Propylthiouracil

About: Propylthiouracil is a research topic. Over the lifetime, 2181 publications have been published within this topic receiving 46996 citations. The topic is also known as: Thyreostat® & 2,3-dihydro-6-propyl-2-thioxo-4(1H)-pyrimidinone.

The Pharmacokinetics of Propylthiouracil

Abstract: The half-life of propylthiouracil was determined in 7 normal subjects after intravenous injection of 400 mg of the drug. An average value of 77 ± 17 minutes (mean ± S. D.) was found. As the concentration of the drug in the blood declined by a rapid phase followed by a more slow phase a two-compartment model was used for further calculations, and the rate constants between the 2 compartments and the overall elimination constant have been calculated. The same dose of propylthiouracil was later administered per os to the same 7 persons and the plasma concentration was followed to non-measurable values. An average maximum concentration of 9.1 ± 2.5 μg/ml was obtained after a period of 57 ± 22 minutes. The area under the “peroral” curve has been calculated in per cent of the area under the “intravenous” curve. An average value of 77 ± 13 % was found expressing the bioavailability of the drug after oral administration.

Thyrotropin and thyroidal peroxidase activity.

Abstract: In order to investigate the effect of thyrotropin on thyroid peroxidase, changes in the peroxidase activity in response to several in vivo manipulations to change thyroidal iodine metabolism were observed in rats. Most of the peroxidase activity in rat thyroids determined by a guaiacol assay was found in a mitochondrial–microsomal fraction, and the activity was not increased by solubilization of the enzyme with 1% digitonin. Manipulations included the acute administration of 1 USP unit of TSH, 3 mg of propylthiouracil (PTU) and 200 mg of perchlorate (C1O4-), and the chronic administration of 2 USP units of TSH, 3 mg of PTU, 200 mg of CIO4-, 5 ng of triiodothyronine (T3) and T3 plus PTU daily for 7 days. The peroxidase activity per thyroid and per unit of deoxyribonucleic acid (DNA) was not changed by any of the acute manipulations. However, the chronic administration of TSH, PTU and C1O4∼ significantly increased, and T3 and T3 plus PTU significantly decreased the activity. These results suggest that TSH i...

Antineutrophil cytoplasmic antibodies (ANCA)-associated crescentic glomerulonephritis and propylthiouracil therapy.

Abstract: Cutaneous vasculitis is an uncommon complication of propylthiouracil therapy. Although its pathogenesis remains to be established, detection of antineutrophil cytoplasmic antibodies (ANCA) in association with this type of vasculitis has recently been described. We report here 2 patients who developed ANCA-associated crescentic glomerulonephritis without evidence of cutaneous vasculitis during propylthiouracil treatment of hyperthyroidism. Improvement of the renal function and the disappearance of ANCA were correlately found after discontinuation of propylthiouracil and by corticosteroid therapy in both patients.

Thyroid function and thyroid disorders during pregnancy: a review and care pathway.

Abstract: To review the literature on thyroid function and thyroid disorders during pregnancy. A detailed literature research on MEDLINE, Cochrane library, EMBASE, NLH, ClinicalTrials.gov, and Google Scholar databases was done up to January 2018 with restriction to English language about articles regarding thyroid diseases and pregnancy. Thyroid hormone deficiencies are known to be detrimental for the development of the fetus. In particular, the function of the central nervous system might be impaired, causing low intelligence quotient, and mental retardation. Overt and subclinical dysfunctions of the thyroid disease should be treated appropriately in pregnancy, aiming to maintain euthyroidism. Thyroxine (T4) replacement therapy should reduce thyrotropin (TSH) concentration to the recently suggested fixed upper limits of 2.5 mU/l (first and second trimester) and 3.0 mU/l (third trimester). Overt hyperthyroidism during pregnancy is relatively uncommon but needs prompt treatment due to the increased risk of preterm delivery, congenital malformations, and fetal death. The use of antithyroid drug (methimazole, propylthiouracil, carbimazole) is the first choice for treating overt hyperthyroidism, although they are not free of side effects. Subclinical hyperthyroidism tends to be asymptomatic and no pharmacological treatment is usually needed. Gestational transient hyperthyroidism is a self-limited non-autoimmune form of hyperthyroidism with negative antibody against TSH receptors, that is related to hCG-induced thyroid hormone secretion. The vast majority of these patients does not require antithyroid therapy, although administration of low doses of β-blocker may by useful in very symptomatic patients. Normal maternal thyroid function is essential in pregnancy to avoid adverse maternal and fetal outcomes.

High pre-therapy [99mTc]pertechnetate thyroid uptake, thyroid size and thyrostatic drugs: predictive factors of failure in [131I]iodide therapy in Graves' disease.

Abstract: Background and objective Several factors may interfere with the success rate of radioiodine therapy (RIT) in Graves' disease. Our aim was to evaluate, retrospectively, some of these factors in the outcome of RIT. Methods Patient gender, age at diagnosis, ophthalmopathy, disease duration, thyroid size, drug used as clinical treatment, thionamide withdrawal period during RIT preparation, FT 4 , TSH and [ 9 9 m Tc]pertechnetate thyroid uptake prior to RIT were studied as potential interference factors for RIT success. Eighty-two Graves' disease patients were submitted to RIT after thionamide treatment failure. Prior to RIT, 67 patients were receiving methimazole and 15 propylthiouracil. Thirty-three patients received thionamides during RIT; in 49 patients the medication was withdrawn for 2-30 days. [ 9 9 m Tc]pertechnetate thyroid uptake was determined before RIT. Fixed doses of 370 MBq of [ 1 3 1 I]iodide were administered to all patients. Results Eleven patients became euthyroid; 40 became hypothyroid and 31 remained hyperthyroid. There was no association between outcome and age at diagnosis, gender, ophthalmopathy, pre-RIT FT 4 , TSH, antithyroid antibodies or thyrostatic drug. Multiple logistic regression showed higher probability of treatment success in patients with thyroid mass <53g (odds ratio (OR)=8.9), with pre-RIT thyroid uptake <12.5% (OR=4.1) and in patients who withdrew thionamide before RIT (OR=4.9). Conclusions Fixed doses of 370 MBq of radioiodine seem to be practical and effective for treating Graves' disease patients with [ 9 9 m Tc]pertechnetate uptake <12.5% and thyroid mass <53g. This treatment is clearly not recommended for patients with large goitre. In contrast to what could be expected, patients with a high pre-RIT thyroid uptake presented a higher rate of RIT failure.