[Propylthiouracil-induced overt hepatic injury in patients with hyperthyroidism]

To study the incidence, clinical features and related factors of propylthiouracil (PTU)-induced hepatic injury in patients with hyperthyroidism.

A prospective study were carried out in 70 patients of hyperthyroidism with normal liver function. Every patient was treated with PTU 300 mg/d until the thyroid functions recovered to normal, following by decease and maintenance PTU dose in period of six months. Liver function, including serum levels of alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), total bilirubin (TBIL) and direct bilirubin (DBIL), thyroid function (serum thyroxine, triiodothyronine, free thyroxine, and free triiodothyronine and thyrotropin) and blood routine items were measured before therapy and once a month for six months after PTU therapy was begun.

Sixty-four cases of 70 patients completed the therapy for 6 months. Hepatic injury developed in 33 patients (51.6%). Asymptomatic, transient hepatic injury was shown in 22 patients (34.4%). Slight symptomatic hepatic injury occured in 6 cases (9.4%) and overt hepatic injury in 5 patients (7.8%) after PTU administration. However, all the patients who developed overt hepatic injury did not stop PTU. Hepatic function returned normal one month after stopping PTU. No one finally suffered from viral hepatitis and autoimmune hepatitis in patients of symptomatic and overt hepatic injury.

PTU-induced symptomatic hepatic injury is not rare and usually develops within the first few months of PTU administration. Its clinical course is relatively benign. However, it may be difficult to predict its development, so all patients should be monitored for liver function test during the administration in early stage.