Euthyrox

Benign euthyroid goitre & prophylaxis of relapse after surgery. Substitution therapy in hypothyroidism. Concomitant therapy during anti-thyroid medicinal treatment of hyperthyroidism. Suppression therapy in thyroid cancer. 100 mcg: Diagnostic use for thyroid suppression testing.

Benign euthyroid goitre & prophylaxis of relapse after surgery 75-200 mcg daily. Substitution therapy in hypothyroidism Adult Initially 25-50 mcg daily. Maintenance: 100-200 mcg daily. Childn Initially 12.5-50 mcg daily. Maintenance: 100-150 mcg/m² daily. Suppression therapy in thyroid cancer 150-300 mcg daily. Concomitant supplementation during antithyroid drug treatment of hyperthyroidism 50-100 mcg daily. 100 mcg: Diagnostic use for thyroid suppression testing 200 mcg daily for wk 2 & 1 prior to test.

Should be taken on an empty stomach: Take at least 30 min before meals.

Hypersensitivity. Untreated adrenal & pituitary insufficiency; hyperthyroidism or untreated thyrotoxicosis including untreated subclinical (suppressed serum TSH level w/ normal T₃ & T₄ levels) hyperthyroidism. Not to be initiated in patients w/ acute MI, myocarditis & pancarditis. Pregnancy.

Not to be given for wt reduction. Exclude or treat coronary, pituitary & adrenal insufficiency, angina pectoris, arteriosclerosis, HTN & thyroid autonomy before starting therapy or performing thyroid suppression test. Consider dose adjustment if signs of psychotic disorders occur. Avoid in patients w/ coronary insufficiency, heart failure or tachycardiac arrhythmias; frequently check thyroid hormone parameters for drug-induced hyperthyroidism. Determine aetiology of secondary hypothyroidism before thyroid hormone replacement therapy is given. TRH test or suppression scintigram is recommended before treatment initiation if thyroid autonomy is suspected. Avoid supraphysiological serum levothyroxine levels in postmenopausal women w/ hypothyroidism & increased risk of osteoporosis; closely monitor thyroid function. Not recommended in hyperthyroid metabolic states. Close clinical monitoring including lab test during transition to another levothyroxine-containing product due to potential risk of thyroid imbalance. Biotin may interfere w/ thyroid immunoassays based on biotin/streptavidin interaction leading to either falsely decreased or increased test results; patients taking biotin-containing products should inform lab personnel when thyroid function test is requested; use alternative tests not susceptible to biotin interference if available. Risk of increased bone resorption in long-term therapy especially in postmenopausal women on greater than replacement doses or in women receiving suppressive doses. Patients w/ CHD & in those w/ severe or long-existing hypothyroidism. Co-administration w/ orlistat. Lactation. Monitor haemodynamic parameters when therapy is initiated in very low birth wt preterm neonates. Elderly.

Tachycardia, palpitation, cardiac arrhythmias (eg, atrial fibrillation & extrasystoles), angina pectoris, headache, muscular weakness & cramps, flushing, fever, vomiting, menstruation disorders, pseudotumour cerebri, tremor, restlessness, insomnia, hyperhidrosis, wt loss, diarrhoea.

Effect may be influenced by PIs (eg, ritonavir, indinavir, lopinavir); phenytoin. May reduce effect of antidiabetics. May increase risk of haemorrhage (eg, CNS or GI bleeding) w/ coumarin derivatives. Intensified effect w/ salicylates, dicumarol, furosemide, clofibrate. Possible decreased absorption of thyroid hormones w/ PPIs. Reduced control of hypothyroidism when used concomitantly w/ orlistat. Absorption may be decreased w/ sevelamer. Efficacy may be decreased w/ tyrosine kinase inhibitors (eg, imatinib, sunitinib). Absorption may be inhibited by ion exchange resins (eg, cholestyramine or colestipol). Potentially decreased effect w/ Al, Fe & Ca salts. May inhibit the peripheral conversion of T₄-T₃ w/ propylthiouracil, glucocorticoids, β-sympatholytics, iodine-containing contrast media; amiodarone. Decreased efficacy & increased serum TSH level w/ sertraline, chloroquine/proguanil. Increased hepatic clearance by hepatic enzyme induction (eg, barbiturates, carbamazepine). Increased need for levothyroxine in women using oestrogen-containing contraceptives or postmenopausal women under HRT. Decreased intestinal absorption w/ soy-containing compd. Falsely decreased or increased thyroid immunoassay test results w/ biotin.

Thyroid Hormones

H03AA01 - levothyroxine sodium ; Belongs to the class of thyroid hormones.

POM