[The effect of long-term treatment with nadolol on serum levels of thyroid hormones and thyrotropin in patients with hypertension].

In 20 males with Stage II hypertensive disease, effects of 2-week-, 2-, and 6-month monotherapy with nadolol given in doses 40 to 160 mg daily were examined on the levels of thyroidal hormones (T3 and T4) and thyroid-stimulating hormone. At the all stages of the therapy, the mean values of the examined parameters were significantly unchanged. Nadolol was found to cause a decrease in T3 concentrations at its high baseline values (r = -0.57; p less than 0.05) and in doses greater than 40 mg daily. With reduced T3 levels, there were elevated T4 levels in most cases. An inverse relationship was established between the altered serum T3 levels and the thyroid-stimulating hormone concentration.