Details

Autor(en) / Beteiligte

• Konishi, H.
• Eguchi, Y.
• Fujii, M.
• Saotome, T.
• Sasaki, T.
• Takahashi, K.
• Sudo, M.
• Morii, H.
• Minouchi, T.
• Yamaji, A.

Titel

Unusual hypersensitivity to warfarin in a critically ill patient

Ist Teil von

• Journal of clinical pharmacy and therapeutics, 2004-10, Vol.29 (5), p.485-490

Ort / Verlag

Oxford, UK: Blackwell Science Ltd

Erscheinungsjahr

2004

Link zum Volltext

Quelle

Wiley Online Library Journals【Remote access available】

Beschreibungen/Notizen

• Summary A patient was admitted to the intensive care unit because of respiratory failure, and warfarin therapy was started at 2 mg/day for the treatment of pulmonary embolism, together with other medications. Despite the low dosage of warfarin, international normalized ratio (INR) was markedly elevated from 1·15 to 11·28 for only 4 days, and bleeding symptoms concurrently developed. Vitamin K2 was infused along with discontinuation of warfarin. One day later, the INR was found to have decreased, and bleeding was also improved. An objective causality assessment indicated a probable relationship between clotting abnormality and warfarin administration, although the degree of elevation of the INR was unusual in the light of the daily warfarin dose and duration of its exposure. Based on the clinical status of the patient, it was suspected that several conditions contributed to the abnormal hypersensitivity to warfarin. Contributory factors probably included pharmacokinetic interactions with co‐administrated drugs, vitamin K deficiency caused by decreased dietary intake, reduced gut bacterial production, impaired intestinal absorption and hepatic synthetic capacity, and increased consumption of clotting factors. In view of our experience in the present case, it should be stressed that close monitoring of coagulation capacity is necessary in critically ill patients in order to avoid fatal haemorrhage after initiating warfarin therapy regardless of the dosage.