Adverse Event Reporting in Patients with Thyroid Dysfunction Treated with Levothyroxine in Armenia. A Cross Sectional Pilot Study

Background and Aim. Currently two forms of levothyroxine are presented in pharmaceutical market of Armenia: Euthyrox and L-thyroxine. Local physicians have a choice of two different levothyroxine preparations, each of them with different dosage from 25 to 150mg. Oral levothyroxine (LT4) is the standard therapy for patients with hypothyroidism. The purpose of this report is to describe the adverse outcomes reported by endocrinologists, the frequent prescribers of levothyroxine, practicing in Armenia and to compare the rate of adverse reactions with data from different international research reports. Materials and methods. A Pharmacovigilance questionnaire was developed based on the literature reports to assess potential adverse events attributable to the use of levothyroxine products. Statistical Analysis Results were collected, interpreted and presented as percentages. Results. The study was with a cross-sectional design conducted in medical centers of Armenia using convenience sampling. The respondent parents of patients were selected using simple random sampling. Of the total 56 survey responses received, the majority 35 [63%]) reported no adverse events. The adverse effects were due to new or unexpected symptoms in 2 (25%), a TSH change alone in 1 (12%), or both in 6 (75%). Most the symptoms (5/8 [65%]) were consistent with thyrotoxicosis, arrhythmias were documented in three cases, while 35% (3/8) of cases had symptoms typical of hypothyroidism. Conclusions. Clinicians prescribing Euthyrox and L-thyroxine should be reminded that these products are from different manufacturers and patients/physicians should be made aware of all possible adverse reactions results, which could be different for these two products.