Disclaimer to the Online Edition
This Manual has been designed for use in the NICU at London Health Sciences Centre (LHSC), London, Ontario, Canada, and represents clinical practice at this institution. The information contained within the Manual may not be applicable to other centres. If users of this Manual are not familiar with a drug, it is recommended that the official monograph be consulted before it is prescribed and administered. Any user of this information is advised that the contributors, Editor and LHSC are not responsible for any errors or omissions, and / or any consequences arising from the use of the information in this Manual.
levothyroxine
Indication
- Replacement therapy for hypothyroidism
Dosage Guidelines
- 10-15 mcg/kg ORAL/IV daily
Administration
- ORAL
- IV direct over 3-5 minutes
Adverse Effects
- Adverse effects result primarily those of hyperthyroidism due to therapeutic overdosage
- Signs of thyroid toxicity include tachycardia, palpitations and flushing
Comments
- The half-life of levothyroxine is over 1 week. It takes 4 to 6 weeks before steady state is reached.
- Dosage adjustments should be monitored at 3 to 6 week intervals
- Monitor TSH, free T3, free T4
- IV dosing is 75-80% of oral dose
- Separate administration from calcium, iron and multivitamins
Supplied As
- 150 mcg tablet to be dissolved in water to provide a 10 mcg/mL oral solution
- 100 mcg/mL IV syringe prepared by Pharmacy
References
LexiComp Sick Kids, LexiComp Pediatric and Neonatal, Neofax