Misuse of levothyroxine and the rate of achieving target thyroid-stimulating hormone in levothyroxine treatment

Abstract

Objectives: The aim of the present study was to investigate the misuse of levothyroxine treatment in patients with hypothyroidism.

Methods: Patients who received levothyroxine treatment were included in the study. Age, gender, duration of medication use, Thyrotropin (TSH) level, regular use of medication, time and manner of taking medication, drug storage conditions and use of additional medication were recorded. Taking the medication on a full stomach or in the evening, occasional use of medication, storing the medicine in the refrigerator, and the use of additional medication were classified as misuse of levothyroxine treatment. According to the levels of TSH: 0.4-4.5 mIU/L was considered a normal dose, while 4.5 mIU/L and above was considered insufficient, and 0.4 mIU/L and below was considered as high dose.

Results: Patients who received levothyroxine pill were included in the study (average age: 53 +/- 14 years, average duration of medication use: 48 +/- 50 months and females/male ratio: 363/44). 323 (79.4%) of patients stated that they take the medicine regularly. Levothyroxine dosage was found to be sufficient in 235 patients (57.7%), insufficient in 101 patients (24.8%) and high in 71 patients (17.4%). Among the 84 patients which were identified as misusing, 66 (16.2%) patients were taking the medicine on a full stomach, 12 (2.9%) patients were taking the medicine in the evening, 11 patients (2.7%) were storing the medicine in the refrigerator, 17 (4.2%) patients were taking the medicine occasionally, and 21 (5.1%) patients were using one or more additional medications.

Conclusions: Taking the medication on a full stomach or in the evening, occasional use of medication, storing the medicine in the refrigerator, and the use of additional medications were the major factors for insufficient TSH levels. Appropriate usage of levothyroxine pills is crucial for successful treatment.