Mayall B, Poggi G, Parkin J D
Repatriation General Hospital, Heidelberg, VIC.
Med J Aust. 1991 Oct 7;155(7):480-4. doi: 10.5694/j.1326-5377.1991.tb93847.x.
To review experience with neutropenia related to low-dose methotrexate therapy in patients with psoriasis and rheumatoid arthritis.
Retrospective review of medical records.
A 509-bed Melbourne teaching hospital.
Five patients admitted in 1987 and 1988, with neutrophil counts of less than 1 x 10(9)/L, given low doses of methotrexate for psoriasis or rheumatoid arthritis.
Death, or length of hospital admission.
Four patients were women, and one a man; three had been treated for psoriasis, and two for rheumatoid arthritis. Ages ranged from 56 to 91 years. The eldest patients, aged 77, 81 and 91 years, died. The other two were discharged after 43 and 48 days. Prior to or shortly after admission, four patients were treated with penicillin antibiotics which may have interfered with methotrexate excretion.
Methotrexate clearances (related to creatinine clearance rates and presumably low) were probably reduced sufficiently by concomitant therapy to result in neutropenia. Practitioners using methotrexate should be aware of drug interactions resulting in delayed methotrexate excretion. Blood counts should be monitored after changes in therapy, especially in patients with impaired renal function, such as the elderly.
回顾银屑病和类风湿关节炎患者中与低剂量甲氨蝶呤治疗相关的中性粒细胞减少症的经验。
对病历进行回顾性研究。
一家拥有509张床位的墨尔本教学医院。
1987年和1988年收治的5例患者，中性粒细胞计数低于1×10⁹/L，接受低剂量甲氨蝶呤治疗银屑病或类风湿关节炎。
死亡或住院时间。
4例为女性，1例为男性；3例接受银屑病治疗，2例接受类风湿关节炎治疗。年龄在56至91岁之间。年龄最大的3例患者，分别为77岁、81岁和91岁，死亡。另外2例分别在43天和48天后出院。在入院前或入院后不久，4例患者接受了青霉素类抗生素治疗，这可能干扰了甲氨蝶呤的排泄。
甲氨蝶呤清除率（与肌酐清除率相关且可能较低）可能因联合治疗而充分降低，从而导致中性粒细胞减少。使用甲氨蝶呤的医生应意识到药物相互作用会导致甲氨蝶呤排泄延迟。治疗方案改变后应监测血细胞计数，尤其是肾功能受损的患者，如老年人。
