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Comparison of Two Timings of Levothyroxine Intake in Hypothyroid Patients: A Cross-over Randomized Control Trial
Sponsor: Elyes Kamoun
Summary
Primary hypothyroidism is a common condition, affecting nearly 10% of the general population. Its treatment is levothyroxine, a synthetic thyroid hormone with a half-life of nearly eight days. Optimal absorption of levothyroxine occurs when it is taken on an empty stomach. It is generally recommended to take the medication in the morning, at least 30 minutes before breakfast. However, this treatment regimen can be challenging for some patients. Missed doses constitute a problem, leading some patients to choose another timing of intake. Other patients may find it difficult to wait before breakfast, resulting in suboptimal absorption, increased TSH levels, and poor disease control. Despite these challenges, American Thyroid Association guidelines recommend taking levothyroxine in the morning, in a fasting state, as the preferred timing of intake. They also suggest bedtime intake as a reasonable alternative, as long as the medication is taken at least three hours after the evening meal. As optimal levothyroxine absorption depends primarily on intake on an empty stomach, alternative treatment schedules could be considered, as long as the fasting requirement is respected to maintain stable TSH levels. To our knowledge, only one study has compared daytime levothyroxine intake, three hours after breakfast, with morning and bedtime intake. There was no significant difference in TSH levels between the different schedules. Confirming the stability of TSH levels with different schedules would offer patients with hypothyroidism greater flexibility in treatment timing, better adapted to their lifestyle habits. The aim of our study is to compare serum TSH levels according to two timings of levothyroxine intake in patients with hypothyroidism. Secondary objectives are to assess treatment adherence, quality of life, and patients' preferred timing of levothyroxine intake.
Official title: A Cross-over Randomised Control Trial Comparing Two Timing of Levothyroxin Intake (Fasting Versus Three Hours After Breakfast) in Well-controlled Hypothyroid Patients: Control of the Disease, Quality of Life and Satisfaction
Key Details
Gender
All
Age Range
18 Years - 65 Years
Study Type
INTERVENTIONAL
Enrollment
102
Start Date
2025-07-24
Completion Date
2026-12
Last Updated
2026-10-28
Healthy Volunteers
No
Conditions
Interventions
Levothyroxine Pill
Levothyroxine will be taken in a fasting state in the morning, with a waiting time of at least 30 minutes before breakfast. TSH levels will be measured after eight weeks. There will be no washout period. During the second period, levothyroxine will be taken three hours after breakfast, with at least 30 minutes before any further oral intake. TSH levels will be measured after eight weeks.
Levothyroxine Pill
Levothyroxine will be taken three hours after breakfast, with at least 30 minutes before any further oral intake. TSH levels will be measured after eight weeks. There will be no washout period. During the second period, levothyroxine will be taken in a fasting state in the morning, with a waiting time of at least 30 minutes before breakfast. TSH levels will be measured after eight weeks.
Locations (1)
La Rabta hospital
Tunis, Tunis Governorate, Tunisia