Oral L-thyroxine liquid versus tablet in patients with hypothyroidism without malabsorption: a prospective study

Area of Science:

• Endocrinology
• Pharmacology

Background:

• Levothyroxine (L-T4) is a standard treatment for hypothyroidism.
• Data on the effectiveness of liquid L-T4 formulations in patients without malabsorption is limited.
• Comparing liquid L-T4 to tablet formulations is crucial for optimizing treatment.

Purpose of the Study:

• To compare the effectiveness of liquid L-T4 versus L-T4 tablets in hypothyroid patients without malabsorption or drug interference.
• To evaluate the impact of switching from L-T4 tablets to liquid L-T4 on thyroid hormone levels.

Main Methods:

• A study involving 152 hypothyroid patients without malabsorption or drug interference.
• Patients were switched from L-T4 tablets to an equivalent dosage of liquid L-T4, administered 30 minutes before breakfast.
• Serum TSH, FT4, and FT3 levels were monitored at 1-3 months and 5-7 months post-switch.

Main Results:

• Serum TSH levels significantly declined after switching to liquid L-T4 at both follow-up points (P < 0.05 and P < 0.01).
• Free thyroxine (FT4) and free triiodothyronine (FT3) levels showed no significant changes.
• Liquid L-T4 demonstrated superior TSH control compared to L-T4 tablets.

Conclusions:

• Liquid levothyroxine (L-T4) is more effective than L-T4 tablets in managing TSH levels in hypothyroid patients without malabsorption.
• The liquid formulation offers a potentially improved therapeutic option for certain hypothyroid patient populations.
• Further research may explore long-term efficacy and patient-reported outcomes.