King Faisal University, Alahsa, Saudi Arabia.
Boston Medical Center, Boston, MA, USA.
J Prim Care Community Health. 2023 Jan-Dec;14:21501319231197588. doi: 10.1177/21501319231197588.
A case of a patient receiving warfarin for pulmonary embolism (PE) concomitantly with rifampin for treatment of active pulmonary tuberculosis (PTB) is presented. A successful clinical intervention whereby the patient achieved therapeutic anticoagulation after switching to an alternative rifamycin antibacterial, rifabutin, is described.
The drug-drug interaction between warfarin and rifampin is well known and documented. However, to our knowledge, no case reports of the interaction between warfarin and rifabutin have been published, and literature describing this interaction is lacking. We describe the case of a 27-year-old African American female referred to a pharmacist-managed anticoagulation clinic for treatment of PE with warfarin. The patient was also being treated for active tuberculosis with rifampin, isoniazid, pyrazinamide, and ethambutol. Warfarin was initiated and over the course of 1 month was continuously increased to a total weekly dose (TWD) of 140 mg without ever achieving the target international normalized ratio (INR) of 2 to 3. In an attempt to reach the target INR, rifampin was switched to rifabutin to minimize the drug-drug interaction with warfarin. Six days after this switch, the target INR was achieved with a lower warfarin TWD of 115 mg. Rifabutin interacts with warfarin to a lesser degree than rifampin and may be considered as an alternative in patients taking warfarin who require treatment with a rifamycin.
For patients in whom therapeutic anticoagulation with warfarin has been difficult, the use of rifabutin may be considered in place of rifampin when the concomitant use of a rifamycin is required.
介绍 1 例同时接受华法林治疗肺栓塞（PE）和利福平治疗活动性肺结核（PTB）的患者。描述了 1 例成功的临床干预措施，即在改用另一种利福霉素类抗菌药物利福布汀后，患者达到了治疗性抗凝效果。
华法林和利福平之间的药物相互作用是众所周知且有文献记载的。然而，据我们所知，尚未有华法林和利福布汀相互作用的病例报告发表，并且缺乏描述这种相互作用的文献。我们描述了 1 例 27 岁的非裔美国女性患者，因 PE 接受华法林治疗而被转至药师管理的抗凝门诊。该患者还同时接受利福平、异烟肼、吡嗪酰胺和乙胺丁醇治疗活动性肺结核。华法林开始治疗，在 1 个月的时间内持续增加剂量，总每周剂量（TWD）增至 140mg，但从未达到目标国际标准化比值（INR）2-3。为了达到目标 INR，将利福平换为利福布汀，以最大程度减少与华法林的药物相互作用。换用利福布汀 6 天后，达到了目标 INR，华法林 TWD 降至 115mg。利福布汀与华法林的相互作用程度较轻，因此在需要使用利福霉素类药物的同时需要服用华法林的患者中，可考虑使用利福布汀替代利福平。
对于那些难以用华法林进行治疗性抗凝的患者，如果需要同时使用利福霉素类药物，可考虑使用利福布汀替代利福平。
