2 DOSAGE AND ADMINISTRATION Administer once daily, preferably on an empty stomach, one-half to one hour before breakfast with a full glass of water. 1) Administer at least 4 hours before or after drugs that are known to interfere with absorption.
1) Evaluate the need for dose adjustments when regularly administering within one hour of certain foods that may affect absorption. 1) Advise patients to stop biotin and biotin-containing supplements at least 2 days before assessing TSH and/or T4 levels.
2) Starting dose depends on a variety of factors, including age, body weight, cardiovascular status, and concomitant medications. Peak therapeutic effect may not be attained for 4 to 6 weeks. 2) See full prescribing information for dosing in specific patient populations.
3) Adequacy of therapy determined with periodic monitoring of TSH and/or T4 as well as clinical status. 1 Important Administration Instructions Administer levothyroxine sodium tablets as a single daily dose, on an empty stomach, one-half to one hour before breakfast with a full glass of water to avoid choking or gagging [see Adverse Reactions (6) ].
1) ]. 3) ]. Administer levothyroxine sodium tablets to pediatric patients who cannot swallow intact tablets by crushing the tablet, suspending the freshly crushed tablet in a small amount (5 to 10 mL) of water and immediately administering the suspension by spoon or dropper.
Ensure the patient ingests the full amount of the suspension. Do not store the suspension. 9) ]. 3) , Warnings and Precautions (5) , and Drug Interactions (7) ] . 4) ]. 3) ]. For secondary or tertiary hypothyroidism, serum TSH is not a reliable measure of levothyroxine sodium dosage adequacy and should not be used to monitor therapy.
3) ]. Inquire whether patients are taking biotin or biotin-containing supplements. 10) ]. The peak therapeutic effect of a given dose of levothyroxine sodium tablets may not be attained for 4 to 6 weeks. 3 Recommended Dosage and Titration Primary, Secondary, and Tertiary Hypothyroidism in Adults The recommended starting daily dosage of levothyroxine sodium tablets in adults with primary, secondary, or tertiary hypothyroidism is based on age and comorbid cardiac conditions, as described in Table 1.
For patients at risk of atrial fibrillation or patients with underlying cardiac disease, start with a lower dosage and titrate the dosage more slowly to avoid exacerbation of cardiac symptoms. 2) ]. Table 1. Levothyroxine Sodium Tablets Dosing Guidelines for Hypothyroidism in Adults* *Dosages greater than 200 mcg/day are seldom required.
1) and Drug Interactions (7) ]. 6 mcg/kg/day. Some patients require a lower starting dose. 5 to 25 mcg increments every 4 to 6 weeks, as needed until the patient is euthyroid. 6 mcg/kg/day) Titrate dosage every 6 to 8 weeks, as needed until the patient is euthyroid.
6 mcg/kg/day) Primary, Secondary, and Tertiary Hypothyroidism in Pediatric Patients The recommended starting daily dosage of levothyroxine sodium tablets in pediatric patients with primary, secondary, or tertiary hypothyroidism is based on body weight and changes with age as described in Table 2.
2) ]. Table 2. 4) ] . Pediatric Patients from Birth to 3 Months of Age at Risk for Cardiac Failure Start at a lower starting dosage and increase the dosage every 4 to 6 weeks as needed based on clinical and laboratory response. Pediatric Patients at Risk for Hyperactivity To minimize the risk of hyperactivity, start at one-fourth the recommended full replacement dosage, and increase on a weekly basis by one-fourth the full recommended replacement dosage until the full recommended replacement dosage is reached.
Hypothyroidism in Pregnant Patients For pregnant patients with pre-existing hypothyroidism, measure serum TSH and free-T4 as soon as pregnancy is confirmed and, at minimum, during each trimester of pregnancy. In pregnant patients with primary hypothyroidism, maintain serum TSH in the trimester-specific reference range.
The recommended daily dosage of levothyroxine sodium tablets in pregnant patients is described in Table 3. Table 3. 5 to 25 mcg per day. Monitor TSH every 4 weeks until a stable dose is reached and serum TSH is within normal trimester-specific range.
Reduce levothyroxine sodium dosage to pre-pregnancy levels immediately after delivery. Monitor serum TSH 4 to 8 weeks postpartum. 6 mcg/kg/day Monitor serum TSH every 4 weeks and adjust levothyroxine sodium dosage until serum TSH is within normal trimester-specific range.
0 mcg/kg/day TSH Suppression in Well-differentiated Thyroid Cancer in Adult and Pediatric Patients The levothyroxine sodium dosage is based on the target level of TSH suppression for the stage and clinical status of thyroid cancer.
4 Monitoring TSH and/or Thyroxine (T4) Levels Assess the adequacy of therapy by periodic assessment of laboratory tests and clinical evaluation. Biotin supplementation may interfere with immunoassays for TSH, T4, and T3, resulting in erroneous thyroid hormone test results.
10) ] . Persistent clinical and laboratory evidence of hypothyroidism despite an apparent adequate replacement dose of levothyroxine sodium may be evidence of inadequate absorption, poor compliance, drug interactions, or a combination of these factors.
Adults In adult patients with primary hypothyroidism, monitor serum TSH levels after an interval of 6 to 8 weeks after any change in dosage. In patients on a stable and appropriate replacement dosage, evaluate clinical and biochemical response every 6 to 12 months and whenever there is a change in the patient’s clinical status.
Pediatric Patients In patients with hypothyroidism, assess the adequacy of replacement therapy by measuring both serum TSH and total or free-T4. Monitor TSH and total or free-T4 in pediatric patients as follows: 2 and 4 weeks after the initiation of treatment, 2 weeks after any change in dosage, and then every 3 to 12 months thereafter following dosage stabilization until growth is completed.
Poor compliance or abnormal values may necessitate more frequent monitoring. Perform routine clinical examination, including assessment of development, mental and physical growth, and bone maturation, at regular intervals. The general aim of therapy is to normalize the serum TSH level.
TSH may not normalize in some patients due to in utero hypothyroidism causing a resetting of pituitary-thyroid feedback. Failure of the serum T4 to increase into the upper half of the normal range within 2 weeks of initiation of levothyroxine sodium therapy and/or of the serum TSH to decrease below 20 mIU per litre within 4 weeks may indicate the patient is not receiving adequate therapy.
4) ] . Secondary and Tertiary Hypothyroidism Monitor serum free-T4 levels and maintain in the upper half of the normal range in these patients. 1 Important Administration Instructions Administer levothyroxine sodium tablets as a single daily dose, on an empty stomach, one-half to one hour before breakfast with a full glass of water to avoid choking or gagging [see Adverse Reactions (6) ].
1) ]. 3) ]. Administer levothyroxine sodium tablets to pediatric patients who cannot swallow intact tablets by crushing the tablet, suspending the freshly crushed tablet in a small amount (5 to 10 mL) of water and immediately administering the suspension by spoon or dropper.
Ensure the patient ingests the full amount of the suspension. Do not store the suspension. 9) ]. 3) , Warnings and Precautions (5) , and Drug Interactions (7) ] . 4) ]. 3) ]. For secondary or tertiary hypothyroidism, serum TSH is not a reliable measure of levothyroxine sodium dosage adequacy and should not be used to monitor therapy.
3) ]. Inquire whether patients are taking biotin or biotin-containing supplements. 10) ]. The peak therapeutic effect of a given dose of levothyroxine sodium tablets may not be attained for 4 to 6 weeks. 3 Recommended Dosage and Titration Primary, Secondary, and Tertiary Hypothyroidism in Adults The recommended starting daily dosage of levothyroxine sodium tablets in adults with primary, secondary, or tertiary hypothyroidism is based on age and comorbid cardiac conditions, as described in Table 1.
For patients at risk of atrial fibrillation or patients with underlying cardiac disease, start with a lower dosage and titrate the dosage more slowly to avoid exacerbation of cardiac symptoms. 2) ]. Table 1. Levothyroxine Sodium Tablets Dosing Guidelines for Hypothyroidism in Adults* *Dosages greater than 200 mcg/day are seldom required.
1) and Drug Interactions (7) ]. 6 mcg/kg/day. Some patients require a lower starting dose. 5 to 25 mcg increments every 4 to 6 weeks, as needed until the patient is euthyroid. 6 mcg/kg/day) Titrate dosage every 6 to 8 weeks, as needed until the patient is euthyroid.
6 mcg/kg/day) Primary, Secondary, and Tertiary Hypothyroidism in Pediatric Patients The recommended starting daily dosage of levothyroxine sodium tablets in pediatric patients with primary, secondary, or tertiary hypothyroidism is based on body weight and changes with age as described in Table 2.
2) ]. Table 2. 4) ] . Pediatric Patients from Birth to 3 Months of Age at Risk for Cardiac Failure Start at a lower starting dosage and increase the dosage every 4 to 6 weeks as needed based on clinical and laboratory response. Pediatric Patients at Risk for Hyperactivity To minimize the risk of hyperactivity, start at one-fourth the recommended full replacement dosage, and increase on a weekly basis by one-fourth the full recommended replacement dosage until the full recommended replacement dosage is reached.
Hypothyroidism in Pregnant Patients For pregnant patients with pre-existing hypothyroidism, measure serum TSH and free-T4 as soon as pregnancy is confirmed and, at minimum, during each trimester of pregnancy. In pregnant patients with primary hypothyroidism, maintain serum TSH in the trimester-specific reference range.
The recommended daily dosage of levothyroxine sodium tablets in pregnant patients is described in Table 3. Table 3. 5 to 25 mcg per day. Monitor TSH every 4 weeks until a stable dose is reached and serum TSH is within normal trimester-specific range.
Reduce levothyroxine sodium dosage to pre-pregnancy levels immediately after delivery. Monitor serum TSH 4 to 8 weeks postpartum. 6 mcg/kg/day Monitor serum TSH every 4 weeks and adjust levothyroxine sodium dosage until serum TSH is within normal trimester-specific range.
0 mcg/kg/day TSH Suppression in Well-differentiated Thyroid Cancer in Adult and Pediatric Patients The levothyroxine sodium dosage is based on the target level of TSH suppression for the stage and clinical status of thyroid cancer.
Primary, Secondary, and Tertiary Hypothyroidism in Adults The recommended starting daily dosage of levothyroxine sodium tablets in adults with primary, secondary, or tertiary hypothyroidism is based on age and comorbid cardiac conditions, as described in Table 1.
For patients at risk of atrial fibrillation or patients with underlying cardiac disease, start with a lower dosage and titrate the dosage more slowly to avoid exacerbation of cardiac symptoms. 2) ]. Table 1. Levothyroxine Sodium Tablets Dosing Guidelines for Hypothyroidism in Adults* *Dosages greater than 200 mcg/day are seldom required.
1) and Drug Interactions (7) ]. 6 mcg/kg/day. Some patients require a lower starting dose. 5 to 25 mcg increments every 4 to 6 weeks, as needed until the patient is euthyroid. 6 mcg/kg/day) Titrate dosage every 6 to 8 weeks, as needed until the patient is euthyroid.
6 mcg/kg/day) Primary, Secondary, and Tertiary Hypothyroidism in Pediatric Patients The recommended starting daily dosage of levothyroxine sodium tablets in pediatric patients with primary, secondary, or tertiary hypothyroidism is based on body weight and changes with age as described in Table 2.
2) ]. Table 2. 4) ] . Pediatric Patients from Birth to 3 Months of Age at Risk for Cardiac Failure Start at a lower starting dosage and increase the dosage every 4 to 6 weeks as needed based on clinical and laboratory response. Pediatric Patients at Risk for Hyperactivity To minimize the risk of hyperactivity, start at one-fourth the recommended full replacement dosage, and increase on a weekly basis by one-fourth the full recommended replacement dosage until the full recommended replacement dosage is reached.
Hypothyroidism in Pregnant Patients For pregnant patients with pre-existing hypothyroidism, measure serum TSH and free-T4 as soon as pregnancy is confirmed and, at minimum, during each trimester of pregnancy. In pregnant patients with primary hypothyroidism, maintain serum TSH in the trimester-specific reference range.
The recommended daily dosage of levothyroxine sodium tablets in pregnant patients is described in Table 3. Table 3. 5 to 25 mcg per day. Monitor TSH every 4 weeks until a stable dose is reached and serum TSH is within normal trimester-specific range.
Reduce levothyroxine sodium dosage to pre-pregnancy levels immediately after delivery. Monitor serum TSH 4 to 8 weeks postpartum. 6 mcg/kg/day Monitor serum TSH every 4 weeks and adjust levothyroxine sodium dosage until serum TSH is within normal trimester-specific range.
0 mcg/kg/day TSH Suppression in Well-differentiated Thyroid Cancer in Adult and Pediatric Patients The levothyroxine sodium dosage is based on the target level of TSH suppression for the stage and clinical status of thyroid cancer.
4 Monitoring TSH and/or Thyroxine (T4) Levels Assess the adequacy of therapy by periodic assessment of laboratory tests and clinical evaluation. Biotin supplementation may interfere with immunoassays for TSH, T4, and T3, resulting in erroneous thyroid hormone test results.
10) ] . Persistent clinical and laboratory evidence of hypothyroidism despite an apparent adequate replacement dose of levothyroxine sodium may be evidence of inadequate absorption, poor compliance, drug interactions, or a combination of these factors.
Adults In adult patients with primary hypothyroidism, monitor serum TSH levels after an interval of 6 to 8 weeks after any change in dosage. In patients on a stable and appropriate replacement dosage, evaluate clinical and biochemical response every 6 to 12 months and whenever there is a change in the patient’s clinical status.
Pediatric Patients In patients with hypothyroidism, assess the adequacy of replacement therapy by measuring both serum TSH and total or free-T4. Monitor TSH and total or free-T4 in pediatric patients as follows: 2 and 4 weeks after the initiation of treatment, 2 weeks after any change in dosage, and then every 3 to 12 months thereafter following dosage stabilization until growth is completed.
Poor compliance or abnormal values may necessitate more frequent monitoring. Perform routine clinical examination, including assessment of development, mental and physical growth, and bone maturation, at regular intervals. The general aim of therapy is to normalize the serum TSH level.
TSH may not normalize in some patients due to in utero hypothyroidism causing a resetting of pituitary-thyroid feedback. Failure of the serum T4 to increase into the upper half of the normal range within 2 weeks of initiation of levothyroxine sodium therapy and/or of the serum TSH to decrease below 20 mIU per litre within 4 weeks may indicate the patient is not receiving adequate therapy.
4) ] . Secondary and Tertiary Hypothyroidism Monitor serum free-T4 levels and maintain in the upper half of the normal range in these patients. Adults In adult patients with primary hypothyroidism, monitor serum TSH levels after an interval of 6 to 8 weeks after any change in dosage.
In patients on a stable and appropriate replacement dosage, evaluate clinical and biochemical response every 6 to 12 months and whenever there is a change in the patient’s clinical status. Pediatric Patients In patients with hypothyroidism, assess the adequacy of replacement therapy by measuring both serum TSH and total or free-T4.
Monitor TSH and total or free-T4 in pediatric patients as follows: 2 and 4 weeks after the initiation of treatment, 2 weeks after any change in dosage, and then every 3 to 12 months thereafter following dosage stabilization until growth is completed.
Poor compliance or abnormal values may necessitate more frequent monitoring. Perform routine clinical examination, including assessment of development, mental and physical growth, and bone maturation, at regular intervals. The general aim of therapy is to normalize the serum TSH level.
TSH may not normalize in some patients due to in utero hypothyroidism causing a resetting of pituitary-thyroid feedback. Failure of the serum T4 to increase into the upper half of the normal range within 2 weeks of initiation of levothyroxine sodium therapy and/or of the serum TSH to decrease below 20 mIU per litre within 4 weeks may indicate the patient is not receiving adequate therapy.
4) ] . Secondary and Tertiary Hypothyroidism Monitor serum free-T4 levels and maintain in the upper half of the normal range in these patients.