Adult Dosing
Mild Hypothyroidism
- Initial: 25 mcg/day PO; may increase up to 25 mcg PO q1-2 wks; increase 5 mcg/day q1-2 wk in elderly patients
- Maintenance: 25-75 mcg/day PO
Myxedema
- Initial: 5 mcg/day PO; may increase up to 5-10 mcg/day q1-2 wks; increase 5 mcg/day q1-2 wk in elderly patients; once 25 mcg/day PO is reached, then increase by 5-25 mcg q1-2 wks until a satisfactory therapeutic response is attained
- Maintenance: 50-100 mcg/day
Simple (non-toxic) Goiter
- Initial: 5 mcg/day PO; may increase up to 5-10 mcg/day q1-2 wks; once 25 mcg/day PO is reached, increase by 12.5-25 mcg/day q1-2 wks; increase 5 mcg/day q1-2 wk in elderly patients
Thyroid suppression test
- 75-100 mcg/day PO x7 days; determine radioactive iodine uptake pre and post treatment; 50% or greater suppression of uptake indicates a normal thyroid-pituitary axis
Pediatric Dosing
Congenital Hypothyroidism
Infants
- Initial: 5 mcg/day PO, with 5 mcg increment q3-4 days until the desired response is achieved
- Maintenance: 20 mcg/day PO
Child 1-3 yrs
- Initial: 5 mcg/day PO, with 5 mcg increment q3-4 days until the desired response is achieved
- Maintenance: 50 mcg/day PO
Child >3 yrs
- Initial: 25 mcg/day PO; may increase up to 25 mcg PO q1-2 wks
- Maintenance: 25-75 mcg/day PO
[Outline]
- Thyroid hormones either alone or with other therapeutic agents should be avoided for the treatment of obesity or for weight loss in euthyroid patients. 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
- Use with great caution in cardiovascular system disorder, particularly the coronary arteries, patients with angina pectoris or the elderly or therapy should be initiated with low doses in such patients
- Starting dose of the therapy should not be increased by more than 5 mcg increments at 2-week intervals
- Prior to starting the therapy morphologic hypogonadism and nephrosis should be ruled out; if hypopituitarism is present, correct it first
- Initiate therapy at a very low dosage and increase gradually in myxedematous patients as they are very sensitive to thyroid
- A decreased level of adrenocortical activity commensurate with the lowered metabolic state may occur due to severe and prolonged hypothyroidism leading to precipitation of adrenocortical insufficiency. Therefore supplemental adrenocortical steroids may be necessary in severe and prolonged hypothyroidism
- Carefully monitor for a hyperthyroid state or aggravation of existing hyperthyroidism during the therapy
- Therapy may aggravate the intensity of symptoms in patients with concomitant diabetes mellitus or insipidus or adrenal cortical insufficiency
- In myxedema coma therapy requires simultaneous administration of glucocorticoids
- Closely monitor prothombin time in thyroid-treated patients on oral anticoagulants and adjust dosage on the basis of frequent prothrombin time determinations because hypothyroidism decreases and hyperthyroidism increases the sensitivity to oral anticoagulants
- Craniosynostosis may occur in infants due to excessive doses of thyroid hormone preparations
Cautions: Use cautiously in
- Renal impairment
- Cardiovascular disorders
- CAD
- Diabetes mellitus
- Diabetes insipidus
- Adrenal insufficiency
- Geriatrics
Pregnancy Category:A
Breastfeeding: Safety unknown. It is a normal component of human milk. No need to discontinue breastfeeding when liothyronine is required by the mother. As safety is unknown, an alternate drug may be preferred in nursing mothers. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 27 May 2011). Manufacturer advised caution.
Note: Usually only seen when excessive doses cause iatrogenic hyperthyroidism
- CNS: Insomnia, irritability, headache, nervousness, tremor
- CV: Arrhythmias, tachycardia, angina pectoris, cardiopulmonary arrest, MI, angina, hypotension, HTN, CHF
- GI: Abdominal cramps, diarrhea, vomiting
- DERM: Excessive sweating
- ENDO: Hyperthyroidism, menstrual irregularities
- METABOLIC: Weight loss, heat intolerance
- MUSC: Accelerated bone maturation in children
Pricing data from www.DrugStore.com in U.S.A.
- Liothyronine Sodium 5 MCG TABS [Bottle] (PADDOCK)
100 mcg = $75.99
300 mcg = $215.96 - Cytomel 5 MCG TABS [Bottle] (KING PHARMA)
100 mcg = $97.99
300 mcg = $267.97 - Liothyronine Sodium 50 MCG TABS [Bottle] (PADDOCK)
100 mcg = $153.98
300 mcg = $434.97 - Cytomel 50 MCG TABS [Bottle] (KING PHARMA)
100 mcg = $192.98
300 mcg = $578.95 - Liothyronine Sodium 25 MCG TABS [Bottle] (PADDOCK)
100 mcg = $95.99
300 mcg = $259.97 - Cytomel 25 MCG TABS [Bottle] (KING PHARMA)
100 mcg = $129
300 mcg = $371.95
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.
