早期血中トラフを達成し得た潰瘍性大腸炎の2例

抄録

Tacrolimus, a calcineurin inhibitor, has come to be well-known as effective therapy for steroid-refractory and steroid-dependent ulcerative colitis (UC) . It is necessary to achieve and maintain a trough level of tacrolimus in the blood of 10─15 ng/ml for effective induction of remission. We encountered 2 UC cases in which such target trough levels were rapidly achieved. Case 1 was a 48-year-old man with ulcerative colitis in whom remission could not be achieved in spite of mesalazinesteroid and adsorptive granulocyte and monocyte apheresis treatments. We started to administer 3 mg of tacrolimus daily and adjusted the daily dosage by checking the trough levels daily. The target trough level could be achieved by four days later after the start of treatment, and was effective to induce remission. Case 2 was a 38-year-old man with chronic continuous-type UC. He was under treatment with mesalazine, a steroid and azathioprine, however, his symptoms continued to worsen. We started treatment with 6 mg of tacrolimus daily, and the target trough level was achieved the very next day, with prompt induction of remission. Oral tacrolimus was discontinued three months later and oral azathioprine was used to maintain the remission in both patients, neither of whom showed any recurrence. The initial dose of tacrolimus for UC is usually 0.05 mg/kg/day, and the dose must be adjusted based on the trough levels. We have reported herein that an initial high dose of tacrolimus and daily measurement of the trough levels are effective for achieving the desired trough levels and prompt induction of remission.