Comparison of weekly vs daily dosing of levothyroxine for treatment of hypothyroidism in Ramadan – a pilot randomized controlled trial: preliminary results

• Main Authors: Zakaria, Nurul Aulia, Zakaria, Miza Hiryanti, Shahar, Mohammad Arif
• Format: Conference or Workshop Item
• Language: English; English; English
• Published: 2018
• Subjects: R Medicine (General); RC Internal medicine; RC648 Specialties of Internal Medicine-Diseases of The Endocrine Glands. Clinical Endocrinology
• Online Access: http://irep.iium.edu.my/67895/1/weekly%20vs%20daily%20thyroxine%20MAC9%202018.pdf; http://irep.iium.edu.my/67895/6/MAC9%20Oral%20Presentation%20%28ThyRa%29.pdf; http://irep.iium.edu.my/67895/7/MAC9_Oral%20Presentation_Acceptance%20Letter%20%23115%20%281%29.pdf; http://irep.iium.edu.my/67895/

INTRODUCTION : Muslim who fast during Ramadan find it difficult to take L-thyroxine as recommended every morning on empty stomach during sahur.The changes in eating patterns and gastric motility during Ramadan might affect the absorption and efficacy of L-thyroxine.This study is to compare the efficacy and safety of weekly vs daily dosing of L-thyroxine during Ramadan. METHODS : This was a randomized opened-label control trial during Ramadan 2017 held in a tertiary centre in Kuantan. Eight hypothyroid patients were randomized into weekly and daily arm (n=4 each arm).The weekly arm took 7x their usual thyroxine dose at least 30 minutes pre-sahur once a week whereas the daily arm took their usual thyroxine dose daily at least 2 hours after the last meal before bed.Thyroid function test (TSH, fT3, fT4), cardiac parameters (ecg, echo,holter), cognitive and psychological assessment were done at week zero.At week 2 repeated cardiac assessment were done for the weekly arm 24-hours after dosing.Thyroid function,cognitive and psychological function of both arm were reassessed at the end of week 4. RESULTS : The median age for weekly and daily group were 37(31.7,45.2) and 36(33.8,48.3) years old with majority(75%each arm) were diagnosed with post-radioiodine hypothyroidism.The median fT4 levels at week 4(weekly arm) was significantly higher compared from baseline [11.7(7.8,14.7) vs12.8(8.7,17.7)mmol/L;p=0.017 ].Nevertheless,it was not accompanied by increase fT3 or reduced TSH. Comparison of TSH, fT4 and fT3 between both arm at week 4 was not statistically significant . In term of toxicity,there was no significant increase in fT3 and fT4 level 24 hours post high doses of L-thyroxine in the weekly arm compared to baseline [fT3:4.3(4.2,4.9) vs4.7(3.6,5.7);p=0.70] and [fT4:11.7(7.8,14.7) vs 15.3(9.6,20.2);p=0.68]. None of the patients in both arm reported any side effects. CONCLUSION : From this pilot study, weekly L-thyroxine dosing during Ramadan appear to be efficient and safe,however a larger sample size is required to confirm the feasibility.