FDA Approves 2 Label Changes to Levothyroxine Sodium for the Treatment of Hypothyroidism

The FDA has approved 2 changes to the label of levothyroxine sodium (Tirosint-SOL, IBSA), an oral solution that is aimed to treat hypothyroidism. The first change included the use of levothyroxine sodium combined with proton pump inhibitor (PPI) therapy. The second change included timing to administer levothyroxine sodium.

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The oral solution of levothyroxine sodium was created with a formulation of levothyroxine (LT4). The approved label changes will ensure the differences between levothyroxine sodium and other forms of levothyroxine therapies.

Hypothyroidism is defined as an endocrine disorder that causes a deficiency in the thyroid hormone, impacting more than 24.5 million individuals in the United States. Among the many individuals living with hypothyroidism, women aged 40 years and over, along with elderly men and women are more commonly affected. Symptoms include fatigue, forgetfulness, depression, constipation, muscle cramps, weight gain, dry skin, and hair loss.

Levothyroxine sodium was deemed as a suitable treatment option for hypothyroidism because it is a synthetic version of a hormone that is normally formed by the thyroid gland. The treatment has a range of 15 dosage strengths in the United States—the widest variety available. Reported adverse effects of the treatment included arrhythmias, myocardial infarction, dyspnea, muscle spasm, headache, nervousness, irritability, insomnia, tremors, muscle weakness, increased appetite, weight loss, diarrhea, heat intolerance, menstrual irregularities, and skin rash.

The press release noted that approved label changes were caused by the results of 2 clinical studies that found an absence of interaction between levothyroxine sodium and PPI, and it demonstrated the same results when administered 15 minutes before eating breakfast, and 30 minutes before eating breakfast.

“The availability of this liquid oral levothyroxine formulation, which is not affected by [PPI] and can be taken just 15 minutes before breakfast, is a real plus for hypothyroid patients and health care practitioners,” said Michael Scully, head of commercial operations, IBSA USA, in a press release. “These new label changes reinforce Tirosint-SOL’s position as a simple, convenient, and clean LT4 therapy with only 3 ingredients.”

The press release noted that the approval marks levothyroxine sodium as the only FDA-granted LT4 therapy that does not have a labeled interaction with PPIs and can be taken 15 minutes prior to eating breakfast.

“Appropriate administration of levothyroxine can be difficult for patients, given the multiple therapies that can interfere with its absorption and the requirement to administer it in a fasting state,” said Francesco Celi, MD, University of Connecticut School of Medicine, in a press release. “The opportunity to provide patients living with hypothyroidism with a medication that is easier to use because it is not affected by PPIs, which are commonly used acid-reducing agents, and can be taken 15 minutes before breakfast, should be of interest to clinicians as it may increase adherence and improve therapeutic outcomes.”

Reference

Food And Drug Administration Grants Two New Label Changes To Tirosint®-Sol (Levothyroxine Sodium) Oral Solution. Business Wire. News release. December 4, 2023. Accessed December 5, 2023. https://www.businesswire.com/news/home/20231204748430/en.