Adequate restitution in primary hypothyroidism depending on levothyroxine formulations

Area of Science:

• Endocrinology
• Pharmacology
• Public Health

Background:

• Primary hypothyroidism affects 3.8%-4.6% of the population.
• Approximately 40% of patients on levothyroxine treatment exhibit abnormal thyroid-stimulating hormone (TSH) levels.

Purpose of the Study:

• To investigate the prevalence of euthyroid sick syndrome in primary hypothyroidism patients undergoing levothyroxine treatment.
• To assess if the number of available levothyroxine formulations influences treatment adequacy.

Main Methods:

• A descriptive, comparative cohort study involved 350 primary hypothyroidism patients on stable levothyroxine doses for over six months.
• Exclusion criteria included use of liothyronine/levothyroxine mixtures, postsurgical hypothyroidism, pregnancy, breastfeeding, or mental illness.
• Two clinics were compared: Clinic 1 (public) with only 100 µg levothyroxine, and Clinic 2 (private) with 25, 50, 75, and 100 µg formulations.

Main Results:

• Clinic 1 (public) achieved appropriate dosing in 63% of patients, while Clinic 2 (private) achieved it in 75% (p = 0.033).
• 39% of patients at the public clinic received an inappropriate levothyroxine dose, compared to 25% at the private clinic.

Conclusions:

• The availability of multiple levothyroxine formulations may be a significant factor in achieving adequate treatment restitution.
• Limited drug formulation options in public healthcare settings could contribute to a higher risk of inadequate primary hypothyroidism management.