See Supplemental Patient Information
- Larger doses of levothroxine alone or in combination with other drugs cause serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects [U.S. Black Box Warning]
- Doses within the range of daily hormonal requirements are ineffective for weight reduction in euthyroid patients
- Use cautiously in cardiovascular diseases. Start with low initial dosage increased slowly by small increments
- Cardiac symptoms may develop with over treatment
- In patients with diabetes mellitus, adrenal insufficiency (Addison’s disease), hypopituitarism and diabetes insipidus, it aggravates the intensity of previously obscured symptoms and requires appropriate adjustment of therapeutic measures directed at these concomitant disorders
- Levothyroxine potentiates the effects of anticoagulants; frequently monitor prothrombin time
- Overdosage causes thyrotoxicosis
- Monitor closely to the patient following the administration of the drug; adjust repeated dosage appropriately
- Monitor for signs and symptoms of cardiac overload in infants
Cautions: Use cautiously in
- Cardiovascular disease
- Seizures
- Diabetes mellitus
- Diabetes insipidus
- Addison's disease
- Geriatric patients (use lower initial dose)
Supplemental Patient Information
- Advise patients not to take levothyroxine for weight control
Pregnancy Category:A
Breastfeeding: Limited data on exogenous levothyroxine administration indicate no adverse effects on breastfed infant. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 27 November 2010). This drug is compatible and considered safe with breastfeeding based upon data from AAP Policy Guidelines (available at http://aappolicy.aappublications.org/cgi/content/full/pediatrics;108/3/776/T6 )
