| 特集名 | 腎性貧血をもう一度考える | |
|---|---|---|
| 題名 | ［腎性貧血治療薬］葉酸，ビタミンB12，ビタミンC | |
| 発刊年月 | 2003年 04月 | |
| 著者 | 中村 享道 | 熊本市立熊本市民病院腎臓内科 |
| 著者 | 平山 英雄 | 平山泌尿器科医院 |
| 【 要旨 】 | 透析患者は葉酸，ビタミンB12の機能的欠乏状態にあり，遺伝子組み換えヒトエリスロポエチン（rHuEPO）抵抗性貧血と平均赤血球容積の著明な増大がみられる場合には，これらの欠乏を疑う．葉酸投与による悪性貧血の神経症状の悪化はまれであるが，抗痙攣薬服用患者への投与で痙攣が誘発されることがある．亜鉛吸収障害も報告されている．ビタミンB12過剰投与による副作用の報告はない． 感染症，炎症性疾患，アルミニウム中毒，副甲状腺機能亢進症などがなく，rHuEPO抵抗性貧血で機能的鉄欠乏状態にある患者にはビタミンC投与を考慮する．ビタミンCの連日大量投与で心血管系合併症の原因となる高シュウ酸血症が生じるので，連日投与時は150mg未満の投与量が安全である． |
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| Theme | Erythropoietin Up-To-Date | |
|---|---|---|
| Title | Treatment of epoetin-resistant anemia: folic acid, vitamin B12, ascorbic acid | |
| Author | Takamichi Nakamura | Division of Nephrology, Kumamoto City Hospital |
| Author | Hideo Hirayama | Hirayama Urology Clinic |
| [ Summary ] | Hemodialysis (HD) patients who developepoetin-resistant megaloblastic anemia and a dramatic rise in MCV, should be screened for folic acid and vitamin B12 (B12) deficiencies, since functional deficiencies of folic acid and B12 exist in HD patients without supplementation. Oral administration of folic acid (5mg twice daily) or treatment with a single dose, consisting of 1mg of B12, or a monthly dose of 1mg of B12 helps patients with epoetin-resistant megaloblastic anemia. Folic acid supplementation may, in rare cases, induce subacute combined degeneration of the spinal cord in patients with pernicious anemia. Folic acid supplementation has been reported to reverse the effectiveness of anticonvulsant medications in high doses and to interfare with the intestinal absorption of Zn. There are no reports describing adverse effects of supplementation of B12 in high doses in HD patients. Ascorbic acid supplementation corrects epoetin-resistant anemia in HD patients with iron overloads. Administration of ascorbic acid does not improve epoetin-resistant anemia secondary to infectious diseases, chronic inflammatory diseases, aluminum intoxication, or hyperparathyroidism. Intravenous administration of 500mg of ascorbic acid after HD therapy, for 3 months, improves epoetin-resistant anemia in patients with iron overloads. Ascorbic acid supplementation of 0.5 to 1.0g/day has been reported to increase plasma oxalate concentrations in HD patients. Since hyperoxalemia may contribute to vascular disease in HD patients, less than 150mg of ascorbic acid is recommended when it is administrated daily. |
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