Endocrine Abstracts

Objectives

Adherence to treatment is one of the most important parameters that affect the success of the treatment in hypothyroidism. We aimed to evaluate the use and adherence to treatment and determine the factors that are related to adherence in patients on levothyroxine therapy.

Materials and Methods

Patients older than 18 years old and using levothyroxine for hypothyroidism were recruited. Demographical, sociocultural and clinical statuses of patients were determined. The practices of using levothyroxine and compliance were evaluated through a questionnaire. Thyroid hormones and antibodies were obtained from medical records. Those who answered the frequency of not using/skipping the drug as never/rarely, sometimes and frequently/often were grouped as high, medium and low adherence, respectively. Data of high, medium and low adherence patients were compared.

Results

A total of 335 patients – 282 (84.18%) female and 53 (15.82%) – male were included. Mean age was 47.36±12.50. 330 (98.50%) patients were taking levothyroxine in the morning and 332 (99.10%) were taking fast. The period between the drug and meal was 15 min in 66 (19.88%), 30 min in 170 (51.20%), 45 min in 25 (7.53%), at least 1 h in 63 (18.98%) patients, while 8 (%2.41) patients were taking it just before or during the meal. Among 145 (45.03%) patients who use a medication that may interfere with the absorption of levothyroxine, 66.66% were using it in less than 2 h of levothyroxine. There were 218 (65.08%) high, 98 (29.25%) medium and 19 (5.67%) low adherence patients. Drug adherence was not associated with sex, age, marrital and working status, smoking, alcohol use, the cause and duration of hypothyroidism, presence of comorbid disease and thyroid hormones. The rate of patients graduated from primary school was higher in low adherence and rate of patients graduated from university was higher in high adherence groups (P = 0.008). Familial history of thyroid disease was associated with high adherence (P = 0.013).

Conclusion

We showed that drug adherence is medium or low in 34.92% of hypothyroid patients, and education level and familial thyroid disease were related with high adherence. Although majority of patients take levothyroxine at fast, 22.29% eat less than 30 min after taking the drug. In addition, a considerable amount of patients using medications that inhibits the absorption of levothyroxine did not leave required time between two medications. For effective treatment of hypothyroidism, it is important to increase drug compliance and inform patients about hypothyroidism and levothyroxine.