DYNAMICS OF THYROID AXIS HORMONE LEVELS IN PATIENTS WITH AFFECTIVE SPECTRUM DISORDERS DURING THERAPY WITH VENLAFAXINE

Abstract

Background. Scientific literature data confirm the relevance of studying the effect of antidepressants on the functioning of the thyroid axis in patients with affective disorders. At the same time, many aspects of this problem remain poorly understood. Aim of the study. Clarification of the characteristics of the dynamics of the levels of hormones of the hypothalamic5pituitary5thyroid (HPT) axis in patients with affective disorders during therapy with venlafaxine. Materials and methods. The study included 72 patients: 24 men and 48 women aged 20 to 55 years (mean age 43.8 ± 14.2 years) with affective spectrum disorders (F31.3; F33.1; F41.2). Therapy was carried out with venlafaxine at a dose of 75-150 mg/day, as a monotherapy. The average daily dosage was 141.16 ± 52.3 mg/day. The studies of thyroid5stimulating hormone (TSH), triiodothyronine (T3), free thyroxine (T45free) were carried out before the start of therapy, after 14 days and after 28 days of therapy. Results. Venlafaxine therapy for 4 weeks was effective in assessing responsiveness (more than 50 % reduction on the HDRS scale) in all patients studied. The baseline values of TSH, T3 and T4 made it possible to ascertain the presence of subclinical hypothyroidism in 8.3 % of patients with bipolar affective disorder (BAD) and in 6.25 % with recurrent depressive disorder (RDD). In patients with bipolar disorder, there was an improvement in the functioning of the GGT axis, as indicated by a significant (p = 0.018) increase in the level of triiodothyronine (T3) by day 28 of therapy, as well as significant negative correlations between TSH and T3 at stages 2 and 3 of the study (r = -0.61, p = 0.0034; r = -0.61; p = 0.0029, respectively), despite slight fluctuations in the direction of decreasing T4 levels in 25 % of patients. In patients with recurrent depressive disorder, by the 14th and 28th days of therapy, the number of patients with a decrease in the levels of peripheral hormones increased against the background of fairly stable TSH indices, which may indicate the presence of a functional hypothyroid state. In patients with anxiety depressive disorder (ADD), by the 14th day, only T4 levels (fluctuations in the reference range) significantly decreased against the background of minor fluctuations in TSH and T3. Conclusion. The study showed that venlafaxine, in addition to being highly effective, was shown to be safe in terms of its effect on the thyroid axis. This is indicated by the normative indicators of the average values of the hormone HPT axis in the course of therapy. In addition, there was a normalization of elevated background TSH values in patients of all groups. The decrease in the level of peripheral hormones in a number of patients with recurrent depressive disorder may be associated, in all likelihood, with the underlying disease.