Takase Tomoki, Ikesue Hiroaki, Tohi Makiko, Ueta Hiroshi, Mima Hiroyuki, Koyama Tadaaki, Hashida Tohru
1Department of Pharmacy, Kobe City Medical Center General Hospital, 2-2-1, Minatojima Minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 Japan.
2Department of Anesthesiology and Critical Care, Kobe City Medical Center General Hospital, 2-2-1, Minatojima Minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 Japan.
J Pharm Health Care Sci. 2018 May 30;4:13. doi: 10.1186/s40780-018-0110-6. eCollection 2018.
Amiodarone and warfarin are sometimes administered immediately after cardiac surgery. Although the interaction between long-term oral amiodarone and warfarin has been reported, the interaction between warfarin and short-term intravenous amiodarone has not been reported. In this study, we investigated the effect of short-term intravenous amiodarone on the anticoagulant effect of warfarin in patients who underwent cardiac surgery.
We retrospectively reviewed the medical records of 11 patients who received oral warfarin before and after cardiac surgery, and loading doses of 125-150 mg or a 750 mg continuous infusion of amiodarone, or both in the intensive care unit (ICU) within 5 days after the surgery between July 2011 and January 2017. The prothrombin time-international normalized ratio (PT-INR)/daily warfarin dose (PT-INR/dose) was used as an indicator of anticoagulant effect. The values before surgery were considered as the baseline.
The PT-INR and PT-INR/dose values were elevated in 7 and 10 patients, respectively, after amiodarone administration. The mean PT-INR values were not significantly different before and after amiodarone administration (2.13 ± 0.58 vs 2.29 ± 0.50, respectively, = 0.643). In contrast, the mean PT-INR/dose values were significantly elevated after the administration of amiodarone (0.93 ± 0.46 vs 1.54 ± 0.63, respectively, = 0.002).
Short-term intravenous amiodarone enhanced the anticoagulant effect of warfarin in patients admitted to the ICU after cardiac surgery. We suggest that the dose of warfarin should be carefully adjusted for a few days after cardiac surgery if intravenous amiodarone is coadministered.
胺碘酮和华法林有时会在心脏手术后立即使用。虽然长期口服胺碘酮与华法林之间的相互作用已有报道，但华法林与短期静脉注射胺碘酮之间的相互作用尚未见报道。在本研究中，我们调查了短期静脉注射胺碘酮对心脏手术后患者华法林抗凝效果的影响。
我们回顾性分析了2011年7月至2017年1月期间11例在心脏手术前后接受口服华法林治疗的患者的病历，这些患者在术后5天内在重症监护病房（ICU）接受了125 - 150mg的负荷剂量或750mg的胺碘酮持续输注，或两者兼用。采用凝血酶原时间 - 国际标准化比值（PT-INR）/每日华法林剂量（PT-INR/剂量）作为抗凝效果指标。手术前的值作为基线。
胺碘酮给药后，分别有7例和10例患者的PT-INR和PT-INR/剂量值升高。胺碘酮给药前后的平均PT-INR值无显著差异（分别为2.13±0.58和2.29±0.50，P = 0.643）。相比之下，胺碘酮给药后平均PT-INR/剂量值显著升高（分别为0.93±0.46和1.54±0.63，P = 0.002）。
短期静脉注射胺碘酮增强了心脏手术后入住ICU患者华法林的抗凝效果。我们建议，如果同时使用静脉注射胺碘酮，心脏手术后几天应仔细调整华法林剂量。
