Warfarin-induced purple toe syndrome successfully treated with apixaban

Cholesterol Crystal Embolism Induced by Direct Factor Xa Inhibitor: A First Case Report

An 80-year-old man presented at our hospital with renal failure. He had been treated with edoxaban, an oral direct factor Xa inhibitor, for deep vein thrombosis for 10 months prior to admission. Although the pulses in his bilateral pedal arteries were palpable, cyanosis was present in the bilateral toes. Laboratory data indicated azotemia and eosinophilia. A skin biopsy confirmed a diagnosis of cholesterol crystal embolism (CCE). Because no invasive vascular procedure was performed, we assumed that CCE was related to edoxaban. To the best of our knowledge, this is the first case report suggesting CCE induced by an Xa inhibitor.

Adverse Drug Reactions and Cutaneous Manifestations Associated With Anticoagulation

Anticoagulants are amongst the most commonly prescribed medications worldwide. Although rare, localised and systemic drug reactions have been reported with anticoagulants that can lead to significant morbidity and mortality. Some of the first signs of drug reactions to anticoagulants are cutaneous changes that, when recognised early, can prevent significant complications. Dermatologists should be aware of these changes to make an early and accurate diagnosis. This is particularly important in instances of skin-induced necrosis caused by systemic toxicity to anticoagulants. This review discusses adverse drug reactions to the traditional anticoagulants, warfarin and heparin, and the newer direct oral anticoagulants (DOACs) such as the thrombin inhibitor, dabigatran, and the factor Xa inhibitors, rivaroxaban, apixaban, and edoxaban. In particular, this review provides dermatologists with a framework for early diagnosis and management of patients with drug reactions to anticoagulants and alerts them to potential bleeding complications associated with minor procedures.

Correlation between Rs2108622 Locus of CYP4F2 Gene Single Nucleotide Polymorphism and Warfarin Dosage in Iranian Cardiovascular Patients

Many cardiovascular diseases may require lifelong anticoagulation therapy. Warfarin is the most prescribed medication in this regard with serious side effects in some patients. Several single nucleotide polymorphisms (SNPs) affecting cytochrome P450 system can impact on warfarin metabolism and dosing. 230 cardiovascular patients have participated in the study. The INR levels were 1.5 to 3.5 with a mean range of 2.8. The subjects were divided into two case and control groups. The rs2108622 SNP of the CYP4F2 gene and its effect on warfarin dose requirements in these patients was evaluated.The results of our study showed a correlation between age and warfarin dosage. The overall frequency of the CC and TT allele of rs2108622 was 53.1% and 18.6%. Daily average dose of warfarin in CC, CT and TT variants was 3.5 ± 1.6, 4.5 ± 2.1 and 5.3 ± 2.1 respectively. The daily warfarin dose in patients with CC allele was significantly lower than that for CT or TT. The patients with TT allele required a 1.8 mg/day higher dose of warfarin than that of CC.While there are many studies regarding relation of age and warfarin dose, however, there are contradictory results about pharmacogentic status and warfarin dose in different ethnics. Our study demonstrates that polymorphism in the CYP4F2 rs2108622 has a significant impact on the warfarin requirements in Iranian patients.