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Unithroid Generic Name & Formulations
Legal Class
Rx
General Description
Levothyroxine sodium 25mcg, 50mcg (dye-free), 75mcg, 88mcg, 100mcg, 112mcg, 125mcg, 137mcg, 150mcg, 175mcg, 200mcg, 300mcg; scored tabs.
Pharmacological Class
T4 (synthetic).
How Supplied
Tabs—100
Manufacturer
Unithroid Indications
Indications
Adjunct to surgery and radioiodine therapy in the management of thyrotropin-dependent well-differentiated thyroid cancer.
Limitations of Use
Not for the suppression of benign thyroid nodules and nontoxic diffuse goiter in iodine-sufficient patients. Not for the treatment of hypothyroidism during the recovery phase of subacute thyroiditis.
Unithroid Dosage and Administration
Adults and Children
Take in AM on empty stomach. Target TSH levels within desired therapeutic range for TSH suppression. Individualize. Doses >2mcg/kg/day may be required.
Unithroid Contraindications
Contraindications
Uncorrected adrenal insufficiency.
Unithroid Boxed Warnings
Boxed Warning
Not for treatment of obesity for weight loss.
Unithroid Warnings/Precautions
Warnings/Precautions
Underlying cardiovascular disease. Monitor for cardiac arrhythmias during surgery in those with coronary artery disease. Reduce or withhold dose for 1 week if cardiac symptoms develop or worsen; restart at lower dose. Myxedema coma: use IV levothyroxine. Adults: Monitor TSH 6–8 weeks after dose change then every 6–12 months when stable. Peds: Monitor TSH and total or free-T4 at 2 and 4 weeks after initiation, 2 weeks after dose change then every 3–12 months thereafter. Correct adrenal insufficiency before initiation. Increased sensitivity in severe hypothyroidism. Diabetes; monitor glycemic control. Increased bone resorption and decreased BMD (esp. in post-menopausal women). Use lowest effective dose. Elderly. Pregnancy: monitor TSH/free-T4 at least every trimester; adjust dose and do not discontinue (see full labeling). Nursing mothers.
Unithroid Pharmacokinetics
See Literature
Unithroid Interactions
Interactions
See full labeling. Absorption reduced by some foods (eg, soy flour, cottonseed meal, walnuts, fiber, grapefruit juice), aluminum and magnesium hydroxide, simethicone, proton pump inhibitors, iron, sucralfate; monitor. Give at least 4hrs apart from calcium carbonate, ferrous sulfate, bile acid sequestrants (eg, colesevelam, cholestyramine, colestipol), ion exchange resins (eg, kayexalate, sevelamer). Thyroid levels may be affected by clofibrate, estrogens, methadone, 5-fluorouracil, mitotane, tamoxifen, androgens, anabolic steroids, asparaginase, glucocorticoids, nicotinic acid (slow-release), salicylates (>2g/day), β-blockers (eg, propranolol), glucocorticoids, amiodarone. Monitor thyroid parameters with concomitant carbamazepine, furosemide (>80mg IV), heparin, hydantoins, NSAIDs. Potentiates, and is potentiated by, tri- and tetracyclic antidepressants. Concomitant sympathomimetics; monitor for coronary insufficiency. Antagonized by phenobarbital, rifampin, sertraline. Antagonizes digitalis glycosides. Marked hypertension and tachycardia with ketamine. Hypothyroidism risk with concomitant tyrosine kinase inhibitors (eg, imatinib). Monitor with oral anticoagulants, antidiabetic agents, orlistat.
Unithroid Adverse Reactions
Adverse Reactions
Arrhythmias, myocardial infarction, dyspnea, muscle spasm, headache, nervousness, irritability, insomnia, tremors, muscle weakness, increased appetite, weight loss, diarrhea, heat intolerance, menstrual irregularities, skin rash; seizures (rare); Children: pseudotumor cerebri, slipped capital femoral epiphysis.
Unithroid Clinical Trials
See Literature
Unithroid Note
Not Applicable
Unithroid Patient Counseling
See Literature
Unithroid Generic Name & Formulations
Legal Class
Rx
General Description
Levothyroxine sodium 25mcg, 50mcg (dye-free), 75mcg, 88mcg, 100mcg, 112mcg, 125mcg, 137mcg, 150mcg, 175mcg, 200mcg, 300mcg; scored tabs.
Pharmacological Class
T4 (synthetic).
How Supplied
Tabs—100
Manufacturer
Unithroid Indications
Indications
Hypothyroidism.
Limitations of Use
Not for the suppression of benign thyroid nodules and nontoxic diffuse goiter in iodine-sufficient patients. Not for the treatment of hypothyroidism during the recovery phase of subacute thyroiditis.
Unithroid Dosage and Administration
Adult
Take in AM on empty stomach. Individualize. Titrate as needed until patient is euthyroid and serum TSH normalized. Primary hypothyroidism: 1.6mcg/kg/day; titrate in increments of 12.5–25mcg every 4–6 weeks. Usual max 200mcg/day. Elderly or underlying cardiac disease: initially 12.5–25mcg once daily; titrate every 6–8 weeks. Severe hypothyroidism: initially 12.5–25mcg once daily; titrate in increments of 12.5–25mcg every 2–4 weeks. Secondary or tertiary hypothyroidism, pregnancy: see full labeling.
Children
Take in AM on empty stomach. May crush tabs and mix in 5–10mL water. Individualize. Congenital or acquired hypothyroidism: 0–3mos: 10–15mcg/kg/day; 3–6mos: 8–10mcg/kg/day; 6–12mos: 6–8mcg/kg/day; 1–5yrs: 5–6mcg/kg/day; 6–12yrs: 4–5mcg/kg/day; >12yrs but growth and puberty incomplete: 2–3mcg/kg/day; growth and puberty complete: 1.6mcg/kg/day. Newborns at risk for cardiac failure: consider lower initial dose; titrate every 4–6 weeks as needed. Risk for hyperactivity: initially ¼ full replacement dose; titrate by ¼ dose weekly until full dose reached.
Unithroid Contraindications
Contraindications
Uncorrected adrenal insufficiency.
Unithroid Boxed Warnings
Boxed Warning
Not for treatment of obesity for weight loss.
Unithroid Warnings/Precautions
Warnings/Precautions
Underlying cardiovascular disease. Monitor for cardiac arrhythmias during surgery in those with coronary artery disease. Reduce or withhold dose for 1 week if cardiac symptoms develop or worsen; restart at lower dose. Myxedema coma: use IV levothyroxine. Adults: Monitor TSH 6–8 weeks after dose change then every 6–12 months when stable. Peds: Monitor TSH and total or free-T4 at 2 and 4 weeks after initiation, 2 weeks after dose change then every 3–12 months thereafter. Correct adrenal insufficiency before initiation. Increased sensitivity in severe hypothyroidism. Diabetes; monitor glycemic control. Increased bone resorption and decreased BMD (esp. in post-menopausal women). Use lowest effective dose. Elderly. Pregnancy: monitor TSH/free-T4 at least every trimester; adjust dose and do not discontinue (see full labeling). Nursing mothers.
Unithroid Pharmacokinetics
See Literature
Unithroid Interactions
Interactions
See full labeling. Absorption reduced by some foods (eg, soy flour, cottonseed meal, walnuts, fiber, grapefruit juice), aluminum and magnesium hydroxide, simethicone, proton pump inhibitors, iron, sucralfate; monitor. Give at least 4hrs apart from calcium carbonate, ferrous sulfate, bile acid sequestrants (eg, colesevelam, cholestyramine, colestipol), ion exchange resins (eg, kayexalate, sevelamer). Thyroid levels may be affected by clofibrate, estrogens, methadone, 5-fluorouracil, mitotane, tamoxifen, androgens, anabolic steroids, asparaginase, glucocorticoids, nicotinic acid (slow-release), salicylates (>2g/day), β-blockers (eg, propranolol), glucocorticoids, amiodarone. Monitor thyroid parameters with concomitant carbamazepine, furosemide (>80mg IV), heparin, hydantoins, NSAIDs. Potentiates, and is potentiated by, tri- and tetracyclic antidepressants. Concomitant sympathomimetics; monitor for coronary insufficiency. Antagonized by phenobarbital, rifampin, sertraline. Antagonizes digitalis glycosides. Marked hypertension and tachycardia with ketamine. Hypothyroidism risk with concomitant tyrosine kinase inhibitors (eg, imatinib). Monitor with oral anticoagulants, antidiabetic agents, orlistat.
Unithroid Adverse Reactions
Adverse Reactions
Arrhythmias, myocardial infarction, dyspnea, muscle spasm, headache, nervousness, irritability, insomnia, tremors, muscle weakness, increased appetite, weight loss, diarrhea, heat intolerance, menstrual irregularities, skin rash; seizures (rare); Children: pseudotumor cerebri, slipped capital femoral epiphysis.
Unithroid Clinical Trials
See Literature
Unithroid Note
Not Applicable
Unithroid Patient Counseling
See Literature
