[Thyroid function tests in acute drug intoxication].

Abstract

It is well known that thyroid function tests may be changed in non-thyroidal illnesses. To understand the influence of acute drug intoxication on thyroid function tests, 31 drug intoxicated patients without previous thyroid disorders and systemic diseases were included in our study. T3, T4, TSH, and resin T3 uptake were checked as soon as they arrived at our emergency service and were compared to that of 58 healthy volunteers. Within 31 patients, 14 were intoxicated by organophosphorous compounds, 6 by sedatives and hypnotics, 3 by strong acid, 2 by paraquet, 2 by rodenticides (warfarin), 2 by lysol and the other 2 were intoxicated by acetaminophen. The mean T3 and TSH levels were significantly lower in the drug intoxicated group. Among the 31 patients, 14 (45.2%) had a low T3, 2 (6.5%) had a low T3 and T4, and 6 (19.3%) had an elevated T4. All of the patients with an elevated T4 were intoxicated by organophosphates. If we divided the 31 patients into 2 subgroups: organophosphate intoxicated group and non-organophosphate intoxicated group, T4 and FT4I were significantly higher in the former group. Thyroid function tests became normal after treatment in 27 patients, discharged in good general condition. T3 and T4 became extremely low in 4 patients before they expired. The present study confirms that acute drug intoxication, like other non-thyroidal illnesses, affects thyroid function tests. Acute organophosphate intoxication may cause transient hyperthyroxinemia.