Effect of intravenous dopamine infusion on pituitary and thyroid function and on nephroprotection

INTRODUCTION Catecholamines, including dopamine, are used in cardiac intensive care.
OBJECTIVES The aim of the study was to assess the effect of intravenous dopamine infusion on the function of pituitary gland in patients with acute cardiac failure. We analyzed changes in the serum levels of thyroid-stimulating hormone (TSH) and adrenocorticotropic hormone (ACTH), as well as potential nephroprotection.
PATIENTS AND METHODS The study involved 29 patients with chronic decompensated heart failure (New York Heart Association class III/IV; mean age 77.4 ±13.3 years). Dopamine was administered intravenously in doses varying from 1 to 5 μg/kg/min. Measurements of TSH, free triiodothyronine (FT3), free thyroxine (FT4), and ACTH were taken directly before dopamine infusion, after 12 hours of continuous infusion, and 12 hours after the 72-hour infusion was completed.
RESULTS Serum FT3 levels were significantly higher before dopamine infusion than at 12 hours post infusion (5.12 ±1.16 vs. 4.27 ±0.89 pmol/l, P <0.005). Serum FT4 levels before the infusion were significantly higher than after 12 hours of continuous infusion as well as after 12 hours post infusion (18.79 ±5.33 vs. 17.06 ±4.61 pmol/l, P <0.05; 18.79 ±5.33 vs. 16.26 ±4.53 pmol/l, P <0.05, respectively). There were no statistically significant differences between serum TSH and ACTH levels or in creatinine clearance before, during, and 12 hours post infusion.
CONCLUSIONS Intravenous infusion of dopamine may downregulate endocrine thyroid function; however, it has no significant effect on the pituitary gland-derived TSH and ACTH. There was no significant nephroprotective effect of low-dose dopamine infusion in patients with chronic decompensated chronic heart failure.