Pediatric Formulary

Dosages

Side effects in children

Warnings & precautions in children

Contra-indications in children

Interactions

Renal impairment

References

Levothyroxine

Generic name

Levothyroxine

Brand name

ATC Code

H03AA01

Pharmacokinetics in children

The absorption after oral administration is variable and incomplete: 50-80%, particularly in the presence of food. The intravenous dose is therefore lower.

A second drug has not been selected yet.
Press ‘drugs’ followed with and select second drug from list to add the second drug to the comparison.

dose recommendation of formulary compared to licensed use (on-label versus off-label)

No information is present at this moment.

A second drug has not been selected yet.
Press ‘drugs’ followed with and select second drug from list to add the second drug to the comparison.

Available formulations

No information is present at this moment.

A second drug has not been selected yet.
Press ‘drugs’ followed with and select second drug from list to add the second drug to the comparison.

Dosages

Hypothyroidism
Oral 0 months up to 6 months 6 - 10 microg./kg/day in 1 dose Directions for administration: Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day. The dose should then be titrated based on the TSH level (aiming for low normal) and FT4 level (aiming for high normal) If the hypothyroidism lasts longer, the starting dose should be lower than the desired maintenance dose (50%) in order to avoid side effects 6 months up to 1 year 5 - 8 microg./kg/day in 1 dose Directions for administration: Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day. The dose should then be titrated based on the TSH level (aiming for low normal) and FT4 level (aiming for high normal) If the hypothyroidism lasts longer, the starting dose should be lower than the desired maintenance dose (50%) in order to avoid side effects 1 year up to 5 years 4 - 6 microg./kg/day in 1 dose Directions for administration: Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day. The dose should then be titrated based on the TSH level (aiming for low normal) and FT4 level (aiming for high normal) If the hypothyroidism lasts longer, the starting dose should be lower than the desired maintenance dose (50%) in order to avoid side effects 5 years up to 12 years 3 - 5 microg./kg/day in 1 dose Directions for administration: Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day. The dose should then be titrated based on the TSH level (aiming for low normal) and FT4 level (aiming for high normal) If the hypothyroidism lasts longer, the starting dose should be lower than the desired maintenance dose (50%) in order to avoid side effects 12 years up to 18 years 2 - 3 microg./kg/day in 1 dose Directions for administration: Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day. The dose should then be titrated based on the TSH level (aiming for low normal) and FT4 level (aiming for high normal) If the hypothyroidism lasts longer, the starting dose should be lower than the desired maintenance dose (50%) in order to avoid side effects Intravenous 1 month up to 18 years If not absorbed orally. The IV dose is derived from the oral dose in consultation with a paediatrician-endocrinologist. The intravenous dose is lower than the oral dose, due to the varying and incomplete absorption after oral administration.

Hypothyroidism

Oral
- 0 months up to 6 months
  - 6 - 10 microg./kg/day in 1 dose
  - Directions for administration:
    Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day.
  - The dose should then be titrated based on the TSH level (aiming for low normal) and FT4 level (aiming for high normal)
    If the hypothyroidism lasts longer, the starting dose should be lower than the desired maintenance dose (50%) in order to avoid side effects
- 6 months up to 1 year
  - 5 - 8 microg./kg/day in 1 dose
  - Directions for administration:
    Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day.
  - The dose should then be titrated based on the TSH level (aiming for low normal) and FT4 level (aiming for high normal)
    If the hypothyroidism lasts longer, the starting dose should be lower than the desired maintenance dose (50%) in order to avoid side effects
- 1 year up to 5 years
  - 4 - 6 microg./kg/day in 1 dose
  - Directions for administration:
    Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day.
  - The dose should then be titrated based on the TSH level (aiming for low normal) and FT4 level (aiming for high normal)
    If the hypothyroidism lasts longer, the starting dose should be lower than the desired maintenance dose (50%) in order to avoid side effects
- 5 years up to 12 years
  - 3 - 5 microg./kg/day in 1 dose
  - Directions for administration:
    Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day.
  - The dose should then be titrated based on the TSH level (aiming for low normal) and FT4 level (aiming for high normal)
    If the hypothyroidism lasts longer, the starting dose should be lower than the desired maintenance dose (50%) in order to avoid side effects
- 12 years up to 18 years
  - 2 - 3 microg./kg/day in 1 dose
  - Directions for administration:
    Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day.
  - The dose should then be titrated based on the TSH level (aiming for low normal) and FT4 level (aiming for high normal)
    If the hypothyroidism lasts longer, the starting dose should be lower than the desired maintenance dose (50%) in order to avoid side effects
Intravenous
- 1 month up to 18 years
  - If not absorbed orally. The IV dose is derived from the oral dose in consultation with a paediatrician-endocrinologist.
    The intravenous dose is lower than the oral dose, due to the varying and incomplete absorption after oral administration.

Congenital hypothyroidism
Oral 0 years up to 1 year Initial dose: 10 microg./kg/day in 1 dose Induction phase in order to achieve normalization of FT4 and TSH. In severe hypothyroidism (FT4 < 8 pmol/l), the initial dose is repeated after 12 hours as a one-off.. Maintenance dose: 5 - 8 microg./kg/day in 1 dose Directions for administration: Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day. The dose adjustment is about 1 mcg/kg/day, rounded off to the nearest unit of ± 6.25 mcg (a quarter of a tablet of 25 mcg). The dosage should then be titrated based on the TSH and FT4 values. Target values: Induction phase: FT4 25-35 pmol/l; TSH 0.4-4.0 Maintenance: FT4: in the reference range, TSH 0.4-4.0 1 year up to 5 years Initial dose: 10 microg./kg/day in 1 dose Induction phase in order to achieve normalization of FT4 and TSH. In severe hypothyroidism (FT4 < 8 pmol/l), the initial dose is repeated after 12 hours as a one-off.. Maintenance dose: 5 - 6 microg./kg/day in 1 dose Directions for administration: Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day The dose adjustment is about 1 mcg/kg/day, rounded off to the nearest unit of ± 6.25 mcg (a quarter of a tablet of 25 mcg). The dosage should then be titrated based on the TSH and FT4 values. Target values: Induction phase: FT4 25-35 pmol/l; TSH 0.4-4.0 Maintenance: FT4: in the reference range, TSH 0.4-4.0 5 years up to 12 years Initial dose: 10 microg./kg/day in 1 dose Induction phase in order to achieve normalization of FT4 and TSH. In severe hypothyroidism (FT4 < 8 pmol/l), the initial dose is repeated after 12 hours as a one-off.. Maintenance dose: 3 - 5 microg./kg/day in 1 dose Directions for administration: Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day The dose adjustment is about 1 mcg/kg/day, rounded off to the nearest unit of ± 6.25 mcg (a quarter of a tablet of 25 mcg). The dosage should then be titrated based on the TSH and FT4 values. Target values: Induction phase: FT4 25-35 pmol/l; TSH 0.4-4.0 Maintenance: FT4: in the reference range, TSH 0.4-4.0 12 years up to 18 years Initial dose: 10 microg./kg/day in 1 dose Induction phase in order to achieve normalization of FT4 and TSH. In severe hypothyroidism (FT4 < 8 pmol/l), the initial dose is repeated after 12 hours as a one-off.. Maintenance dose: 2 - 4 microg./kg/day in 1 dose Directions for administration: Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day. The dose adjustment is about 1 mcg/kg/day, rounded off to the nearest unit of ± 6.25 mcg (a quarter of a tablet of 25 mcg). The dosage should then be titrated based on the TSH and FT4 values. Target values: Induction phase: FT4 25-35 pmol/l; TSH 0.4-4.0 Maintenance: FT4: in the reference range, TSH 0.4-4.0

Congenital hypothyroidism

Oral
- 0 years up to 1 year
  - Initial dose: 10 microg./kg/day in 1 dose Induction phase in order to achieve normalization of FT4 and TSH. In severe hypothyroidism (FT4 < 8 pmol/l), the initial dose is repeated after 12 hours as a one-off..
  - Maintenance dose: 5 - 8 microg./kg/day in 1 dose
  - Directions for administration:
    Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day.
  - The dose adjustment is about 1 mcg/kg/day, rounded off to the nearest unit of ± 6.25 mcg (a quarter of a tablet of 25 mcg).
    The dosage should then be titrated based on the TSH and FT4 values.
    
    Target values:
    Induction phase: FT4 25-35 pmol/l; TSH 0.4-4.0
    Maintenance: FT4: in the reference range, TSH 0.4-4.0
- 1 year up to 5 years
  - Initial dose: 10 microg./kg/day in 1 dose Induction phase in order to achieve normalization of FT4 and TSH. In severe hypothyroidism (FT4 < 8 pmol/l), the initial dose is repeated after 12 hours as a one-off..
  - Maintenance dose: 5 - 6 microg./kg/day in 1 dose
  - Directions for administration:
    Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day
  - The dose adjustment is about 1 mcg/kg/day, rounded off to the nearest unit of ± 6.25 mcg (a quarter of a tablet of 25 mcg).
    The dosage should then be titrated based on the TSH and FT4 values.
    
    Target values:
    Induction phase: FT4 25-35 pmol/l; TSH 0.4-4.0
    Maintenance: FT4: in the reference range, TSH 0.4-4.0
- 5 years up to 12 years
  - Initial dose: 10 microg./kg/day in 1 dose Induction phase in order to achieve normalization of FT4 and TSH. In severe hypothyroidism (FT4 < 8 pmol/l), the initial dose is repeated after 12 hours as a one-off..
  - Maintenance dose: 3 - 5 microg./kg/day in 1 dose
  - Directions for administration:
    Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day
  - The dose adjustment is about 1 mcg/kg/day, rounded off to the nearest unit of ± 6.25 mcg (a quarter of a tablet of 25 mcg).
    The dosage should then be titrated based on the TSH and FT4 values.
    
    Target values:
    Induction phase: FT4 25-35 pmol/l; TSH 0.4-4.0
    Maintenance: FT4: in the reference range, TSH 0.4-4.0
- 12 years up to 18 years
  - Initial dose: 10 microg./kg/day in 1 dose Induction phase in order to achieve normalization of FT4 and TSH. In severe hypothyroidism (FT4 < 8 pmol/l), the initial dose is repeated after 12 hours as a one-off..
  - Maintenance dose: 2 - 4 microg./kg/day in 1 dose
  - Directions for administration:
    Levothyroxine can be taken in the morning or evening with or without food, but should be taken the same way every day.
  - The dose adjustment is about 1 mcg/kg/day, rounded off to the nearest unit of ± 6.25 mcg (a quarter of a tablet of 25 mcg).
    The dosage should then be titrated based on the TSH and FT4 values.
    
    Target values:
    Induction phase: FT4 25-35 pmol/l; TSH 0.4-4.0
    Maintenance: FT4: in the reference range, TSH 0.4-4.0

Supplementation after thyrostatic drugs
Oral 1 year up to 5 years 25 microg./day in 1 dose If the TSH is > 4 mU/litre, increase the levothyroxine. 5 years up to 12 years 50 microg./day in 1 dose If the TSH is > 4 mU/litre, increase the levothyroxine. 12 years up to 18 years 75 microg./day in 1 dose If the TSH is > 4 mU/litre, increase the levothyroxine.

Juvenile myxoedema
Oral ≥ 1 year ^[3] Initial dose: 2.5 - 5 microg./kg/day in 1 dose Maintenance dose: increase the starting dose (total daily dose) every 2-4 weeks by 50 mcg to the highest dose that gives no side effects..

A second drug has not been selected yet.
Press ‘drugs’ followed with and select second drug from list to add the second drug to the comparison.

Renal impaiment in children > 3 months

GFR ≥10 ml/min/1.73m2: Dose adjustment not required.

GFR <10 ml/min/1.73m2: A general recommendation on dose adjustment cannot be provided.

A second drug has not been selected yet.
Press ‘drugs’ followed with and select second drug from list to add the second drug to the comparison.

The complete list of all undesirable drug reactions can be found in the national Summary of Product Characteristics (SmPC) – click here

Side effects in children

In very rare cases (0.01-0.1%), a pseudotumor cerebri may occur, particularly in children [SmPC Eferox].
There have been reported cases of circulatory collapse in low birth weight premature infants [SmPC L-Thyroxin Henning]. In children, prolonged use of excessively high T4 doses can lead to disorders of bone maturation.

A second drug has not been selected yet.
Press ‘drugs’ followed with and select second drug from list to add the second drug to the comparison.

The complete list of all contra-indications can be found in the national Summary of Product Characteristics (SmPC) – click here

Contra-indications

No information available on specific contra indications in children.

The complete list of all warnings and precautions can be found in the national Summary of Product Characteristics (SmPC) – click here

Warnings & precautions in children

Signs of overdose: Nervousness, sleeplessness, tremor, tachycardia, sweating, vomiting, fever, weight loss and pseudotumor cerebri.
Locust bean gum (Nutriton) and soya bind thyroid hormone and should not be taken at the same time as it.

In children, attention should be paid to any epiphysiolysis of the femoral head. Haemodynamic parameters should be monitored when levothyroxine treatment is initiated in premature infants with low birth weight, as poor adrenal function may lead to circulatory collapse.

A second drug has not been selected yet.
Press ‘drugs’ followed with and select second drug from list to add the second drug to the comparison.

Interactions

The complete list of all interactions can be found in the national Summary of Product Characteristics (SmPC) – click here

A second drug has not been selected yet.
Press ‘drugs’ followed with and select second drug from list to add the second drug to the comparison.

References

Rademaker C.M.A. et al, Geneesmiddelen-Formularium voor Kinderen, 2007
Noordam C et al, Werkboek Kinderendocrinologie, digitale publicatie op www.nvk.nl (alleen leden), 2010
Aspen Pharma Trading Limited, SmPC Eltroxin (RVG 08451) 24-03-2017, www.geneesmiddeleninformatiebank.nl
UpToDate, Levothyroxine: Drug Information, Version 208.0
ABDA, Wirkstoffdossier: Euthyrox 100 Mikrogramm, 04/2018
Aktories et al., Allgemeine und spezielle Pharmakologie und Toxikologie, 9. Auflage, 2005
MMI, Gelbe Liste, 16/03/2018
Gemeinsamer Bundesausschuss, Anlage VII zum Abschnitt M der Arzneimittel-Richtlinie, Accessed April 12, 2018
Sanofi-Aventis, SmPC L-Thyroxin Henning® inject (48613.00.00), 09/2017
Sanofi-Aventis, SmPC L-Thyroxin Henning® Tropfen (49804.00.00), 09/2017
Aristo Pharma, SmPC Eferox® 175/200, Tabletten (53051.03.00, 51838.02.00), 10/2015
Aristo Pharma, SmPC Eferox® Lösung zum Einnehmen (88487.00.00), 11/2017
Sanofi-Aventis Deutschland GmbH, SmPC L-Thyroxin Henning® 25/50/75/100/125/150/175/200 Tabletten (1451.00.00), 06/2023
Merck Serono, SmPC Euthyrox® 25/50/75/88/100/112/125/137/150/175/200 Mikrogramm Tabletten, 10/2017
Aristo Pharma GmbH, SmPC Eferox® 25/50/85/100/125/150 Mikrogramm, Tabletten (5189.00.00), 01/2023
Mersebach, H., Intestinal adsorption of levothyroxine by antacids and laxatives: case stories and in vitro experiments, Pharmacol. Toxicol., 1999, 84, 107-109
Leger et al, European Society for Paediatric Endocrinology Consensus Guidelines on Screening, Diagnosis, and Management of Congenital Hypothyroidism, J Clin Endocrinol Metab, 2014, 99(2), 363-84

A second drug has not been selected yet.
Press ‘drugs’ followed with and select second drug from list to add the second drug to the comparison.

Levothyroxine

Levothyroxine

Pharmacokinetics in children

dose recommendation of formulary compared to licensed use (on-label versus off-label)

Available formulations

Dosages

Renal impaiment in children > 3 months

Side effects in children

Contra-indications

Warnings & precautions in children

Interactions

References

Changes

Changes