The signs and symptoms of overdosage are those of hyperthyroidism. [See WARNINGS AND PRECAUTIONS and ADVERSE REACTIONS] In addition, confusion and disorientation may occur. Cerebral embolism, shock, coma, and death have been reported. Seizures have occurred in a 3-year-old child ingesting 3.6 mg of levothyroxine. Symptoms may not necessarily be evident or may not appear until several days after ingestion of levothyroxine sodium.

Treatment of Overdosage

Levothyroxine sodium should be reduced in dose or temporarily discontinued if signs or symptoms of overdosage occur.

To obtain up-to-date information about the treatment of overdose, a good resource is the certified Regional Poison Control Center. In managing overdosage, consider the possibility of multiple drug overdoses, interaction among drugs, and unusual drug kinetics in the patient.

In the event of an overdose, appropriate supportive treatment should be initiated as dictated by the patient's medical status.

• Do not give TIROSINT to anyone who may be unable to swallow a capsule, including young children (generally under 6 years of age) because of the risk of aspiration.
• Levothyroxine is also contraindicated in patients with:
  • Acute myocardial infarction: administration of levothyroxine in this setting can exacerbate angina and increase the risk of arrhythmia.
  • Uncorrected adrenal insufficiency since thyroid hormones may precipitate an acute adrenal crisis by increasing the metabolic clearance of glucocorticoid [See WARNINGS AND PRECAUTIONS].

Last reviewed on RxList: 3/14/2012
This monograph has been modified to include the generic and brand name in many instances.