Related Experiment Videos
Variations in serum thyroxine concentrations with time after an oral replacement dose
Clinical Nuclear Medicine
|May 1, 1987
Summary
Thyroid hormone (thyroxine) levels in healthy men peaked 2 hours after taking oral tablets and remained elevated for 10 hours. These thyroxine fluctuations are crucial for interpreting lab results in patients on thyroid replacement therapy.
Area of Science:
- Endocrinology
- Pharmacokinetics
- Clinical Chemistry
Background:
- Thyroxine replacement therapy is common for hypothyroidism.
- Understanding the pharmacokinetic profile of oral thyroxine is essential for effective treatment.
- Variability in absorption and metabolism can impact serum hormone levels.
Purpose of the Study:
- To investigate the time course of serum thyroxine concentrations after oral administration of commercial thyroxine tablets.
- To determine the peak and duration of elevated thyroxine levels.
- To assess the clinical relevance of observed thyroxine fluctuations.
Main Methods:
- Eight healthy male volunteers participated in the study.
- Serum thyroxine levels were measured sequentially after oral intake of two different thyroxine tablet brands.
- Data analysis focused on time to peak concentration and return to baseline.
Main Results:
- Serum thyroxine concentrations peaked at 2 hours post-administration in all subjects.
- Elevated thyroxine levels persisted for up to 24 hours.
- Statistically significant elevations were observed between 2 and 10 hours.
Conclusions:
- Oral thyroxine exhibits a prolonged absorption profile.
- Observed serum thyroxine fluctuations may influence the interpretation of laboratory results in patients.
- Timing of blood draws is critical when monitoring thyroxine levels in patients undergoing replacement therapy.