Important Safety Information and Indications

WARNING: Thyroid hormones, including LEVOXYL, either alone or with other therapeutic agents, should not be used for the treatment of obesity or for weight loss. 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.

LEVOXYL is contraindicated in patients with untreated subclinical or overt thyrotoxicosis of any etiology, acute myocardial infarction, or uncorrected adrenal insufficiency. LEVOXYL is contraindicated in patients with hypersensitivity to any of its inactive ingredients.

LEVOXYL should not be used in patients with nontoxic diffuse goiter or nodular thyroid disease if serum TSH level is already suppressed. If the TSH is not suppressed, LEVOXYL should be used with caution and monitoring for evidence of hyperthyroidism.

LEVOXYL should not be used for the treatment of male or female infertility unless this condition is associated with hypothyroidism.

LEVOXYL has a narrow therapeutic index. Careful dosage titration is necessary to avoid the consequences of over- or under-treatment such as effects on growth and development, cardiovascular function, bone metabolism, reproductive function, cognitive function, emotional state, gastrointestinal function, and glucose and lipid metabolism.

Decreased bone mineral density (BMD) has been associated with long term LEVOXYL therapy in women. It is recommended that LEVOXYL be given in the minimum dose necessary to achieve the desired response.

LEVOXYL should be initiated at lower doses in the elderly and in patients with cardiovascular disorders.

Many drugs affect thyroid hormone pharmacokinetics and metabolism. Thyroid hormones also affect the pharmacokinetics and action of other drugs. The prescriber should be aware of this fact and should consult appropriate reference sources.

Acute massive overdosage of LEVOXYL may be a life-threatening emergency. Symptomatic and supportive therapy should be instituted immediately.

Adverse reactions associated with LEVOXYL are primarily those of hyperthyroidism due to therapeutic overdosage: fatigue, increased appetite, weight loss, heat intolerance, fever, excessive sweating, headache, hyperactivity, nervousness, anxiety, irritability, emotional lability, insomnia, tremors, muscle weakness, palpitations, tachycardia, arrhythmias, increased pulse and blood pressure, heart failure, angina, myocardial infarction, cardiac arrest, dyspnea, diarrhea, vomiting, abdominal cramps, hair loss, flushing, menstrual irregularities, impaired fertility, and rarely seizures. Also in children: pseudo tumor cerebri, slipped capital femoral epiphysis; overtreatment may result in craniosyntosis, and premature closure of the epiphyses.

When LEVOXYL was not taken with water the following adverse events have been reported: choking, gagging, tablet stuck in throat and dysphagia.


LEVOXYL is indicated for hypothyroidism—as replacement or supplemental therapy in congenital or acquired hypothyroidism of any etiology, except transient hypothyroidism during the recovery phase of subacute thyroiditis. Specific indications include: primary (thyroidal), secondary (pituitary), and tertiary (hypothalamic) hypothyroidism and subclinical hypothyroidism.

LEVOXYL is indicated for pituitary TSH suppression—in the treatment or prevention of various types of euthyroid goiters including thyroid nodules, subacute or chronic lymphocytic thyroiditis (Hashimoto’s thyroiditis) multinodular goiter and as an adjunct to surgery and radioiodine therapy in the management of thyrotropin-dependent well-differentiated thyroid cancer.

Please see full Prescribing Information, including BOXED WARNING.