[A case of partial Addison's disease activated with the administration of rifampicin (RFP)].

The patient was a 76 year-old female with tuberculous tendonitis, treated with anti-tuberculous drugs including rifampicin (RFP). About two weeks after the start of RFP, she noticed general malaise and started vomiting, and the laboratory data showed severe hyponatremia. Because of mild liver dysfunction, RFP was discontinued and her symptoms gradually improved. Abdominal X-ray and CT showed swellings and calcifications of adrenal glands bilaterally. Serum ACTH level was high and cortisole, 17-OHCS, and 17-KS levels were normal. Her response to rapid ACTH stimulation was blunted significantly. After another trial of RFP, she started to vomit and complain general malaise again. We diagnosed her as partial Addison's disease and administered hydrocortisone with RFP. After this treatment her improvement was rapid. It has been known that RFP causes induction of enzymes in hepatic microsomes which increase the catabolism of glucocorticoids. To avoid the risk of adrenal insufficiency, patients with insufficient adrenal hormone reserve should receive compensatory hydrocortisone while they are taking RFP.