Nonhemorrhagic joint disorders and vitamin K antagonists: an under-recognized adverse drug reaction?

Isolated arthralgia, without hemorrhagic side effect, exists and is considered as a very rare adverse drug reaction according to vitamin K antagonists' (VKAs) summary of product characteristics. Up to now, there are no literature reports of isolated, nonhemorrhagic joint complications in patients receiving VKAs. Hence, the objective of this study was to describe cases of VKA-related nonhemorrhagic joint disorders (fluindione, warfarin, and acenocoumarol) reported in the French Pharmacovigilance Database (FPVD). Sixty-one reports (male : female ratio, 1.18; median [interquartile range (IQR)] age: 60 [49-72]) were found. Fluindione, warfarin, and acenocoumarol were respectively suspected in 42, 12, and 7 cases. Arthralgia was reported in 47 cases (77%), arthritis in nine cases (15%), capsulitis in three cases (5%), and bursitis in two cases (3%). Although the joint symptoms mainly concerned the lower limbs, all types of joints were affected. Arthralgia was associated with myalgia in 14 cases and with tendinitis in three cases. The median (IQR) time interval between VKA introduction and arthralgia onset was 26 (10-98) days (range: 1-6935). VKA was withdrawn in 44 cases, and a decrease in the intensity of joint symptoms was observed in 30 cases. In three cases, reintroduction of the same VKA led to the recurrence of symptoms. In view of the large prescription of this drug class worldwide, patients and clinicians (and especially primary care physicians and geriatricians) should be aware of this possible adverse drug reaction when confronted with joint disorders in patients of all ages taking VKAs.

DRESS syndrome with thrombotic microangiopathy revealing a Noonan syndrome: Case report.

RATIONALE: The life-threatening drug rash with eosinophilia and systemic symptoms (DRESS) syndrome occurs most commonly after exposure to drugs, clinical features mimic those found with other serious systemic disorders. It is rarely associated with thrombotic microangiopathy. PATIENT CONCERNS: We describe the unique case of a 44-year-old man who simultaneously experienced DRESS syndrome with thrombotic microangiopathy (TMA) after a 5 days treatment with fluindione. DIAGNOSES: Clinical evaluation leads to the discovery of an underlying lymphangiomatosis, due to a Noonan syndrome. INTERVETIONS: The anticoagulant was withdrawn, and corticosteroids (1 mg/kg/day) and acenocoumarol were started. OUTCOMES: Clinical improvement ensued. At follow-up the patient is well. LESSONS: The association of DRESS with TMA is a rare condition; we believe that the presence of the underlying Noonan syndrome could have been the trigger. Moreover, we speculate about the potential interrelations between these entities.

Unexpected Problems of Antithrombotic Therapy with An Unusual Side Effect of Vitamin K Antagonists after Mitral Valve Replacement.

Except for bleeding complications, vitamin K antagonists (VKAs) are known to have few undesirable side effects. Herein is presented the case of a 45-year-old woman in whom liver damage was induced by fluindione and warfarin after mitral valve replacement. Hepatotoxicity is a rare complication of VKAs, both in the French National and Drug Safety registry and the medical literature. A diagnosis of VKA-induced drug damage was confirmed by the absence of other etiologies, the chronological sequence, recurrence after re-exposure to VKA, and rapid improvements after discontinuation of the drug. Despite possible cross-reactions between VKAs, the re-introduction of acenocoumarol was successfully achieved, with no recurrence of biological disturbances.

[Spontaneous hematoma of right angle of the transverse mesocolon: exceptional complication of anticoagulant therapy with vitamin K]. / Hématome spontané du méso de l'angle colique droit et du colon transverse compliquant un traitement par anti vitamine K: à propos d'un cas et revue de la littérature.

Spontaneous hematoma of transverse mesocolon is a rare complication of anticoagulant treatment with vitamin K. We report the case of spontaneous hematoma of right angle of the transverse mesocolon associated with a hemoperitoneum in a 32-year-old patient treated by fluindione for pulmonary embolism. The diagnosis must be made urgently. The abdominal ultrasound and the scanning confirm the diagnosis. It is important to note that surgery is indicated only in the case of complications such as the risk of rupture of the hematoma.

[Agranulocytosis related to fluindione: A case report]. / Agranulocytose à la fluindione: à propos d'un cas.

INTRODUCTION: While in most countries warfarin is the preferred anti-vitamin K, fluindione, a molecule with a prolonged half-life remains largely prescribed in France. Some of its side effects, including immuno-allergic complications, remain poorly understood. CASE REPORT: A 77-year-old woman presented with a febrile severe neutropenia of immunoallergic mechanism with a favourable outcome associated with fluindione, introduced 25 days earlier for the treatment of atrial fibrillation. CONCLUSION: This rare side effect is a reminder of the importance of biological monitoring in the first weeks following the introduction of fluindione and key diagnostic elements and therapeutic aspects of iatrogenic agranulocytosis.

Risk of bleeding and arterial thromboembolism in patients with non-valvular atrial fibrillation either maintained on a vitamin K antagonist or switched to a non-vitamin K-antagonist oral anticoagulant: a retrospective, matched-cohort study.

BACKGROUND: Patients with non-valvular atrial fibrillation who are receiving or have been previously exposed to a vitamin K antagonist could be switched to a non-vitamin K-antagonist oral anticoagulant (NOAC) but little information is available about the risk of bleeding and arterial thromboembolism after such a switch. We aimed to compare the risk of bleeding between individuals who switched and those who remained on a vitamin K antagonist (non-switchers) in real-world conditions. METHODS: We did a matched-cohort study with information from French health-care databases. We extracted data for adults (aged ≥18 years) with non-valvular atrial fibrillation who received their first prescription for a vitamin K antagonist (fluindione, warfarin, or acenocoumarol) between Jan 1, 2011, and Nov 30, 2012, and who were either switched to a NOAC (dabigatran or rivaroxaban) or maintained on the vitamin K antagonist. Each switcher was matched with up to two non-switchers on the basis of eight variables, including sex, age, and international normalised ratio number. The primary endpoint was incidence of bleeding (intracranial haemorrhage, gastrointestinal haemorrhage, or other) in switchers versus non-switchers, and switchers stratified by type of NOAC versus non-switchers, noted from databases of hospital admissions. Each patient was followed up to 1 year; the study closed on Oct 1, 2013. FINDINGS: Of 17,410 participants, 6705 switched to a NOAC (switchers) and 10,705 remained on vitamin K-antagonist therapy (non-switchers). Median age of participants was 75 years (IQR 67-82), 8339 (48%) were women, and the median duration of vitamin K-antagonist exposure before a switch was 8.1 months (IQR 3.9-14.0). After a median follow-up of 10.0 months (IQR 9.8-10.0), we noted no difference between groups for bleeding events (99 [1%] in switchers vs 193 [2%] in non-switchers, p=0.54). In adjusted multivariate analyses, the risk of bleeding in switchers was not different from that in non-switchers (hazard ratio [HR] 0.87; 95% CI 0.67-1.13, p=0.30). Additionally, no differences were noted when the risk of bleeding was compared between switchers from a vitamin K antagonist to dabigatran (HR 0.78, 95% CI 0.54-1.09, p=0.15), switchers from a vitamin K antagonist to rivaroxaban (HR 1.04, 95% CI 0.68-1.58, p=0.86), and non-switchers. INTERPRETATION: In this matched-cohort study, our findings suggest that patients with non-valvular atrial fibrillation who switch their oral anticoagulant treatment from a vitamin K antagonist to a non-vitamin K antagonist are not at increased risk of bleeding. Future studies with longer follow-up might be needed. FUNDING: None.

Vitamin K antagonists and cognitive impairment: results from a cross-sectional pilot study among geriatric patients.

BACKGROUND: Vitamin K is involved in brain physiology, suggesting that its deficiency induces cognitive decline. Our objective was to determine whether using vitamin K antagonists (VKAs) was associated with cognitive impairment among geriatric patients. METHODS: Two hundred sixty-seven older patients (mean, 83.4 ± 8.1 years; 56.9% female) were categorized according to cognitive impairment (ie, Mini-Mental State Examination ≤ 25). The regular use of VKAs was sought by questioning the patients, relatives, and family physicians. Age, gender, body mass index, comorbidity burden, mood and executive functioning, history of atrial fibrillation, ischemic stroke, intracranial hemorrhage and transient ischemic attack, use of other anticoagulants and antiplatelet medications, and severe renal failure were used as potential confounders. RESULTS: Compared with participants without cognitive impairment (n = 70), those with Mini-Mental State Examination ≤ 25 used more frequently VKAs (p = .038). The risk of cognitive impairment was 15% higher with VKAs, specifically with fluindione. Using VKAs was independently associated with cognitive impairment (fully adjusted odds ratio = 17.4 [95% CI: 1.4-224.2], p = .028). CONCLUSIONS: We found more frequent cognitive impairment associated with the use of VKAs, specifically fluindione, among geriatric patients.

Phenindione interference in enzymatic creatinine assay - A case report.

Enzymatic creatinine assays are considered superior to Jaffe assays due to greater analytical specificity. We report a case of phenindione interference with an enzymatic assay resulting in significant misclassification in a patient with chronic kidney disease (CKD). Analysis of creatinine values of a further 36 patients who were treated with phenindione showed significant negative interference of phenindione with the Roche enzymatic creatinine assay.

Probable interaction between an oral vitamin K antagonist and turmeric (Curcuma longa).

We report a probable interaction between a vitamin K antagonist, fluindione, and the herbal medicine turmeric that resulted in the elevation of the international normalized ratio (INR). The case presented here underlines the importance of considering potential exposure to herbal medications when assessing adverse effects.

Risk factors associated with a thrombotic or bleeding event in patients treated with vitamin K antagonists.

AIM: To identify, in a case-control study, the risk factors associated with a thrombotic or bleeding event in patients treated with vitamin K antagonists. MATERIALS AND METHODS: We performed a single-centre observational study during a three-month period where we consecutively included patients admitted to the emergency department of a secondary-level hospital and treated with vitamin K antagonists, regardless the reason for admission. Patients admitted for a thrombotic or bleeding event were included as cases and the other patients served as controls. Main thrombotic or bleeding risk factors during vitamin K antagonist therapy were a priori identified in literature and tested in conditional logistic regression. RESULTS: Two hundred and forty subjects were identified, 40 of which (17%) were admitted for a bleeding event, 19 (8%) for a thrombotic event and 181 (75%) for another reason. Over 85% of patients were treated with fluindione. No risk factor was significantly associated with bleeding or thrombotic event in patients treated with vitamin K antagonist. Patients presenting a thrombotic event were however more likely to have a chronic respiratory disease. CONCLUSIONS: In this study, no risk factor significantly associated with a bleeding or thrombotic event in patients treated with vitamin K antagonist were identified. The occurrence of these events supposes other risk factors, including potential genetic polymorphisms that should be considered in future studies.

Skin necrosis due to fluindione treatment: a rare but serious complication.

In the setting of protein C deficiency, skin necrosis, which occurs most often at the initial phase of oral anticoagulants therapy, is a rare side effect. Six cases have previously been reported in the literature. In this case report, we present a protein C deficient 42-year-old woman who was being treated for venous thrombosis. Five days after the initiation of oral anticoagulant treatment, she developed extensive skin necrosis on her left calf, followed by a painful leg ulcer. The pathogenesis underlying skin necrosis caused by anticoagulation therapy is still not clear. Despite only a few cases being reported in the literature, it is important to recognise this complication since adequate therapeutic approaches leading to a stable anticoagulation state may prevent it.

[Recurrent pyoderma gangrenosum-like ulcers induced by oral anticoagulants]. / Ulcérations récidivantes à type de pyoderma grangrenosum induites par les antivitamines K.

BACKGROUND: Other than the classic skin necrosis induced by oral anticoagulants (OAC) in patients with protein C and S deficiencies, other types of OAC induced-skin ulcers are little known. Herein, we describe an original case of recurrent pyoderma gangrenosum (PG)-like ulcers induced by OAC. PATIENTS AND METHODS: A 70-year-old female heart-transplant recipient presented deep, hyperalgesic and quickly-spreading necrotic ulceration of the right leg 6 weeks after starting oral anticoagulant therapy with fluindione. Histological analysis revealed dermal infiltrate containing polynuclear neutrophils, which accords with the histopathological diagnosis of leukocytoclastic vasculitis or PG. Infectious, autoimmune and thrombophilic causes were ruled out. Fluindione was withdrawn and the ulcer healed completely within a month. Six months later, right leg ulceration recurred two weeks after the patient resumed fluindione but healed within 1 month of discontinuation of the drug. An OAC from another chemical family (warfarin) was then introduced, with further recurrence of ulceration after 2 weeks of treatment. DISCUSSION: The chronology of events and the negativity of aetiological explorations allowed a diagnosis to be made of OAC-induced skin ulcer, a rare complication of which the pathophysiology is unclear. This is the first case of PG-like ulcers induced by OAC.

Maintenance of anticoagulant and antiplatelet agents for patients undergoing peribulbar anesthesia and vitreoretinal surgery.

PURPOSE: To establish the prevalence of anticoagulation (vitamin K antagonists) and antiplatelet agent therapy in patients undergoing vitreoretinal surgery and to compare the outcome of peribulbar anesthesia and vitreoretinal surgery between users and nonusers. METHODS: We conducted a retrospective case series study in one academic center. No changes in the treatment regimen were made before surgery. Patients were divided into 3 groups: G1, patients with no anticoagulant or antiplatelet therapy; G2, patients treated with anticoagulants; and G3, patients treated with aspirin, clopidogrel, or both. RESULTS: Two hundred and six eyes (206 patients) were included. G1, 144 eyes (69.9%) without any anticoagulant or antiplatelet therapy (69.9%); G2, 12 eyes (5.8%) with anticoagulants; and G3, 44 eyes (21.4%) with antiplatelet agents. Six patients (6 eyes) (2.9%) received both anticoagulant and antiplatelet agents. The incidence of overall and mild postoperative hemorrhagic complications was similar between groups, P = 0.075 and P = 0.127, respectively. However, potential sight-threatening hemorrhagic complications were more frequent in patients receiving antiplatelet agents, P < 0.003. CONCLUSION: Peribulbar anesthesia for vitreoretinal surgery can probably be performed safely in patients receiving anticoagulants. However, retinal surgeons should be aware that severe bleeding complications are more frequent in patients receiving antiplatelet therapy.