Twice or thrice weekly levothyroxine provides similar rates of adherence and post-Ramadan euthyroidism compared to daily levothyroxine during Ramadan fasting.

Background: Having to take levothyroxine (L-T4) on a daily basis, on an empty stomach is burdensome and may impair adherence, especially during Ramadan fasting. A long half-life and autoregulation of thyroid hormone levels allows for twice or thrice weekly administration of L-T4. This study aims to establish twice or thrice weekly L-T4 dosing as a convenient and effective practice during Ramadan fasting.

Methods: The study included 2 groups; twice or thrice weekly (TTW) group included patients assigned to take L-T4 twice or thrice a week, and standard daily dosing (SDT) group included patients assigned to take L-T4 daily. Patients freely chose between three L-T4 regimens: before Iftar, before Suhor, or before the next fast. Thyroid status was assessed before and within 6 weeks after Ramadan. Only euthyroid patients were included.

Results: TTW group included 57 patients, while SDT group included 91 patients. Pre-Ramadan TSH in TTW group (1.80 ± 0.88 µIU/L) was higher compared to SDT group (1.39 ± 0.72 µIU/L) [P = 0.003]. Similar adherence rates were observed in both groups, 96.5% in TTW group versus 89% in SDT group, [P = 0.13]. similar rates of post-Ramadan euthyroidism were also found in both groups, 91.2% in TTW group versus 94.5% in SDT group, [P = 0.509]. TTW group preferred regimen 1 (64.9%) significantly more than SDT group (35.2%) [P = 0.001].

Conclusion: Twice or thrice weekly levothyroxine results in similarly high rates of adherence (96.5%) and post-Ramadan euthyroidism (91.2%) compared to daily levothyroxine during Ramadan fasting.