Twice-weekly dosing for thyroxine replacement in elderly patients with primary hypothyroidism

Area of Science:

• Endocrinology
• Geriatric Medicine
• Pharmacology

Background:

• Primary hypothyroidism is common in the elderly.
• Optimal dosing strategies for thyroxine replacement in older adults are crucial for adherence and efficacy.
• Daily thyroxine dosing can present challenges for some elderly patients.

Purpose of the Study:

• To compare the efficacy and safety of standard daily thyroxine therapy versus twice-weekly administration in elderly female patients with primary hypothyroidism.
• To assess biochemical thyroid hormone levels and tissue effects (systolic time intervals) under both dosing regimens.

Main Methods:

• A single-blind, randomized crossover study involving seven female patients (mean age 86 years) with confirmed primary hypothyroidism.
• Patients received standard daily or twice-weekly thyroxine (median 100 mcg) for one-month periods.
• Serum thyroid hormone levels (total triiodothyronine, free thyroxine), thyrotropin, and systolic time intervals were measured.

Main Results:

• Serum levels of thyroid hormones and thyrotropin remained similar between daily and twice-weekly thyroxine therapy.
• No statistically significant differences were observed in trough or peak hormone levels or systolic time intervals.
• Twice-weekly administration demonstrated effective biochemical thyroid hormone replacement without signs of tissue thyrotoxicosis.

Conclusions:

• Twice-weekly thyroxine therapy is an effective method for biochemical thyroid hormone replacement in elderly patients with primary hypothyroidism.
• This regimen offers a viable alternative for patients experiencing poor compliance with daily dosing.
• Supervised twice-weekly thyroxine should be considered for improving treatment adherence in this population.