ATLANTA -- Liquid formulations of levothyroxine offer the possibility of allowing patients with hypothyroidism to take their medication with meals or coffee and skip the currently recommended 30- to 60-minute waiting period before doing either, new data suggest.
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Because food, coffee, and certain medications can interfere with intestinal absorption of levothyroxine (also known as LT4), current guidelines recommend that the drug be taken in a fasting state, typically 30-60 minutes before breakfast. However, compliance may be difficult for some patients.
Now, a potential solution may come from new evidence that liquid levothyroxine formulations that bypass the gastric dissolution phase of absorption may mitigate the interference with food and coffee.
Findings from two bioavailability studies showing no difference in comparisons of Thyquidity (levothyroxine sodium oral solution, Vertice Pharma) with or without waiting periods before consuming coffee or a high-fat meal were presented at the annual meeting of the Endocrine Society (ENDO 2022), by Vertice Pharma Medical Director Kris Washington, PharmD.
And just last month, similar data were published in Thyroid for another levothyroxine oral solution, Tirosint-SOL (IBSA). No difference in pharmacokinetic properties were found with this product with a shorter versus a longer waiting period before consuming a high-fat meal.
Liquid thyroxine may be less affected by food/drink but is expensive
Both products have been approved by the U.S. Food and Drug Administration, but current labeling for both still calls for a 30- to 60-minute waiting period between taking the medication and eating or drinking. Thyquidity is an oral solution of 100 µg/mL levothyroxine sodium that has been shown to be bioequivalent to one of the most popular branded levothyroxine tablets, Synthroid (AbbVie), under fasting conditions. Tirosint-SOL is also an oral solution that comes in 15 different dosage ampules.
“It is important to note that while these findings are exciting and encouraging, we do want you to continue to follow the current FDA-approved label for Thyquidity, recommending that it be taken on an empty stomach 30-60 minutes prior to breakfast and that patients continue to follow all other label instructions,” Dr. Washington said during a press briefing at ENDO 2022.
When asked whether the new data would be submitted to the FDA for a possible amendment to this message, she replied: “We’re still discussing that. We’re exploring all options. ... This is fairly new data. ... It makes sense and certainly solves a lot of the challenges for people who can’t swallow or don’t choose to swallow, or the challenges of splitting or crushing with tablets.”
Asked to comment, Benjamin J. Gigliotti, MD, a clinical thyroidologist at the University of Rochester, New York, told this news organization: “Liquid levothyroxine has the potential to be a clinically useful formulation,” noting that these recent data corroborate prior findings from Europe and elsewhere that liquid levothyroxine is absorbed more rapidly and thus may be less impacted by food or beverages.
However, Dr. Gigliotti also pointed out, “I don’t think malabsorption is a major contributor to suboptimal treatment because if [patients] malabsorb the hormone, we typically just increase their dose a little bit or ask them to take it separately, and that works just fine for most people.”
And the higher cost of the liquid products is a major issue, he noted.
A quick search on GoodRx shows that the lowest price of Tirosint-SOL is $115.52 for a 1 month supply and Thyquidity is $181.04/month. “In the few patients where I tried to obtain Tirosint-SOL, it was not covered by insurance, even with a prior authorization,” Dr. Gigliotti commented.
In contrast, generic levothyroxine tablets are about $4/month, while a common brand name of levothyroxine tablets are $47.81/month.
“Until these liquid formulations are more widely covered by insurance for a reasonable copay, or come down in price compared to generic levothyroxine tablets, most of my patients have voiced that they’d rather deal with the inconveniences of a tablet compared to higher medication cost, especially with rising economic insecurity imposed by the COVID-19 pandemic and recent world events,” Dr. Gigliotti said.