breast milk. Lugol's iodine is used to block hormone synthesis before surgery.

Usage in Graves' disease

Further information: Graves' disease

In Graves' disease, treatment with antithyroid medications must be given for six months to two years, in order to be effective. Even then, upon cessation of the drugs, the hyperthyroid state may recur. Side effects of the antithyroid medications include a potentially fatal reduction in the level of white blood cells.

A randomized control trial testing single dose treatment for Graves' found methimazole achieved euthyroid state more effectively after 12 weeks than did propylthyouracil (77.1% on methimazole 15 mg vs 19.4% in the propylthiouracil 150 mg groups).^[3] But generally both drugs are considered equivalent.

A study has shown no difference in outcome for adding thyroxine to antithyroid medication and continuing thyroxine versus placebo after antithyroid medication withdrawal. However, two markers were found that can help predict the risk of recurrence. These two markers are an elevated level of thyroid stimulating hormone receptor antibodies (TSHR-Ab) and smoking. A positive TSHR-Ab at the end of antithyroid drug treatment increases the risk of recurrence to 90% (sensitivity 39%, specificity 98%), a negative TSHR-Ab at the end of antithyroid drug treatment is associated with a 78% chance of remaining in remission. Smoking was shown to have an impact independent to a positive TSHR-Ab.^[4]

References

^ Zambrana, J.; Zambrana, F.; Neto, F.; Gonçalves, A.; Zambrana, F.; Ushirohira, J. (2005). "Agranulocytosis with tonsillitis associated with methimazole therapy". Brazilian journal of otorhinolaryngology 71 (3): 374–377. PMID 16446945. edit [1]
^ Bahn RS, Burch HS, Cooper DS, Garber JR, Greenlee CM, Klein IL, Laurberg P, McDougall IR et al. (July 2009). "The Role of Propylthiouracil in the Management of Graves' Disease in Adults: report of a meeting jointly sponsored by the American Thyroid Association and the Food and Drug Administration.". Thyroid : official journal of the American Thyroid Association 19 (7): 673–4. doi:10.1089/thy.2009.0169. PMID 19583480. http://www.liebertonline.com/doi/pdf/10.1089/thy.2009.0169.
^ Homsanit M, Sriussadaporn S, Vannasaeng S, Peerapatdit T, Nitiyanant W, Vichayanrat A (2001). "Efficacy of single daily dosage of methimazole vs. propylthiouracil in the induction of euthyroidism". Clin. Endocrinol. (Oxf) 54 (3): 385–90. doi:10.1046/j.1365-2265.2001.01239.x. PMID 11298092.
^ Glinoer D, de Nayer P, Bex M (2001). "Effects of l-thyroxine administration, TSH-receptor antibodies and smoking on the risk of recurrence in Graves' hyperthyroidism treated with antithyroid drugs: a double-blind prospective randomized study". Eur. J. Endocrinol. 144 (5): 475–83. doi:10.1530/eje.0.1440475. PMID 11331213.

External links

Antithyroid+agents at the US National Library of Medicine Medical Subject Headings (MeSH)

This hormonal preparation article is a stub. You can help Wikipedia by expanding it.

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 甲状腺機能の臨床検査評価 laboratory assessment of thyroid function
2. 患者情報：抗甲状腺薬（詳細） antithyroid drugs beyond the basics
3. 小児および思春期におけるグレーヴス病の治療および予後 treatment and prognosis of graves disease in children and adolescents
4. 橋本脳症 hashimoto encephalopathy
5. 小児および思春期における後天性甲状腺機能低下症 acquired hypothyroidism in childhood and adolescence

English Journal

The feasibility of low-dose oral lithium therapy and its effect on thyroidal radioiodine uptake, retention, and hormonal parameters in various subcategories of hyperthyroid patients: a pilot study.

Chouhan A1, Abhyankar A, Basu S.
Nuclear medicine communications.Nucl Med Commun.2016 Jan;37(1):74-8. doi: 10.1097/MNM.0000000000000414.
BACKGROUND: Radioactive iodine (I) (RAI) is used widely for the treatment of hyperthyroidism either as a first-line treatment or following relapse after antithyroid drug treatment. Intrathyroidal retention of RAI is considered an important determinant of its effectiveness, which is believed to be pr
PMID 26465804

Protective effects of 5,7,4'-trihydroxy-6,3'dimethoxy-flavone 5-O-α-l-rhamnopyranoside, isolated from Annona squamosa leaves in thyrotoxicosis and in hepatic lipid peroxidation in rats.

Panda S1, Kar A1.
Bioorganic & medicinal chemistry letters.Bioorg Med Chem Lett.2015 Dec 15;25(24):5726-8. doi: 10.1016/j.bmcl.2015.10.090. Epub 2015 Oct 30.
Hitherto unknown protective effects of 5,7,4'-trihydroxy-6,3'dimethoxy-flavone 5-O-α-l-rhamnopyranoside (THDMF-Rha); isolated from Annona squamosa leaves were evaluated in l-thyroxine (l-T4)-induced thyrotoxicosis in rats. Administration of l-T4 at 500μg/kg body weight for 12days increased the lev
PMID 26547692

The impact of the presence of antithyroid antibodies on pregnancy outcome following intracytoplasmatic sperm injection-ICSI and embryo transfer in women with normal thyreotropine levels.

Łukaszuk K1,2,3, Kunicki M4, Kulwikowska P1, Liss J2, Pastuszek E1,2, Jaszczołt M5, Męczekalski B6, Skowroński K7.
Journal of endocrinological investigation.J Endocrinol Invest.2015 Dec;38(12):1335-43. doi: 10.1007/s40618-015-0377-5. Epub 2015 Aug 18.
PURPOSE: The aim of our study was to investigate the impact of anti-thyroid peroxidase antibodies (Anti-TPO) on pregnancy outcome following the in vitro fertilization and embryo transfer (IVF-ET) in general groups and in subgroups divided according to AMH level and age.METHODS: A total of 114 patien
PMID 26280321

Japanese Journal

Urinary iodine concentrations of pregnant women in Ukraine

Sekitani Yui,Hayashida Naomi,Takahashi Jumpei,Kozlovsky Alexander A.,Rudnitskiy Stanislav,Petrova Anjelika,Gutevych Oleksandr K.,Chorniy Sergiy A.,Yamashita Shunichi,Takamura Noboru
Clinical Chemistry and Laboratory Medicine 51(4), 811-816, 2013-04
… UI concentration, thyroid-stimulating hormone (TSH), antithyroglobulin antibodies (TGAb), and antithyroid peroxidase antibodies (TPOAb) were measured. …
NAID 120005367569