Drinking coffee does not hinder absorption of liquid thyroid medication

Although current product labels and treatment guidelines recommend that patients take thyroid hormone replacement therapy on an empty stomach, new research suggests drinking coffee does not affect the absorption of a liquid formulation of levothyroxine (LT4).

A new study conducted by Vertice Pharma confirms the absorption of an oral levothyroxine sodium solution (Thyquidity® 100mg/ 5mL) was not affected by consuming coffee 5 minutes after the dose, according to research being presented Saturday at ENDO 2022, the Endocrine Society's annual meeting in Atlanta, Ga.

That's potentially good news for patients who have previously been told to take levothyroxine 30-60 minutes before coffee to avoid a drug interaction.

"The lifestyle adjustment required to adhere to these recommendations is often burdensome to the patient and may lead to difficulty in achieving ideal thyroid hormone levels, resulting in both patient and provider frustration," said Kris Washington, PharmD, Medical Director of Vertice Pharma in Berkeley Heights, N.J., which manufactures the medication.

Washington and colleagues sought to understand the absorption profile of the levothyroxine sodium oral solution administered with coffee compared to fasting conditions in a bioavailability study in 40 healthy adults.

Researchers administered a single 600 μg oral dose of LT4 solution 5 minutes before having adults drink 8 ounces of American coffee (without milk or sweeteners) or under fasting conditions in each study period. They collected blood samples to measure thyroid levels for 48 hours after each drug administration, which was followed by a 40-day wash-out between study periods.

These results confirm the bioequivalence of a single oral 600 μg dose of the levothyroxine sodium oral solution taken 5 minutes before coffee or under fasting conditions.

"The results demonstrate that the absorption of levothyroxine sodium oral solution was not affected by the consumption of coffee, potentially offering patients and providers more dosing flexibility," Washington said.