偏側閉塞腎尿中アミカシン移行濃度

Abstract

偏側閉塞腎盂内薬剤(アミカシン)移行濃度を測定した.対象患者は9名で, 原疾患は尿管結石8例, 手術による一側尿管結紮1例であった.全例, 硫酸アミカシン100 mg静注後6時間で手術的に閉塞腎盂内尿を全量採取し一部を検体とした.硫酸アミカシン100 mg静注後30, 60, 120, 240, 360分と血液を採取, 正常側は膀胱尿とし2時間ごとに採取し, それぞれ濃度を測定した.血中・尿中アミカシン濃度はAMES TDDキットを用いSubstrate-Labeled Fluorescent Immuno-Assay法で測定した.尿中濃度は測定範囲を超えるため緩衝液で10～15倍に希釈し測定した.1)血中濃度は30分で8.8±1.0 mcg/mlと最高濃度を示し, 以後漸減した.2)健側腎からの各2時間ごとの尿中濃度はそれぞれ155.9±45.4 mcg/ml, 98.8±35.6 mcg/ml, 83.3±33.8 mcg/mlで, 閉塞腎盂尿中濃度は6時間尿とし118.9±52.3 mcg/mlであった.3)尿中排泄量は健側腎からの各2時間尿でそれぞれ28.3±3.4 mg, 9.6±3.6 mg, 9.3±3.5 mgで, 閉塞腎盂内尿中排泄量は16.8±3.0 mgであった.4) 1回100 mgアミカシン投与は閉塞腎感染予防の目的には有効と考えるが, 感染発生時には少なくとも200 mgの投与が必要と考える

Urinary amikacin concentration was determined in 9 patients with severely unilateral ureteral obstruction. Serum levels were within the normal range. The average concentration of amikacin in the urine from obstructed urinary tract was 118.9 mcg/ml 6 hours after 100 mg amikacin iv infusion. Urine concentration from the normal kidney was 155.9 mcg/ml at the first 2 hours after intravenous infusion, 98.8 at the second 2 hours 83.3 at the third 2 hours. Urinary amikacin excretion from severely obstructed urinary tract was about one third of the total excretion from a normal system. In summary, the urinary level in severely obstructed urinary tract after iv infusion of 100 mg amikacin may be enough prophylactically. But at the onset of infection in severely obstructed urinary tract, the administration of at least 200 mg amikacin intravenously is required.