Usual Adult Dose for Hypothyroidism

Initial dose: 30 mg orally per day
Maintenance dose: Increase in increments of 15 mg per day every 2 to 3 weeks to a usual maintenance dose of 60 to 120 mg/day

Comments:

• This product has not been found by the US FDA to be safe and effective and the product labeling has not been approved.
• A lower dose of 15 mg/day is recommended in patients with long-standing myxedema, especially if cardiovascular impairment is suspected.
• Occurrence of angina is cause for dose reduction.
• Therapy is usually initiated at low doses, with increments which depend on the cardiovascular status of the patient.
• Failure to response to doses of 180 mg/day may suggest lack of compliance or malabsorption.

Usual Pediatric Dose for Hypothyroidism

0 to 6 months: 4.8 to 6 mg/kg/day orally
6 to 12 months: 3.6 to 4.8 mg/kg/day orally
1 to 5 years: 3 to 3.6 mg/kg/day orally
6 to 12 years: 2.4 to 3 mg/kg/day orally
Over 12 years: 1.2 to 1.8 mg/kg/day orally

Comments: This product has not been found by the US FDA to be safe and effective and the product labeling has not been approved.

Use: For the treatment of congenital hypothyroidism

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

Data not available

Dose Adjustments

Patients with cardiovascular disease: Initiate therapy at lower doses (i.e., 15 to 30 mg orally per day); when in such patients a euthyroid state can only be reached at the expense of aggravation of cardiovascular disease, thyroid hormone dosage should be reduced.

Elderly: This drug meets the American Society Beers Criteria due to concern about cardiac effects in patients 65 years or older; avoid use.

Precautions

US BOXED WARNING:

• TREATMENT OF OBESITY: Drugs with thyroid hormone activity, alone or together with other therapeutic agents, have been used for the treatment of obesity. In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction. Larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects.

Dialysis

Data not available

Other Comments

Storage requirements:

• Protect from light and moisture.

• Dosing of thyroid hormones is determined by the indication and must be individualized according to patient response and laboratory findings.
• This drug is for oral use; in acute, emergency conditions, injectable levothyroxine sodium (T4) may be given IV when oral administration is not feasible or desirable, as in the treatment of myxedema coma, or during total parenteral nutrition.
• Maintenance doses of 60 to 120 mg/day usually result in normal serum T4 and T3 levels; adequate therapy usually results in normal TSH and T4 levels after 2 to 3 weeks of therapy.
• Readjustment of dose should be made within the first 4 weeks of therapy, after proper clinical and laboratory evaluations, including serum levels of T4, bound and free, and TSH.

• Endocrine: Periodically obtain thyroid function tests; monitor glucose levels in patients with diabetes mellitus or insipidus.

• Report if at any point during the course of therapy any signs or symptoms of thyroid hormone toxicity, (e.g., chest pain, increased pulse rate, palpitations, excessive sweating, heat intolerance, nervousness), or any other unusual event.
• Partial hair loss may occur in pediatric patients during the first few months of treatment; however, this is usually transient.