Adult Dosing

Thyroid hormone replacement

• With low risk of coronary artery disease: 1.7 mcg/kg PO qd. Max: 300 mcg/day. It is often advisable in such patients to start at 50 mcg/day and titrate dose up q2-4 wks to minimize side effects
• With cardiovascular disease: Start at 25-50 mcg PO qd. Gradually increase daily dose by 12.5-25 mcg q6-8 wks until the patient is euthyroid and TSH levels are normal
• Elderly patients with cardiac disease: Start at 12.5-25 mcg PO qd. Gradually increase daily dose by 12.5-25 mcg q4-6 wks until the patient is euthyroid and TSH levels are normal
• Severe hypothyroidism: Start at 12.5 to 25 mcg PO qd. Gradually increase daily dose by 25 mcg q2-4 wks until the patient is euthyroid and TSH levels are normal

Pituitary TSH suppression, in thyrotropin-dependent well-differentiated thyroid cancer

• TSH suppression to less than 0.1 mU/L requires > 2 mcg/kg/day

Pediatric Dosing

Thyroid hormone replacement

Child (congenital or acquired hypothyroidism )

• 0-3 months: 10-15 mcg/kg PO qd
• 3-6 months: 8-10 mcg/kg PO qd
• 6-12 months: 6-8 mcg/kg PO qd
• 1-5 yrs: 5-6 mcg/kg PO qd
• 6-12 yrs: 4-5 mcg/kg PO qd
• > 12 yrs:
• Growth and puberty incomplete: 2-3 mcg/kg PO qd
• Growth and puberty complete: 1.7 mcg/kg PO qd

[Outline]

• Adult Dosing
• Pediatric Dosing

• As replacement or supplemental therapy in thyroidal, pituitary, hypothalamic and subclinical hypothyroidism
• Treatment or prevention of various types of euthyroid goiters including thyroid nodules, subacute or chronic lymphocytic thyroiditis (Hashimoto’s thyroiditis) and multinodular goiter
• Adjunct to surgery and radioiodine therapy in the management of thyrotropin-dependent well-differentiated thyroid cancer

• Hypersensitivity to any of the ingredients of the product
• Untreated subclinical (suppressed serum TSH level with normal T3 and T4 levels)
• Overt thyrotoxicosis of any etiology
• Acute myocardial infarction
• Uncorrected adrenal insufficiency

• Avoid using thyroid hormones either alone or with other therapeutic agents for the treatment of obesity or for weight loss. Doses within the range of daily hormonal requirements are ineffective in euthyroid patients for weight reduction. Serious or even life threatening manifestations of toxicity have occurred at higher doses particularly when given in association with sympathomimetic amines such as those used for their anorectic effects

Renal Dose Adjustment

• Renal impairment: Dose adjustments not defined

Hepatic Dose Adjustment

• Hepatic impairment: Dose adjustments not defined

• Avoid using thyroid hormones either alone or with other therapeutic agents for the treatment of obesity or for weight loss. Doses within the range of daily hormonal requirements are ineffective in euthyroid patients for weight reduction. Serious or even life threatening manifestations of toxicity have occurred at higher doses particularly when given in association with sympathomimetic amines such as those used for their anorectic effects [US Black Box Warning]
• Avoid using in the treatment of male or female infertility unless this condition is associated with hypothyroidism
• Therapy is contraindicated in patients with nontoxic diffuse goiter or nodular thyroid disease, particularly in the elderly or in those with underlying cardiovascular disease, if the serum TSH level is already suppressed, as risk due to precipitation of overt thyrotoxicosis exists
• If the serum TSH levels are not suppressed, use therapy with caution in conjunction with careful monitoring of thyroid function for evidence of hyperthyroidism and also monitor for potential associated adverse cardiovascular signs and symptoms of hyperthyroidis
• Levothyroxine exhibits a narrow therapeutic index. Carefully perform dosage titration to avoid the consequences of over-or under-treatment for treating any indication. Such consequences include effects on growth and development, cardiovascular function, bone metabolism, reproductive function, cognitive function, emotional state, gastrointestinal function, and on glucose and lipid metabolism
• As many drugs interact with this drug, dose adjustments are necessary to maintain therapeutic response
• Long-term therapy can decrease bone mineral density. Post-menopausal women and those women who are receiving suppressive doses of levothyroxine sodium are prone to increased bone resorption resulting in decreased bone mineral density
• Administer minimum dose necessary to achieve the desired clinical and biochemical response
• On developing or worsening of cardiac symptoms, reduce or withhold the dose for one week, and then cautiously restart at a lower dose
• Overtreatment leads to adverse cardiovascular effects such as an increase in heart rate, cardiac wall thickness, and cardiac contractility and may precipitate angina or arrhythmias
• Closely monitor patients with coronary artery disease during surgical procedures since the possibility of precipitating cardiac arrhythmias may be greater in those treated with levothyroxine
• Concurrent administration of levothyroxine and sympathomimetic agents to patients with coronary artery disease precipitates coronary insufficiency
• Avoid administration If the serum TSH is already suppressed
• Consider additional hypothalamic/pituitary hormone deficiencies in patients with secondary or tertiary hypothyroidism and, if diagnosed, treat appropriately
• Occasions of chronic autoimmune thyroiditis have occurred in association with other autoimmune disorders such as adrenal insufficiency, pernicious anemia, and insulin-dependent diabetes mellitus
• Treat patients with concomitant adrenal insufficiency with replacement glucocorticoids prior to initiation of therapy; as failure to do so might precipitate an acute adrenal crisis due to increased metabolic clearance of glucocorticoids by thyroid hormone
• Upward adjustments of antidiabetic therapeutic regimens may be required in patients with diabetes mellitus when treated with levothyroxine
• Infants with congenital hypothyroidism are at increased risk for other congenital anomalies, with cardiovascular anomalies (pulmonary stenosis, atrial septal defect, and ventricular septal defect) being the most common
• Monitor ECG, cardiac overload closely during 1st 2wk of treatment in infants

Cautions: Use cautiously in:

• Cardiovascular disorders
• Diabetes mellitus
• Nontoxic diffuse goiter
• Nodular thyroid disease
• Younger individuals
• Geriatrics

Levo-T, Levothroid, Levoxyl, Synthroid, Tirosint, Unithroid interacts with :

	Antacids
	Carafate
	Cholestyramine
	Colesevelam
	Colestid
	Colestipol
	Fosrenol
	Iron Products
	Lanthanum Carbonate
	Locholest
	Locholest Light
	Prevalite
	Questran
	Questran Light
	Renagel
	Renvela
	Sevelamer
	Sucralfate
	Welchol

Pregnancy Category:A

Breastfeeding: Levothyroxine (T4) is a normally present in human milk. Limited literature on exogenous replacement doses of levothyroxine during breastfeeding indicates no adverse effects in infants. If levothyroxine is required by the mother, breastfeeding does not need to be discontinued. Levothyroxine dosage requirement may be increased in the postpartum period compared to pre-pregnancy requirements in patients with Hashimoto's thyroiditis. This drug is compatible with, and is considered to be safe in breastfeeding. Effects of exogenous thyroid hormone administration to mothers on their infant have not been reported. This information based upon data from AAP Policy Guidelines (available at http://aappolicy.aappublications.org/cgi/content/full/pediatrics;108/3/776) and based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 27 January 2011). Adequate replacement doses of levothyroxine are generally needed to maintain normal lactation. Manufacturer advises caution.

• CV: Palpitations, tachycardia, arrhythmias, increased pulse and blood pressure, heart failure, angina, myocardial infarction, cardiac arrest
• ENDO: Decreased bone mineral density
• GU: Menstrual irregularities, diaphoresis, impaired fertility, pseudotumor cerebri , craniosynostosis, premature epiphyseal closure
• CNS: Headache, seizures, hyperactivity, nervousness, anxiety, irritability, emotional lability, insomnia
• METABOLIC: Increased appetite, weight loss, heat intolerance
• MUSC: Tremors, muscle weakness
• GI: Diarrhea, vomiting, abdominal cramps, elevations in liver function tests
• DERM : Hair loss, flushing, excessive sweating
• RESP: Dyspnea
• MISC: Fatigue, fever

• Thyroid hormone; controls DNA transcription and protein synthesis, regulates multiple metabolic processes, plays an essential role in normal growth and development, and normal maturation of the central nervous system and bone
• Absorption: bioavailability 40-80%
• Metabolized primarily by liver; kidney, tissues; CYP450: Unknown
• Excreted in urine, feces
• Half-life: 6-7 days (euthyroid), 3-4 days (hyperthyroid), 9-10 days (hypothyroid)

US Trade Name(s)

• Levo-T
• Levothroid
• Levoxyl
• Synthroid
• Unithroid
• Tirosint

US Availability

levothyroxine (generic)

• TABS: 25, 50, 75, 88, 100, 112, 125, 137, 150, 175, 200, 300 mcg

Levo-T, Levothroid, Synthroid, Unithroid

• TABS: 25, 50, 75, 88, 100, 112, 125, 137, 150, 175, 200, 300 mcg

Levoxyl

• TABS: 25, 50, 75, 88, 100, 112, 125, 137, 150, 175, 200 mcg

Tirosint

• CAPS: 13, 25, 50, 75, 88, 100, 112, 125, 137, 150 mcg

Canadian Trade Name(s)

• Eltroxin
• Euthyrox
• Synthroid

Canadian Availability

Eltroxin

• TABS: 50, 100, 150, 200, 300 mcg

Euthyrox, Synthroid

• TABS: 25, 50, 75, 88, 100, 112, 125, 137, 150, 175, 200, 300 mcg

UK Trade Name(s)

• Eltroxin
• Evotrox

UK Availability

Levothyroxine (generic)

• TABS: 25, 50, 100 mcg

Eltroxin

• TABS: 25, 50, 100 mcg

Evotrox

• SOLN: 25 mcg/5 mL
• SOLN: 50 mcg/5 mL
• SOLN: 100 mcg/5 mL

Australian Trade Name(s)

• Eutrosig
• Oroxine

Australian Availability

Eutrosig, Oroxine

• TABS: 50, 75, 100, 200 mcg

[Outline]

Endocrine/Metabolic

Thyroid Drugs

Pricing data from www.DrugStore.com in U.S.A.

• Levoxyl 25 MCG TABS [Bottle] (KING PHARMA)
  30 mcg = $20.99
  90 mcg = $39.97
• Levoxyl 88 MCG TABS [Bottle] (KING PHARMA)
  30 mcg = $20.99
  90 mcg = $41.97
• Tirosint 75 MCG CAPS [Box] (AKRIMAX PHARMACEUTICALS)
  28 mcg = $33.99
  84 mcg = $80.97
• Unithroid 112 MCG TABS [Bottle] (LANNETT)
  30 mcg = $19.99
  90 mcg = $39.97
• Tirosint 125 MCG CAPS [Box] (AKRIMAX PHARMACEUTICALS)
  28 mcg = $29.66
  84 mcg = $69.97
• Levoxyl 75 MCG TABS [Bottle] (KING PHARMA)
  30 mcg = $21.99
  90 mcg = $41.97
• Unithroid 100 MCG TABS [Bottle] (LANNETT)
  30 mcg = $17.99
  90 mcg = $35.97
• Tirosint 137 MCG CAPS [Box] (AKRIMAX PHARMACEUTICALS)
  28 mcg = $31.99
  56 mcg = $53.97
• Levothyroxine Sodium 88 MCG TABS [Bottle] (MYLAN)
  30 mcg = $14.99
  90 mcg = $29.97
• Levoxyl 50 MCG TABS [Bottle] (KING PHARMA)
  30 mcg = $22.99
  60 mcg = $34.97
• Unithroid 75 MCG TABS [Bottle] (LANNETT)
  30 mcg = $18.99
  90 mcg = $35.97
• Levothroid 300 MCG TABS [Bottle] (FOREST)
  30 mcg = $20.99
  90 mcg = $47.98
• Synthroid 100 MCG TABS [Bottle] (ABBOTT)
  30 mcg = $28.99
  90 mcg = $64.97
• Levoxyl 125 MCG TABS [Bottle] (KING PHARMA)
  30 mcg = $24.99
  90 mcg = $53.97
• Unithroid 88 MCG TABS [Bottle] (LANNETT)
  30 mcg = $18.99
  60 mcg = $29.98
• Synthroid 88 MCG TABS [Bottle] (ABBOTT)
  30 mcg = $28.99
  90 mcg = $64.97
• Synthroid 137 MCG TABS [Bottle] (ABBOTT)
  30 mcg = $32.99
  90 mcg = $98.97
• Levothroid 200 MCG TABS [Bottle] (FOREST)
  30 mcg = $16.99
  90 mcg = $35.97
• Synthroid 50 MCG TABS [Bottle] (ABBOTT)
  30 mcg = $25.99
  90 mcg = $57.97
• Levothyroxine Sodium 25 MCG TABS [Bottle] (MYLAN)
  30 mcg = $13.99
  60 mcg = $19.98
• Levoxyl 112 MCG TABS [Bottle] (KING PHARMA)
  30 mcg = $23.99
  90 mcg = $49.97
• Levothroid 88 MCG TABS [Bottle] (FOREST)
  30 mcg = $14.99
  90 mcg = $25.97
• Synthroid 175 MCG TABS [Bottle] (ABBOTT)
  30 mcg = $35.99
  90 mcg = $84.97
• Levoxyl 137 MCG TABS [Bottle] (KING PHARMA)
  30 mcg = $26.99
  90 mcg = $57.97
• Tirosint 112 MCG CAPS [Box] (AKRIMAX PHARMACEUTICALS)
  28 mcg = $35.99
  84 mcg = $79.97
• Levoxyl 100 MCG TABS [Bottle] (KING PHARMA)
  30 mcg = $22.99
  90 mcg = $47.97
• Levothroid 175 MCG TABS [Bottle] (FOREST)
  30 mcg = $16.99
  90 mcg = $29.97
• Levothroid 150 MCG TABS [Bottle] (FOREST)
  30 mcg = $15.99
  60 mcg = $23.98
• Synthroid 25 MCG TABS [Bottle] (ABBOTT)
  30 mcg = $24.99
  90 mcg = $52.97
• Synthroid 75 MCG TABS [Bottle] (ABBOTT)
  30 mcg = $27.99
  90 mcg = $61.97
• Unithroid 150 MCG TABS [Bottle] (LANNETT)
  30 mcg = $20.99
  60 mcg = $30.97
• Tirosint 25 MCG CAPS [Box] (AKRIMAX PHARMACEUTICALS)
  28 mcg = $29.66
  56 mcg = $50.51
• Levoxyl 200 MCG TABS [Bottle] (KING PHARMA)
  30 mcg = $28.99
  90 mcg = $65.97
• Levothroid 75 MCG TABS [Bottle] (FOREST)
  30 mcg = $14.99
  60 mcg = $20.98
• Synthroid 300 MCG TABS [Bottle] (ABBOTT)
  30 mcg = $44.99
  90 mcg = $115.97
• Synthroid 125 MCG TABS [Bottle] (ABBOTT)
  30 mcg = $32.99
  90 mcg = $78.97
• Tirosint 13 MCG CAPS [Box] (AKRIMAX PHARMACEUTICALS)
  28 mcg = $31.99
  84 mcg = $73.97
• Levoxyl 175 MCG TABS [Bottle] (KING PHARMA)
  30 mcg = $28.99
  90 mcg = $64.97
• Levoxyl 150 MCG TABS [Bottle] (KING PHARMA)
  30 mcg = $22.99
  90 mcg = $49.97
• Levothroid 125 MCG TABS [Bottle] (FOREST)
  30 mcg = $15.99
  90 mcg = $29.97
• Synthroid 150 MCG TABS [Bottle] (ABBOTT)
  30 mcg = $33.99
  90 mcg = $75.97
• Levothroid 50 MCG TABS [Bottle] (FOREST)
  30 mcg = $14.99
  60 mcg = $19.97
• Unithroid 200 MCG TABS [Bottle] (LANNETT)
  30 mcg = $25.99
  60 mcg = $39.97
• Synthroid 112 MCG TABS [Bottle] (ABBOTT)
  30 mcg = $30.99
  90 mcg = $74.97
• Levothyroxine Sodium 300 MCG TABS [Bottle] (MYLAN)
  30 mcg = $20.99
  90 mcg = $42.97
• Levothroid 25 MCG TABS [Bottle] (FOREST)
  30 mcg = $14.99
  90 mcg = $21.97
• Synthroid 200 MCG TABS [Bottle] (ABBOTT)
  30 mcg = $35.99
  90 mcg = $84.97
• Levothroid 137 MCG TABS [Bottle] (FOREST)
  30 mcg = $14.99
  90 mcg = $28.97
• Levothroid 112 MCG TABS [Bottle] (FOREST)
  30 mcg = $15.99
  90 mcg = $25.97
• Unithroid 25 MCG TABS [Bottle] (LANNETT)
  30 mcg = $16.99
  60 mcg = $25.97
• Levothyroxine Sodium 112 MCG TABS [Bottle] (MYLAN)
  30 mcg = $15.99
  60 mcg = $25.98
• Unithroid 125 MCG TABS [Bottle] (LANNETT)
  30 mcg = $19.99
  90 mcg = $39.97
• Unithroid 50 MCG TABS [Bottle] (LANNETT)
  30 mcg = $17.99
  90 mcg = $31.97
• Tirosint 50 MCG CAPS [Box] (AKRIMAX PHARMACEUTICALS)
  28 mcg = $34.99
  84 mcg = $82.97

Warning: This pricing information is subject to change at the sole discretion of DS Pharmacy. For the most current and up-to-date pricing information, please visit drugstore.com.

• Levoxyl 0.025 MG Oral Tablet (Caremark L.L.C.)
• Levoxyl 0.025 MG Oral Tablet (King Pharmaceuticals, Inc.)
• Levoxyl 0.05 MG Oral Tablet (Caremark L.L.C.)
• Levoxyl 0.05 MG Oral Tablet (King Pharmaceuticals, Inc.)
• Levoxyl 0.075 MG Oral Tablet (Caremark L.L.C.)
• Levoxyl 0.075 MG Oral Tablet (King Pharmaceuticals, Inc.)
• Levoxyl 0.088 MG Oral Tablet (Caremark L.L.C.)
• Levoxyl 0.088 MG Oral Tablet (King Pharmaceuticals, Inc.)
• Levoxyl 0.1 MG Oral Tablet (Caremark L.L.C.)
• Levoxyl 0.1 MG Oral Tablet (King Pharmaceuticals, Inc.)
• Levoxyl 0.112 MG Oral Tablet (Caremark L.L.C.)
• Levoxyl 0.112 MG Oral Tablet (King Pharmaceuticals, Inc.)
• Levoxyl 0.125 MG Oral Tablet (Caremark L.L.C.)
• Levoxyl 0.125 MG Oral Tablet (King Pharmaceuticals, Inc.)
• Levoxyl 0.137 MG Oral Tablet (King Pharmaceuticals, Inc.)
• Levoxyl 0.15 MG Oral Tablet (Caremark L.L.C.)
• Levoxyl 0.15 MG Oral Tablet (King Pharmaceuticals, Inc.)
• Levoxyl 0.175 MG Oral Tablet (King Pharmaceuticals, Inc.)
• Levoxyl 0.2 MG Oral Tablet (King Pharmaceuticals, Inc.)
• Synthroid 0.025 MG Oral Tablet (Abbott Laboratories)
• Synthroid 0.025 MG Oral Tablet (Caremark L.L.C.)
• Synthroid 0.05 MG Oral Tablet (Abbott Laboratories)
• Synthroid 0.05 MG Oral Tablet (Caremark L.L.C.)
• Synthroid 0.088 MG Oral Tablet (Abbott Laboratories)
• Synthroid 0.088 MG Oral Tablet (Caremark L.L.C.)
• Synthroid 0.112 MG Oral Tablet (Abbott Laboratories)
• Synthroid 0.112 MG Oral Tablet (Caremark L.L.C.)
• Synthroid 0.125 MG Oral Tablet (Abbott Laboratories)
• Synthroid 0.125 MG Oral Tablet (Caremark L.L.C.)
• Synthroid 0.137 MG Oral Tablet (Abbott Laboratories)
• Synthroid 0.15 MG Oral Tablet (Abbott Laboratories)
• Synthroid 0.15 MG Oral Tablet (Caremark L.L.C.)
• Synthroid 0.175 MG Oral Tablet (Abbott Laboratories)
• Synthroid 0.175 MG Oral Tablet (Caremark L.L.C.)
• Synthroid 0.2 MG Oral Tablet (Abbott Laboratories)
• Synthroid 0.2 MG Oral Tablet (Caremark L.L.C.)
• Synthroid 0.3 MG Oral Tablet (Abbott Laboratories)
• Synthroid 100 MCG Oral Tablet (Abbott Laboratories)
• Synthroid 100 MCG Oral Tablet (Caremark L.L.C.)
• Synthroid 75 MCG Oral Tablet (Abbott Laboratories)
• Synthroid 75 MCG Oral Tablet (Caremark L.L.C.)
• Tirosint 0.013 7 Day Pack (Akrimax Pharmaceuticals, LLC)
• Tirosint 0.013 7 Day Pack (Institut Biochimique SA)
• Tirosint 0.025 7 Day Pack (Akrimax Pharmaceuticals, LLC)
• Tirosint 0.025 7 Day Pack (Institut Biochimique SA)
• Tirosint 0.05 7 Day Pack (Akrimax Pharmaceuticals, LLC)
• Tirosint 0.05 7 Day Pack (Institut Biochimique SA)
• Tirosint 0.075 7 Day Pack (Akrimax Pharmaceuticals, LLC)
• Tirosint 0.075 7 Day Pack (Institut Biochimique SA)
• Tirosint 100 MCG 7 Day Pack (Akrimax Pharmaceuticals, LLC)
• Tirosint 100 MCG 7 Day Pack (Institut Biochimique SA)
• Tirosint 112 MCG 7 Day Pack (Akrimax Pharmaceuticals, LLC)
• Tirosint 125 MCG 7 Day Pack (Akrimax Pharmaceuticals, LLC)
• Tirosint 125 MCG 7 Day Pack (Institut Biochimique SA)
• Tirosint 137 MCG 7 Day Pack (Akrimax Pharmaceuticals, LLC)
• Tirosint 150 MCG 7 Day Pack (Akrimax Pharmaceuticals, LLC)
• Tirosint 150 MCG 7 Day Pack (Institut Biochimique SA)
• Tirosint 88 MCG 7 Day Pack (Akrimax Pharmaceuticals, LLC)