Treatment of dopamine-dependent shock with triiodothyronine

At the present time dopamine is the most frequently used treatment in patients with septic shock. The effects of dopamine are mediated by alpha-, beta- and dopaminergic receptors. It has been suggested that these receptors are controlled by triiodothyronine (T3). In acute septic shock circulating T3-concentrations are decreased. We have, therefore, treated in a preliminary study 11 such patients with T2-replacement by continuous infusion of T3 (100-200 micrograms/24h). Dopamine dependence was terminated. In all patients there was an increase of arterial blood pressure (BP) within 24 hrs (systolic BP rose by 34 +/- 4.2 mmHg, diastolic BP by 14.0 +/- 8.2 mmHg, resulting in an increase of the mean BP by 25 +/- 6.1 (SEM mmHg). The pulse rate was not influenced suggesting an effect on minute volume. A hypothesis is offered which explains the T3-effects as a result of its decarboxylation to a dopaminergic iodothyronine which is disturbed during the "low T3-syndrome".