Endocrine Abstracts

Introduction: The use of mitotane as ACC therapy is associated with multiple adverse effects including hypercholesterolemia due to increased levels of LDL cholesterol. There are no reported cases of severe hypertriglyceridemia (HTG).

Clinical case: A 59-year-old male with a personal history of dyslipidemia phenotype IV and pulmonary emphysema, former smoker and drinker was diagnosed with non-functioning left-sided ACC. Left adrenalectomy + left nephrectomy and subsequently right adrenalectomy and atypical segmentectomy of the upper right lung lobe due to the presence of metastases was performed. One month later, low-dose (2 g/day) mitotane therapy was initiated in combination with hydrocortisone and oral fludrocortisone replacement therapy. In the first post-mitotane control, triglycerides (TG) level which previously was 325 mg/dl increased to 953 mg/dl, coinciding with serum mitotane of 13.8 mg/l. Other factors that could increase it were overruled. Fenofibrate 145 mg/day was prescribed but in the following control TG were 880 mg/dl with serum mitotane of 14.3 mg/l. The dose of mitotane was then reduced to 1 g/day, its level dropped to 10.5 mg/l and TG were 939 mg/dl. Consequently ezetimibe 10 mg/day was added to the therapy and the mitotane dose was increased to 1.5 g/day and subsequently to 2 g/day because the level was very low and a 4.5 cm unresectable metastatic adenopathy that received radiotherapy appeared in the mediastinum. Coinciding with a mitotane level of 33.8 mg/l, the patient presented severe asthenia attributable to mitotane toxicity and TG of 1,528 mg/dl, without data of pancreatitis, what required a drastic decrease in the dose of drug. In the last review, the mitotane level was 6.7 mg/l, TG were 344 mg/dl, the symptoms disappeared and the mitotane dose was again raised while those of fenofibrate, ezetimibe, hydrocortisone and fludrocortisone remained the same.

Discussion: The presence and type of hyperlipemia prior to therapy is likely to affect the adverse effects of mitotane on lipids and in this patient, TG levels have varied according to mitotane doses and levels despite lipid-lowering therapy. On the other hand, dyslipidemia may induce an overestimation of plasma mitotane measurements, so it is necessary to closely monitor the lipid profile in all patients treated with this drug.