Pharmaceutical care of INR level on a pulmonary embolism patient using warfarin

CHEN Yuan-na; CHEN Meng-jia; MA Wei-cheng; DU Zhen-nan

Abstract：A 67-year-old female patient was transferred to our hospital for the treatment of acute pulmonary embolism after 3 days of anticoagulant treatment in other hospital. The patient was given enoxaparin (5100 IU) for anticoagulant therapy after admission, and then 2.5 mg warfarin combined with enoxaparin for anticoagulation were used on the third day. The international standardization ratio (INR) of the patient was only 1.26 on the 11th day. Although with an increase of warfarin doses to 3.75 mg, the INR was still only 1.31 on the 15th day. With a comprehensive consideration of the medical history, dietary custom, drug interaction and other factors of the patient, the clinical pharmacist considered that the Chinese patent medicine of Shenqi Fuzheng might make the warfarin less effective, but not excluding a warfarin resistance in this patient. After communication with the physician, the clinical pharmacist suggested to stop using Shenqi Fuzheng, increase the dose of warfarin, and test the genotype associated with warfarin, and those suggestions obtained the approval of the doctor. By following the advice, the patient's INR increased to 1.97 on the 17th day, and kept increasing to 2.47 on the 19th day. Because the patient was discharged from hospital on the 20th day, the dose of warfarin was adjusted to 3.75 mg. After a month, the clinical pharmacist was informed that the patient's INR was maintained between 2.0 and 3.0 during the time of taking warfarin, without adverse effects such as hemorrhage by telephone follow-up.