Evaluation of the correct use of levothyroxine in patients with hypothyroidism
İntroduction: Standard treatment for hypothyroidism is replacement with synthetic Levothyroxine (LT4) sodium preparations. LT4 should be taken on an empty stomach at least 30 minutes before a meal, as maximal absorption occurs when taken on an empty stomach. Protein Pump Inhibitor (PPI), iron sulphate, calcium carbonate have been shown to reduce the absorption of LT4 when taken together with LT4. Therefore, patients receiving LT4 should be informed to take their drugs at least 4 hours before drugs that interact with thyroid hormone absorption.
Objective: The aim of this study is to evaluate the correct use of levothyroxine drug, which is widely used in the society, in patients with hypothyroidism, to reveal the reasons for misuse, and to associate the number of drugs used by patients, types and chronic diseases.
Material and method: Our study was conducted with a face-to-face questionnaire consisting of 18 questions in patients who applied to Recep Tayyip Erdoğan University Education and Research Hospital Endocrinology and Metabolic Diseases Polyclinic and Family Medicine outpatient clinic between 10-20 June 2020 and used LT4 due to any reason of hypothyroidism, and by obtaining patient consent.
Results: 103 patients, 15 men and 88 women, participated in our study. 103 (100%) of the patients participating in our study took their medication in the morning and stored it in the right place. 94 of them (91.3%) took their medication regularly. 92 of them (89.3%) used their medicine at least 30 minutes before the meal. 60 of the patients (58.25%) used their medication correctly. 18 (41.9%) of the 43 people who used wrong medication were using PPI, 7 (16.3%) calcium carbonate, 5 (11.6%) ferrous sulfate. When compared in terms of correct use, a statistically significant difference (p <0.05) was found in patients with gender, age, presence of hypertension, presence of chronic disease, number of drugs used, ppi use, and calcium carbonate use.
Conclusion: Our study highlights the insufficient knowledge about LT4 therapy among hypothyroid patients, the high prevalence of faulty applications, and the reasons for misapplication. These factors can lead to non-compliance and patient care not being optimal. It is important for physicians to inform patients about how to use the drug in terms of follow-up and treatment of the disease.
- Hollowell JG, Staehling NW, Flanders WD, et al. Serum TSH, T4, and thyroid antibodies in the United States population (1988 to 1994): National Health and Nutrition Examination Survey (NHANES III). J Clin Endocrinol Metab 2022;87:489-99.
- Aoki Y, Belin RM, Clickner R, et al. Serum TSH and total T4 in the United States population and their association with participant characteristics: National Health and Nutrition Examination Survey (NHANES 1999-2002). Thyroid 2007; 17:1211-7.
- Urgancıoğlu I, Hatemi H. Türkiye’de endemik guatr. Cerrahpaşa Tıp Fakültesi Nükleer Tıp ABD (Yayın No:14). İstanbul, Emek Matbaacılık, 1989.
- World Health Organization (WHO). Promoting Rational Use of Medicines: Core Components. WHO Policy Perspectives on Medicines no: 5. Geneva, 2002. https://apps.who.int/iris/handle/10665/67438 adresinden 03.11.2020 tarihinde erişilmiştir.
- Holloway K, vanDijk L. The World Medicines Situation 2011-Rational Use of Medicines. World Health Organization (WHO), Geneva. WHO/EMP/MIE/2011.2.2
- Bolk N, Visser TJ, Nijman J, et al. Effects of evening vs morning levothyroxine intake: a randomized double-blind crossover trial. Arch Intern Med 2010;170:1996– 2003.
- Rajput R, Chatterjee S, Rajput M. Can levothyroxine be taken as evening dose? Comparative evaluation of morning versus evening dose of levothyroxine in treatment of hypothyroidism. J Thyroid Res 2011;2011:505239.
- Bach-Huynh TG, Nayak B, Loh J, Soldin S, et al. Timing of levothyroxine administration affects serum thyrotropin concentration. J Clin Endocrinol Metab 2009;94:3905-12.
- Perez CL, Araki FS, Graf H, de Carvalho GA. Serum thyrotropin levels following levothyroxine administration at breakfast. Thyroid 2013;23:779–84.
- Elliott DP. Effect of levothyroxine administration time on serum TSH in elderly patients. Ann Pharmacother 2001;35:529-32.
- TİROİD HASTALIKLARI TANI VE TEDAVİ KILAVUZU 2020. http://temd.org.tr/admin/uploads/tbl_kilavuz/20200929134733-2020tbl_kilavuzf527c34496.pdf adresinden 11.11.2020 tarihinde erişilmiştir.
- Hays MT, Nielsen KR. Human thyroxine absorption: age effects and methodological analyses. Thyroid 1994;4:55-64.
- Benvenga S, Bartolone L, Squadrito S, et al. Delayed intestinal absorption of levothyroxine. Thyroid 1995;5:249-53.
- El-Kattan A, Varma M. Oral absorption, intestinal metabolism and human oral bioavailability. In “Topics on Drug Metabolism”. (Ed.) Paxton J. InTech, 2011. https://www.intechopen.com/books/topics-on-drug-metabolism/oral-absorption-intestinal-metabolism-and-human-oral-bioavailability- adresinden 13.12.2020 tarihinde erişilmiştir.
- Ilertz A. Food effects on drug absorption and dosage form performance. In: “Oral drug absorption prediction and assessment”. (Eds) Dressman JB, Reppas C. Second Edition. New York, Informa Healthcare USA, Inc, 2010.
- Kalra S, Unnikrishnan AG, Sahay R. The global burden of thyroid disease. Thyroid Res Pract 2013;10:89-90.
- Kalra S, Unnikrishnan AG, Baruah MP. Thyroid: Disorders of a lesser gland. Thyroid Res Pract 2013;10:45-6.
- Heisler M, Pietee JD, Spencer M, Kieffer E, Vijan S. The relationship between knowledge of recent HbA1c values and diabetes care understanding and self management. Diabetes Care 2005;28:816-22.
- Williams MV, Baker DW, Parker RM, Nurss JR. Relationship of functional health literacy to patients’ knowledge of their chronic disease. A study of patients with hypertension and diabetes. Arch Intern Med 1998;158:166-72.
- Özdemir Ö, Akyüz A, Doruk H, Geriatrik Hipertansif Hastaların İlaç Tedavisine Uyumları. Bakırköy Tıp Dergisi 2016; 12:4.
- Dağ E, Bilişsel Fonksiyonlar. Türkiye Klinikleri J 2013;6(4):16-20.
- Kojima T, Akishita M, Nakamura T, et al. Polypharmacy as a risk for fall occurrence in geriatric outpatients. Geriatr Gerontol Int 2012;12(3):425-30.
- Rezzan Gülhan. Yaşlılarda Akılcı İlaç Kullanımı. Okmeydanı Tıp Dergisi 2013;29 (Ek sayı 2):99-105. doi:10.5222/otd.supp2.2013.099.
- Mergen H, Tavlı T, Öngel K. Yaşlılarda Hipertansiyona yaklaşım. Türk Aile Hekimliği Dergisi 2010; 14(4):167-72.
- Zamfirescu I, Carlson HE. Absorption of levothyroxine when coadministered with various calcium formulations. Thyroid 2011;21:483-6.
- Fiaux E, Kadri K, Levasseur C, et al. Hypothyroidism as the result of drug interaction between ferrous sulfate and levothyroxine. Rev Med Interne 2010;31:e4–e5.
- Brown KS, Armstrong IC, Wang A, et al. Effect of the bile acid sequestrant colesevelam on the pharmacokinetics of pioglitazone, repaglinide, estrogen, estradiol, norethindrone, levothyroxine, and glyburide. J Clin Pharmacol 2010; 50:554-65.
- Irving SA, Vadiveloo T, Leese GP. Drugs that interact with levothyroxine: an observational study from the Thyroid Epidemiology, Audit and Research Study (TEARS). Clin Endocrinol (Oxf) 2015;82:136-41.
- Trifirò G, Parrino F, Sultana J, et al. Drug interactions with levothyroxine therapy in patients with hypothyroidism: observational study in general practice. Clin Drug Invest 2015; 35:187-95.
- Goel A, Shivaprasad C, Kolly A, et al. Frequent occurence of faulty practices, misconceptions and lack of knowledge among hypothroid patients. Journal of Clinical Diagnostic Reaserch 2017;11:7.
- Serin S, İlhan M, Ahcı S. Tiroid Hastalıklarında Bilinç Düzeyi. Şişli Etfal Hastanesi Tıp Bülteni 2016;50:3. doi: 10.5350/SEMB.20160412042738