Gulløv A L, Koefoed B G, Petersen P
Københavns Praktiserende Laegers Laboratorium.
Ugeskr Laeger. 1996 Sep 9;158(37):5174-5.
A case of presumed interaction between warfarin and nalidixic acid is reported in an 84 year-old female in whom INR rose from 1.9 to 9.6 after start of treatment with nalidixic acid. The interaction may be caused by several factors: 1) Nalidixic acid may displace warfarin from plasma proteins and thereby increase the anticoagulant effect. 2) The fluoroquinolone drug enoxacin reduces the hepatic clearance of the R-stereomere of warfarin but without prolongation of the prothrombin time ratio. 3) Fluoroquinolones may affect the vitamin-K producing bacteria in the gut and thereby influence the vitamin-K: warfarin ratio in plasma. Only some patients develop hypoprothrombinaemia during concomitant therapy with warfarin and quinolone antimicrobials. It is hypothesized that the interaction may partly be related to age, sex or concomitant disease. Frequent control of INR in patients treated with both warfarin and quinolone antimicrobials is recommended.
据报道，一名84岁女性疑似华法林与萘啶酸发生相互作用，在开始使用萘啶酸治疗后，其国际标准化比值（INR）从1.9升至9.6。这种相互作用可能由多种因素引起：1）萘啶酸可能将华法林从血浆蛋白中置换出来，从而增强抗凝作用。2）氟喹诺酮类药物依诺沙星可降低华法林R-异构体的肝脏清除率，但不会延长凝血酶原时间比值。3）氟喹诺酮类药物可能影响肠道中产生维生素K的细菌，从而影响血浆中维生素K与华法林的比例。只有部分患者在华法林与喹诺酮类抗菌药物联合治疗期间出现低凝血酶原血症。据推测，这种相互作用可能部分与年龄、性别或伴随疾病有关。建议同时使用华法林和喹诺酮类抗菌药物治疗的患者定期监测INR。
