The incidence of anaphylaxis following intravenous phytonadione (vitamin K1): a 5-year retrospective review

Vitamin K: a potential missing link in critical illness-a scoping review

BACKGROUND

Vitamin K is essential for numerous physiological processes, including coagulation, bone metabolism, tissue calcification, and antioxidant activity. Deficiency, prevalent in critically ill ICU patients, impacts coagulation and increases the risk of bleeding and other complications. This review aims to elucidate the metabolism of vitamin K in the context of critical illness and identify a potential therapeutic approach.

METHODS

In December 2023, a scoping review was conducted using the PRISMA Extension for Scoping Reviews. Literature was searched in PubMed, Embase, and Cochrane databases without restrictions. Inclusion criteria were studies on adult ICU patients discussing vitamin K deficiency and/or supplementation.

RESULTS

A total of 1712 articles were screened, and 13 met the inclusion criteria. Vitamin K deficiency in ICU patients is linked to malnutrition, impaired absorption, antibiotic use, increased turnover, and genetic factors. Observational studies show higher PIVKA-II levels in ICU patients, indicating reduced vitamin K status. Risk factors include inadequate intake, disrupted absorption, and increased physiological demands. Supplementation studies suggest vitamin K can improve status but not normalize it completely. Vitamin K deficiency may correlate with prolonged ICU stays, mechanical ventilation, and increased mortality. Factors such as genetic polymorphisms and disrupted microbiomes also contribute to deficiency, underscoring the need for individualized nutritional strategies and further research on optimal supplementation dosages and administration routes.

CONCLUSIONS

Addressing vitamin K deficiency in ICU patients is crucial for mitigating risks associated with critical illness, yet optimal management strategies require further investigation.

IMPACT RESEARCH

To the best of our knowledge, this review is the first to address the prevalence and progression of vitamin K deficiency in critically ill patients. It guides clinicians in diagnosing and managing vitamin K deficiency in intensive care and suggests practical strategies for supplementing vitamin K in critically ill patients. This review provides a comprehensive overview of the existing literature, and serves as a valuable resource for clinicians, researchers, and policymakers in critical care medicine.

Effect of Phytonadione on Correction of Coagulopathy in Pediatric Patients With Septic Shock

OBJECTIVES

The purpose of this study was to evaluate phytonadione in children with septic shock with disseminated intravascular coagulopathy (DIC). The primary objective was to identify the number of patients with an international normalized ratio (INR), defined as ≤1.2, following phytonadione. Secondary objectives were to compare patients who achieved a normalized INR versus those with INR >1.2 and to determine factors associated with a normalized INR.

METHODS

A retrospective study of children <18 years of age receiving phytonadione from October 1, 2013, to August 31, 2020, with a diagnosis of septic shock, were included. Data collection included demographics, phytonadione regimen, INR values, Pediatric Index of Mortality 2 (PIM2) and Pediatric Risk of Mortality III (PRISM III) scores, fresh frozen plasma (FFP) and cryoprecipitate use. A logistic regression model and generalized linear model were used to explore factors associated with a normalized INR and evaluate phytonadione dosing.

RESULTS

Data for initial phytonadione course for 156 patients were evaluated. Sixty-six (42.3%) patients had a normalized INR. Most patients (n = 145; 92.9%) received ≤3 phytonadione doses, with the largest reduction in INR occurring after the second dose. In the logistic regression model, baseline INR, FFP, cryoprecipitate, vasopressors, PIM2, PRISM III, or cumulative phytonadione dose were not associated with achieving a normalized INR.

CONCLUSIONS

Less than half of patients achieved a normalized INR. The median cumulative dose of phytonadione and receipt of FFP or cryoprecipitate was not associated with an increased odds of a normalized INR. Future studies are needed to further explore phytonadione use in children with sepsis-induced coagulopathy.

Alternative Excipients for Protein Stabilization in Protein Therapeutics: Overcoming the Limitations of Polysorbates

Given their safety and efficiency in protecting protein integrity, polysorbates (PSs) have been the most widely used excipients for the stabilization of protein therapeutics for years. In recent decades, however, there have been numerous reports about visible or sub-visible particles in PS-containing biotherapeutic products, which is a major quality concern for parenteral drugs. Alternative excipients that are safe for parenteral administration, efficient in protecting different protein drugs against various stress conditions, effective in protein stabilization in high-concentrated liquid formulations, stable under the storage conditions for the duration of the product's shelf-life, and compatible with other formulation components and the primary packaging are highly sought after. The aim of this paper is to review potential alternative excipients from different families, including surfactants, carbohydrate- and amino acid-based excipients, synthetic amphiphilic polymers, and ionic liquids that enable protein stabilization. For each category, important characteristics such as the ability to stabilize proteins against thermal and mechanical stresses, current knowledge related to the safety profile for parenteral administration, potential interactions with other formulation components, and primary packaging are debated. Based on the provided information and the detailed discussion thereof, this paper may pave the way for the identification or development of efficient excipients for biotherapeutic protein stabilization.

Allergy testing for Cremophor in a patient with cervical cancer with infusion reactions to paclitaxel and docetaxel

A woman in her 30s with cervical cancer underwent postoperative chemotherapy and showed allergic reactions to multiple taxanes. As the patient had infusion reactions to both paclitaxel and docetaxel, a prick test with Cremophor was conducted. In the absence of an allergic reaction to etoposide, we determined that the patient was allergic to pure taxane compounds. Among infusion reactions caused by taxanes, Cremophor allergy is reported in 3% of cases. Therefore, a prick test with Cremophor performed on a taxane infusion reaction will be useful in diagnosing allergy. In addition, allergy due to docetaxel may be managed by adequate premedication and continuous intravenous chlorpheniramine administration.

The Role of Vitamin K in Cirrhosis: Do Pharmaco-K-Netics Matter?

Patients with advanced liver disease who are not taking vitamin K antagonists often have an elevated international normalized ratio, potentially due to vitamin K deficiency and the decreased synthesis of clotting factors by the liver. It is possible that vitamin K deficiency is due to dietary deficiency, impaired absorption in the small intestine, or both. This has led to the practice of the administration of phytonadione to limit the risks of bleeding in these patients. However, phytonadione is available in different formulations with varying pharmacokinetics and there is a paucity of data in the literature to guide optimal management. The routine use of phytonadione to correct INR in cirrhotic patients not taking warfarin should be avoided due to the lack of proven benefits. However, intravenous phytonadione may be considered in actively bleeding or critically ill patients with vitamin K deficiency. Oral formulation is unlikely to be absorbed in cirrhotic patients and should be avoided.

Methods to Correct Drug-Induced Coagulopathy in Bleeding Emergencies: A Comparative Review

OBJECTIVE

Anticoagulant and antiplatelet therapy have become increasingly popular. The goal of therapy is to prevent venous thromboembolism and platelet aggregation, respectively. Traditional anticoagulant and antiplatelet drugs are quickly being replaced with novel medications with more predictable pharmacokinetics. Unfortunately, these drugs carry the risk of uncontrolled hemorrhage because of drug-induced coagulopathy. Uncontrolled hemorrhage continues to be a major cause of preventable death: hemorrhage accounts for approximately 30% of trauma-related deaths, second to brain injury. Controlling hemorrhage while dealing with comorbidities remains a challenge to clinicians. There are many gaps in care and knowledge that contribute to the struggle of treating this patient population.

METHODS

This literature review is focused on the most effective ways to achieve hemostasis in a patient with drug-induced coagulopathy. The antiplatelet therapies aspirin, clopidogrel, ticlopidine, pasugrel, and ticagrelor are analyzed. Anticoagulant therapies are also reviewed, including warfarin, rivaroxaban, apixaban, edoxaban, and dabigatran. In addition, viscoelastic testing and platelet function assays are reviewed for their ability to monitor drug effectiveness and to accurately depict the patient's ability to clot. This review focuses on articles from the past 10 years. However, there are limitations to the 10-year restriction, including no new research posted within the 10-year timeline on particular subjects. The most recent article was then used where current literature did not exist (within 10 years).

RESULTS

Traditional anticoagulants have unpredictable pharmacokinetics and can be difficult to correct in bleeding emergencies. Vitamin K has been proven to reliably and effectively reverse the effect of vitamin K antagonists (VKAs) while having a lower anaphylactoid risk than frozen plasma. Prothrombin complex concentrates should be used when there is risk of loss of life or limb. Frozen plasma is not recommended as a first-line treatment for the reversal of VKAs. Novel anticoagulants have specific reversal agents such as idarucizumab for dabigatran and andexxa alfa for factor Xa (FXa) inhibitors. Although reliable, these drugs carry a large price tag. As with traditional anticoagulants, cheaper alternative therapies are available such as prothrombin complex concentrates. Finally, static coagulation testing works well for routine therapeutic drug monitoring but may not be appropriate during bleeding emergencies. Viscoelastic testing such as thromboelastography and rotational thromboelastometry depict in vivo hemostatic properties more accurately than static coagulation assays. Adding viscoelastic testing into resuscitation protocols may guide blood product usage more efficiently.

CONCLUSION

This review is intended to be used as a guide. The topics covered in this review should be used as a reference for treating the conditions described. This review article also covers laboratory testing and is meant as a guide for physicians on best practices. These findings illustrate recommended testing and reversal techniques based off evidence-based medicine and literature.

Effects of Obesity on Warfarin Reversal With Vitamin K

Phytonadione (vitamin K1, VK) is fat soluble and may be sequestered by adipose tissue, thus potentially altering drug distribution in obese patients requiring warfarin reversal. This single-center retrospective cohort study aimed to determine the effects of obesity (defined as body mass index [BMI] ≥ 30 kg/m²) on warfarin reversal following administration of VK in adult patients. The primary outcome was complete or partial warfarin reversal (defined as an international normalized ratio [INR] ≤ 2.0) within 72 hours post-VK administration. Of 688 identified patients, 215 were included in primary INR analysis. Mean BMIs for obese (n = 84) and nonobese (n = 131) patients were 37.3 and 24.3 kg/m² ( P < .001), and mean baseline INRs were 4.73 and 4.42 ( P = .534), respectively. Within 72 hours post-VK administration, 70% and 69% of the obese and nonobese groups, respectively, achieved complete or partial warfarin reversal ( P = .904). Multiple logistic regression determined baseline INR and concomitant fresh frozen plasma administration to be factors influencing warfarin reversal. These findings do not suggest obesity is significantly associated with a decreased likelihood of warfarin reversal within 72 hours post-VK administration.

Bad weed: synthetic cannabinoid–associated coagulopathy

Recent multistate outbreaks of coagulopathy caused by brodifacoum-tainted synthetic cannabinoids or “fake weed” highlight the public health impact of long-acting anticoagulant rodenticides (LAARs). Patients presenting with this syndrome have had recent exposure to synthetic cannabinoids, evidence of isolated vitamin K antagonism with or without bleeding, and detectable levels of brodifacoum and other LAARs in circulation. This article will provide information on synthetic cannabinoids, LAARs, and coagulopathic manifestations arising from use of adulterated synthetic cannabinoids and their management.

Antithrombotic Reversal Agents

The actively bleeding anticoagulated patient presenting to the emergency department requires rapid evaluation and treatment, which is made increasingly complicated by the ever-evolving antithrombotic treatment options used in medicine. Even with excellent supportive care, the timeliness with which reversal decisions need to be made continues to demand of the emergency practitioner a familiarity with the properties and general characteristics of a variety of antithrombotic agents. Reversal options vary and may include vitamin K, FFP, PCC, rFVIIa, platelets, and desmopressin, among others.

Hemostasis in Intracranial Hemorrhage

Spontaneous non-traumatic intracerebral hemorrhage (ICH) is associated with high morbidity and mortality throughout the world with no proven effective treatment. Majority of hematoma expansion occur within 4 h after symptom onset and is associated with early deterioration and poor clinical outcome. There is a vital role of ultra-early hemostatic therapy in ICH to limit hematoma expansion. Patients at risk for hematoma expansion are with underlying hemostatic abnormalities. Treatment strategy should include appropriate intervention based on the history of use of antithrombotic use or an underlying coagulopathy in patients with ICH. For antiplatelet-associated ICH, recommendation is to discontinue antiplatelet agent and transfuse platelets to those who will undergo neurosurgical procedure with moderate quality of evidence. For vitamin K antagonist-associated ICH, administration of 3-factor or 4-factor prothrombin complex concentrates (PCCs) rather than fresh frozen plasma to patients with INR >1.4 is strongly recommended. For patients with novel oral anticoagulant-associated ICH, administering activated charcoal to those who present within 2 h of ingestion is recommended. Idarucizumab, a humanized monoclonal antibody fragment against dabigatran (direct thrombin inhibitor) is approved by FDA for emergency situations. Administer activated PCC (50 U/kg) or 4-factor PCC (50 U/kg) to patients with ICH associated with direct thrombin inhibitors (DTI) if idarucizumab is not available or if the hemorrhage is associated with a DTI other than dabigatran. For factor Xa inhibitor-associated ICH, administration of 4-factor PCC or aPCC is preferred over recombinant FVIIa because of the lower risk of adverse thrombotic events.

Management of neurologic complications of coagulopathies

Coagulopathy is common in intensive care units (ICUs). Many physiologic derangements lead to dysfunctional hemostasis; these may be either congenital or acquired. The most devastating outcome of coagulopathy in the critically ill is major bleeding, defined by transfusion requirement, hemodynamic instability, or intracranial hemorrhage. ICU coagulopathy often poses complex management dilemmas, as bleeding risk must be tempered with thrombotic potential. Coagulopathy associated with intracranial hemorrhage bears directly on prognosis and outcome. There is a paucity of high-quality evidence for the management of coagulopathies in neurocritical care; however, data derived from studies of patients with intraparenchymal hemorrhage may inform treatment decisions. Coagulopathy is often broadly defined as any derangement of hemostasis resulting in either excessive bleeding or clotting, although most typically it is defined as impaired clot formation. Abnormalities in coagulation testing without overt clinical bleeding may also be considered evidence of coagulopathy. This chapter will focus on acquired conditions, such as organ failure, pharmacologic therapies, and platelet dysfunction that are associated with defective clot formation and result in, or exacerbate, intracranial hemorrhage, specifically spontaneous intraparenchymal hemorrhage and traumatic brain injury.

Adverse Drug Reactions in the Intensive Care Unit

Adverse drug reactions (ADRs) are undesirable effects of medications used in normal doses [1]. ADRs can occur during treatment in an intensive care unit (ICU) or result in ICU admissions. A meta-analysis of 4139 studies suggests the incidence of ADRs among hospitalized patients is 17% [2]. Because of underreporting and misdiagnosis, the incidence of ADRs may be much higher and has been reported to be as high as 36% [3]. Critically ill patients are at especially high risk because of medical complexity, numerous high-alert medications, complex and often challenging drug dosing and medication regimens, and opportunity for error related to the distractions of the ICU environment [4]. Table 1 summarizes the ADRs included in this chapter.

If Euhydric and Isotonic Do Not Work, What Are Acceptable pH and Osmolality for Parenteral Drug Dosage Forms?

Parenteral products should aim toward being isotonic and euhydric (physiological pH). Yet, due to other considerations, this goal is often not reasonable or doable. There are no clear allowable ranges related to pH and osmolality, and thus, the objective of this review was to provide a better understanding of acceptable formulation pH, buffer strength, and osmolality taking into account the administration route (i.e., intramuscular, intravenous, subcutaneous) and administration technique (i.e., bolus, push, infusion). This evaluation was based on 3 different approaches: conventional, experimental, and parametric. The conventional way of defining formulation limits was based on standard pH and osmolality ranges. Experimental determination of titratable acidity or in vitro hemolysis testing provided additional drug product information. Finally, the parametric approach was based on the calculation of theoretical values such as (1) the maximal volume of injection which cannot shift the blood's pH or its molarity out of the physiological range and (b) a dilution ratio at the injection site and by verifying that threshold values are not exceeded. The combination of all 3 approaches can support the definition of acceptable pH, buffer strength, and osmolality of formulations and thus may reduce the risk of failure during preclinical and clinical development.

A clinically suspected case of Anaphylactoid reaction to vitamin K injection in a child - a case report and review of literature

Vitamin K is commonly indicated in pediatric patients with coagulopathies. Its commercial preparations are available in the market since long. Minor complications are very well-known, but life-threatening events are rarely reported in children. We present a case of 8-year-old child who developed life-threatening event following intravenous Vitamin K injection. She was survived after cardiopulmonary resuscitation. The reaction was most probably due to anaphylactoid reaction to Vitamin K.

Characterizing the Severe Reactions of Parenteral Vitamin K1

Parenteral vitamin K1 (phytonadione) is used for anticoagulant reversal, and a boxed warning exists with intravenous and intramuscular administration due to the possibility of severe reactions, including fatalities. These reactions resemble hypersensitivity or anaphylaxis, including anaphylactoid reaction, and have led to shock and cardiac and/or respiratory arrest. The objective of this review is to summarize the available literature detailing the anaphylactic/anaphylactoid reactions with parenteral vitamin K1 in order to better characterize the reaction and provide a more in-depth understanding of its importance. A comprehensive literature search of MEDLINE (1946 to June 2016) and EMBASE (1947 to June 2016) was conducted using the terms vitamin K1, phytonadione, phytomenadione, vitamin K group, anaphylaxis, polyoxyethylated castor oil, and cremophor. A total of 2 retrospective surveillance studies, 2 retrospective cohort studies, and 17 case reports were identified for inclusion and assessment. Based on a review of the literature, use of parenteral vitamin K1 may result in severe hypotension, bradycardia or tachycardia, dyspnea, bronchospasm, cardiac arrest, and death. These reactions are most consistent with a nonimmune-mediated anaphylactoid mechanism. It appears that intravenous administration is more frequently associated with these reactions and occurs at an incidence of 3 per 10 000 doses of intravenous vitamin K1. The solubilizer may also increase the risk of adverse reactions, which occurred in patients with and without previous exposure to vitamin K1. Although there are known factors that increase the risk of an adverse drug event occurring, reactions have been reported despite all precautions being properly followed.

The Hidden Culprit: A Case of Repeated Anaphylaxis to Cremophor

Drug-induced anaphylaxis is a big pitfall in patients receiving antineoplastic chemotherapy. We report a case of lung cancer patient who experienced two near-fatal anaphylactic reactions that resulted from paclitaxel and multivitamin, seperately. Recurrent severe reactions to different agents led to further investigation to which material the patient was hypersensitive. The skin prick test revealed sensitization to cremophor, which is a commonly used emulsifying agent. This case emphasizes the importance of correctly identifying the culprit drug of anaphylaxis to avoid potentially fatal reaction.

Fast-track rapid warfarin reversal for elective surgery: extending the efficacy profile to high-risk patients with cancer

Periprocedural management of patients on long-term warfarin therapy remains a common and important clinical issue, with little high-quality data to guide this complex process. The current accepted practice is cessation of warfarin five days preoperatively, but this is not without risk and can be complicated, particularly if bridging is required. An alternative method utilising low-dose intravenous vitamin K the day before surgery has been shown previously to be efficacious, safe and convenient in an elective surgical population receiving chronic warfarin therapy. The efficacy and utility of this 'fast-track' warfarin reversal protocol in surgical patients with cancer, who were at high risk of both thromboembolism and bleeding was investigated in a prospective, single-arm study at a dedicated cancer centre. Seventy-one patients underwent 82 episodes of fast-track warfarin reversal (3 mg intravenous vitamin K 18 to 24 hours before surgery). No patient suffered an adverse reaction to intravenous vitamin K, all but one achieved an International Normalized Ratio =1.5 on the day of surgery, and no surgery was deferred. Assays of vitamin K-dependent factor levels pre- and post-vitamin K demonstrated restoration of functional activity to within an acceptable range for surgical haemostasis. While this alternative method requires further validation in a larger prospective randomised study, we have now extended our use of fast-track warfarin reversal using vitamin K to patients with cancer, on the basis of our experience of its safety, convenience, reliability and efficacy.

Risk Factors for Bleeding in Hospitalized Patients with Elevated INR: No Vitamin K Therapy Received Versus Vitamin K Received

BACKGROUND

Supratherapeutic international normalized ratio (INR) in patients on warfarin is a common side effect. Updated guidelines recommend against using vitamin K to correct INRs 4.5 to 10 in the absence of bleeding. The impact of compliance with updated guidelines during hospitalization has not been fully explored.

METHODS

A retrospective, observational study was performed utilizing electronic medical records. The goal was to evaluate management of supratherapeutic INR values for medicine inpatients and identify differences in clinical outcomes among inpatients treated and not treated with vitamin K. Records from adult inpatients with at least one INR value between 4.5 and 9 were reviewed. A total of 51 records were evaluated. Thirty-four patients did not receive vitamin K compared to 17 who did. Bleeding events, readmissions rates, length of stay, and familiarity with new guidelines were studied.

RESULTS

Mean age of patients was 73 years, and 71% were female. No statistically significant differences were observed in bleeding events between patients who received vitamin K and those who did not: 2/17 (12%) and 1/34 (3%), respectively (P = .30). No differences in 30-day readmission rates (24% vs 18%; P = .71) or in length of stay (7 vs 4 days; P = .11) were found. All pharmacists (13 of 13) were familiar with CHEST 2012 guidelines on the management of supratherapeutic INR compared to 10 of 21 (48%) hospitalists (P = .001).

CONCLUSIONS

With the national focus on reduction of health care costs, health systems are looking at innovative ways to reduce readmission rates and length of stay. This study, which evaluated the use of vitamin K administration, showed no statistical difference between bleeding events, readmission rates, and length of stay in patients who received vitamin K. Education on the updates of guidelines may be beneficial, as many providers were not familiar with the changes in recommendations.

Long-Acting Anticoagulant Rodenticide (Superwarfarin) Poisoning: A Review of Its Historical Development, Epidemiology, and Clinical Management

Long-acting anticoagulant rodenticides (LAARs) inhibit vitamin K epoxide reductase (VKOR). Related bleeding may present a diagnostic challenge and require administration of blood component therapy, hemostatic agents, and vitamin K. This article intends to provide the reader a comprehensive understanding of LAAR poisoning. An exhaustive literature search of PubMed, Science Direct, US National Library of Medicine Toxicology Data Network, and Google Scholar yielded 174 reported cases of LAAR poisoning from which clinical data were extracted and reviewed. In addition, 25 years of epidemiologic data from the American Association of Poison Control Centers was reviewed. In the United States, on average, there were 10413 exposures reported with 2750 patients treated annually. For 25 years, there were 315951 exposures reported with nearly 90% among children and more than 100000 patients treated in a health care facility. Fortunately, only 2% of all exposures result in morbidity or mortality. Inhalational, transcutaneous, and oral routes of exposure have been documented. Most exposures are unintentional. The most frequently reported bleeding sites are mucocutaneous, with hematuria being the most common feature. Deaths were most commonly associated with intracranial hemorrhage. Long-acting anticoagulant rodenticide-induced paradoxical thrombosis and thrombotic complications accompanying hemostatic therapy have also been observed. Most patients present with coagulation assay values beyond measurable limits. Long-acting anticoagulant rodenticides have an extremely high affinity for VKOR compared with warfarin, characterized by rebound coagulopathy and bleeding after initial treatment and the need for high-dose, long-term therapy with vitamin K1. Treatment of acute hemorrhagic symptoms often required intravenous vitamin K1 in excess of 50 to 100 mg; chronic maintenance with 100 mg PO vitamin K1 daily was the most frequently used dose required to suppress coagulopathy. Treatment courses averaged 168 days. Adjunctive hemostatic therapy with recombinant factor VIIa and prothrombin complex concentrate has been reported, and phenobarbital has been used to expedite LAAR metabolism.

An evaluation of intravenous vitamin k for warfarin reversal: are guideline recommendations being followed?

BACKGROUND

Vitamin K antagonists (eg, warfarin) remain the mainstay of anticoagulation therapy in the United States, with over 22 million prescriptions being filled annually. Unfortunately, warfarin therapy is difficult to manage and increases bleeding risk. The 2012 American College of Chest Physicians guidelines created a warfarin reversal algorithm that suggested the stringent use of intravenous vitamin K.

OBJECTIVE

The purpose of this evaluation was to determine the rates of adherence with guideline recommendations in clinical practice.

METHOD

A convenience sample of 3 months of intravenous vitamin K medication administration data (September to November 2013) was obtained to conduct a retrospective review. Patients with underlying hepatic dysfunction or lack of warfarin therapy were excluded. Vitamin K use was evaluated for consistency with the 2012 guidelines.

RESULTS

A total of 364 patients were reviewed and 119 were included. Vitamin K utilization was consistent with guideline recommendations for a total of 30 (25.2%) patients. The most common site of active bleeding requiring reversal was head bleeds, consisting of 56.6% of bleeds. A single dose of 10 mg of vitamin K was the most frequently used dosing strategy. Fresh frozen plasma (73.3%) and four-factor prothrombin complex concentrate (36.7%) were the most commonly used factor products.

CONCLUSION

This evaluation demonstrates that there is a difference between clinical judgment and guideline adherence. True adherence with the guidelines may not be necessary; however, there is room for improvement in both the appropriateness and safety of intravenous vitamin K use.

An Evaluation of Intravenous Vitamin K for Warfarin Reversal: Are Guideline Recommendations Being Followed?

Background

Vitamin K antagonists (eg, warfarin) remain the mainstay of anticoagulation therapy in the United States, with over 22 million prescriptions being filled annually. Unfortunately, warfarin therapy is difficult to manage and increases bleeding risk. The 2012 American College of Chest Physicians guidelines created a warfarin reversal algorithm that suggested the stringent use of intravenous vitamin K.

Objective

The purpose of this evaluation was to determine the rates of adherence with guideline recommendations in clinical practice.

Method

A convenience sample of 3 months of intravenous vitamin K medication administration data (September to November 2013) was obtained to conduct a retrospective review. Patients with underlying hepatic dysfunction or lack of warfarin therapy were excluded. Vitamin K use was evaluated for consistency with the 2012 guidelines.

Results

A total of 364 patients were reviewed and 119 were included. Vitamin K utilization was consistent with guideline recommendations for a total of 30 (25.2%) patients. The most common site of active bleeding requiring reversal was head bleeds, consisting of 56.6% of bleeds. A single dose of 10 mg of vitamin K was the most frequently used dosing strategy. Fresh frozen plasma (73.3%) and four-factor prothrombin complex concentrate (36.7%) were the most commonly used factor products.

Conclusion

This evaluation demonstrates that there is a difference between clinical judgment and guideline adherence. True adherence with the guidelines may not be necessary; however, there is room for improvement in both the appropriateness and safety of intravenous vitamin K use.

Effect of Intravenous Versus Subcutaneous Phytonadione on Length of Stay for Patients in Need of Urgent Warfarin Reversal

This institutional review board-approved retrospective cohort study evaluated the impact of intravenous versus subcutaneous phytonadione on length of stay in hospitalized patients requiring urgent warfarin reversal. All patients were 18 years or older, on warfarin therapy with an international normalized ratio (INR) between 3.1 and 10.0, and had warfarin therapy restarted at discharge. Patients who received intramuscular or oral phytonadione, phytonadione by more than 1 route, fresh frozen plasma, or any other blood products containing clotting factors, patients with active or severe liver disease, and patients who received other forms of anticoagulation were excluded. A total of 4425 patients receiving phytonadione were evaluated and 79 patients were included. Baseline characteristics were similar between the intravenous and subcutaneous groups, including mean age, gender, warfarin indication, Charlson comorbidity index, and indication for phytonadione. Geometric mean length of stay in the intravenous group was 211.7 hours compared with 191.0 hours in the subcutaneous group (P = 0.47). Though intravenous phytonadione administration resulted in significantly lower INRs at all time points <36 hours, geometric mean time to restart of warfarin therapy was not impacted (66.3 hours vs. 64.1 hours, P = 0.72). Despite demonstrating significantly greater INR reductions, hospital length of stay and time to restart of warfarin therapy were not improved with the administration of intravenous over subcutaneous phytonadione.

Comparison of 3-Factor Prothrombin Complex Concentrate and Low-Dose Recombinant Factor VIIa for Warfarin Reversal

Introduction

Prothrombin complex concentrate (PCC) and recombinant Factor VIIa (rFVIIa) have been used for emergent reversal of warfarin anticoagulation. Few clinical studies have compared these agents in warfarin reversal. We compared warfarin reversal in patients who received either 3 factor PCC (PCC3) or low-dose rFVIIa (LDrFVIIa) for reversal of warfarin anticoagulation.

Methods

Data were collected from medical charts of patients who received at least one dose of PCC3 (20 units/kg) or LDrFVIIa (1000 or 1200 mcg) for emergent warfarin reversal from August 2007 to October 2011. The primary end-points were achievement of an INR 1.5 or less for efficacy and thromboembolic events for safety.

Results

Seventy-four PCC3 and 32 LDrFVIIa patients were analyzed. Baseline demographics, reason for warfarin reversal, and initial INR were equivalent. There was no difference in the use of vitamin K or fresh frozen plasma. More LDrFVIIa patients achieved an INR of 1.5 or less (71.9% vs. 33.8%, p =0.001). The follow-up INR was lower after LDrFVIIa (1.25 vs. 1.75, p < 0.05) and the percent change in INR was larger after LDrFVIIa (54.1% vs. 38.8%, p = 0.002). There was no difference in the number of thromboembolic events (2 LDrFVIIa vs. 5 PCC3, p = 1.00), mortality, length of hospital stay, or cost.

Conclusions

Based on achieving a goal INR of 1.5 or less, LDrFVIIa was more likely than PCC3 to reverse warfarin anticoagulation. Thromboembolic events were equivalent in patients receiving PCC3 and LDrFVIIa.

The severe adverse reaction to vitamin k1 injection is anaphylactoid reaction but not anaphylaxis

The severe adverse reaction to vitamin K₁ injection is always remarkable and is thought to result from anaphylaxis. Paradoxically, however, some patients administered vitamin K₁ injection for the first time have adverse reactions. Using beagle dogs, the present study tested the hypothesis that the response to vitamin K₁ is an anaphylactoid reaction. The results showed that serious anaphylaxis-like symptoms appeared in beagle dogs after the administration of vitamin K₁ injection for the first time. The plasma histamine concentration increased, and blood pressure decreased sharply. After sensitization, dogs were challenged with vitamin K₁ injection and displayed the same degree of symptoms as prior to sensitization. However, when the vitamin K₁ injection-sensitized dogs were challenged with a vitamin K₁-fat emulsion without solubilizers such asTween-80, the abnormal reactions did not occur. Furthermore, there was no significant change in the plasma immunoglobulin E concentration after vitamin K₁ challenge. Following treatment with vitamin K₁ injection, the release of histamine and β-hexosaminidase by rat basophilic leukemia-2H3 cells as well as the rate of apoptosis increased. The Tween-80 group displayed results similar to those observed following vitamin K₁ injection in vivo. However, the dogs in the vitamin K₁-fat emulsion group did not display any abnormal behavior or significant change in plasma histamine. Additionally, degranulation and apoptosis did not occur in rat basophilic leukemia-2H3 cells. Our results indicate that the adverse reaction induced by vitamin K₁ injection is an anaphylactoid reaction, not anaphylaxis. Vitamin K₁ injection induces the release of inflammatory factors via a non-IgE-mediated immune pathway, for which the trigger may be the solubilizer.

Rapid reversal of warfarin-associated hemorrhage in the emergency department by prothrombin complex concentrates

Life-threatening warfarin-associated hemorrhage is common, with a high mortality. In the United States, the most commonly used therapies--fresh frozen plasma and vitamin K--are slow and unpredictable and can result in volume overload. Outside of the United States, prothrombin complex concentrates are often used instead; these pooled plasma products reverse warfarin anticoagulation in minutes rather than hours. This article reviews the literature relating to warfarin reversal with fresh frozen plasma, prothrombin complex concentrates, and recombinant factor VIIa and provides elements for a management protocol based on this literature.

Pharmacologic reversal of warfarin-associated coagulopathy in geriatric patients with hip fractures: a retrospective study of thromboembolic events, postoperative complications, and time to surgery

PURPOSE

Patients with acute hip fractures who are on maintenance warfarin for anticoagulation present a significant challenge and their management remains controversial. The purpose of this study was to assess thromboembolic and systemic complications associated with pharmacological reversal of warfarin-associated coagulopathy in a population of geriatric patients with hip fractures.

METHODS

This retrospective cohort study identified patients with operative hip fractures on oral warfarin therapy who had an international normalized ratio (INR) >1.50 on admission (N = 93) approximately over a 13-year span. The control group consisted of patients whose warfarin was held upon admission without further intervention preoperatively (n = 23). The treatment group consisted of patients who underwent pharmacologic reversal of elevated INR with vitamin K and/or fresh frozen plasma (FFP) in addition to holding warfarin (n = 70). Primary outcomes included thromboembolic and other complications as well as mortality within 3 months of presentation. Time to surgery was a secondary outcome.

RESULTS

The 3-month mortality rate was 4% in the pharmacological intervention group and 17% in the watch-and-wait group; this difference trended toward statistical significance (P = .06). There were no significant differences in the likelihoods of other thromboembolic or nonthromboembolic complications between groups. While the difference in mean time to surgery was not significantly different overall between groups, this difference was significant in a subgroup of patients with higher baseline INRs (n = 46, INR >2.17), with a mean difference of 4.0 fewer days until surgery in the pharmacological intervention group (P < .01).

CONCLUSIONS

Pharmacological reversal of warfarin-associated coagulopathy with a combination of vitamin K and FFP appears to be a safe way to optimize patients for operative fixation of hip fractures and is associated with a shorter delay to surgery in patients with more elevated INRs preoperatively.

LEVEL OF EVIDENCE

retrospective cohort study (level III).

Vitamin K dosing to reverse warfarin based on INR, route of administration, and home warfarin dose in the acute/critical care setting

BACKGROUND

Vitamin K is commonly used for reversal of anticoagulation of warfarin. However, the optimal dose and route of vitamin K that does not increase the duration of bridging therapy is unknown.

OBJECTIVE

To determine factors influencing the extent and rate of INR reversal with vitamin K in the acute/critical care setting.

METHODS

This was a chart review of 400 patients who received vitamin K for reversal of warfarin effects between February 2008 and November 2010. Data collected included international normalized ratios (INRs) 12 hours, 24 hours, and 48 hours prior to vitamin K administration; intravenous or oral vitamin K dose; and whether or not fresh frozen plasma (FFP) was administered.

RESULTS

Intravenous vitamin K reduced INR more rapidly than oral vitamin K (5.09, 1.91, 1.54, and 1.41 vs 5.67, 2.90, 2.14, and 1.58) at baseline, 12, 24, and 48 hours, respectively. The dose of vitamin K (p < 0.001), route of administration (p < 0.001), and baseline INR (p < 0.001) influenced subsequent INR values. The INR reduction was similar for intravenous vitamin K doses 2 mg or greater. Home warfarin dose did not affect INR responses to intravenous (p = 0.27) or oral vitamin K (p = 0.98). FFP did not influence INR values at 48 hours. Although longer anticoagulation bridge therapy seemed to be associated with higher vitamin K doses, the incidence (p = 0.63) and duration (p = 0.61) were not significant.

CONCLUSIONS

Vitamin K dose, route, and initial INR influence subsequent INR values. INR reduction is similar for intravenous vitamin K doses of 2 mg or greater. Preadministration of FFP does not alter INR values at 48 hours or more after vitamin K administration.

Treatment of warfarin-associated coagulopathy with vitamin K

Warfarin is the most common form of oral anticoagulant therapy. Although it has indisputable benefit in the management of thromboembolic disease, warfarin-associated coagulopathy (WAC) is a well-documented complication of its use. As warfarin exerts its effect by impairing formation of the vitamin K-dependent clotting factors, a cornerstone of WAC management is vitamin K replacement. Daily vitamin K supplementation is an emerging approach to regulate international normalized ratios in difficult-to-control patients. Mild WAC without bleeding can often be managed with warfarin withdrawal alone. For excessive international normalized ratio elevation in the absence of bleeding, low-dose oral vitamin K (1?2.5 mg) is sufficient and achieves the same degree of international normalized ratio correction by 24 h as intravenous therapy. The stable patient with WAC and minor bleeding can also be given oral vitamin K, with correction of the underlying defect. Major bleeding should first be managed with factor replacement for immediate correction of the coagulopathy, using either a prothrombin complex concentrate or fresh-frozen plasma. High-dose vitamin K (10 mg) should be given concurrently via intravenous infusion to confer lasting correction. Warfarin resistance and vitamin K-associated anaphylaxis are rare. Despite development of new oral anticoagulant therapy compounds, warfarin will probably retain a prominent role in thromboembolism management for several years to come.

Management of bleeding complications in the anticoagulated patient

As new anticoagulants become available, and the number of anticoagulated patients continues to rise, it is necessary to know how to deal with associated bleeding complications. In this review, reversal strategies for traditional anticoagulants (warfarin and heparin) as well as newer anticoagulants are described. Prothrombin complex concentrates (PPCs) can be used to reverse vitamin K antagonists (VKA), and plasma may be used where they are not available. Recombinant activated factor VII (rFVIIa) may be useful to reverse pentasaccharide anticoagulants. 1-Desamino-8-D-arginine vasopressin (DDAVP), cryoprecipitate, PCCs, and dialysis may help to reverse direct thrombin inhibitors, while rFVIIa seems to be ineffective. The effect of direct factor Xa inhibitors may be reversed by PCCs, FVIIa, or factor Xa concentrates.

Oral anticoagulant therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

The objective of this article is to summarize the published literature concerning the pharmacokinetics and pharmacodynamics of oral anticoagulant drugs that are currently available for clinical use and other aspects related to their management.

METHODS

We carried out a standard review of published articles focusing on the laboratory and clinical characteristics of the vitamin K antagonists; the direct thrombin inhibitor, dabigatran etexilate; and the direct factor Xa inhibitor, rivaroxaban

RESULTS

The antithrombotic effect of each oral anticoagulant drug, the interactions, and the monitoring of anticoagulation intensity are described in detail and discussed without providing specific recommendations. Moreover, we describe and discuss the clinical applications and optimal dosages of oral anticoagulant therapies, practical issues related to their initiation and monitoring, adverse events such as bleeding and other potential side effects, and available strategies for reversal.

CONCLUSIONS

There is a large amount of evidence on laboratory and clinical characteristics of vitamin K antagonists. A growing body of evidence is becoming available on the first new oral anticoagulant drugs available for clinical use, dabigatran and rivaroxaban.

Drug allergy: an updated practice parameter

Adverse drug reactions (ADRs) result in major health problems in the United States in both the inpatient and outpatient setting. ADRs are broadly categorized into predictable (type A and unpredictable (type B) reactions. Predictable reactions are usually dose dependent, are related to the known pharmacologic actions of the drug, and occur in otherwise healthy individuals, They are estimated to comprise approximately 80% of all ADRs. Unpredictable are generally dose independent, are unrelated to the pharmacologic actions of the drug, and occur only in susceptible individuals. Unpredictable reactions are subdivided into drug intolerance, drug idiosyncrasy, drug allergy, and pseudoallergic reactions. Both type A and B reactions may be influenced by genetic predisposition of the patient

International normalised ratio normalisation in patients with coumarin-related intracranial haemorrhages--the INCH trial: a randomised controlled multicentre trial to compare safety and preliminary efficacy of fresh frozen plasma and prothrombin complex--study design and protocol

BACKGROUND

Intracerebral haemorrhage is the most feared complication in patients who are on treatment with vitamin K antagonists. Vitamin K antagonist related intracerebral haemorrhage occurs in about 10% of patients. Intracerebral haemorrhage has the worst prognosis of all subtypes of stroke including spontaneous intracerebral haemorrhage, and a mortality rate of up to about 65%. The higher rate of haematoma expansion due to rebleeding is thought to be responsible for the higher mortality. Current international treatment recommendations include fresh frozen plasma and prothrombin complex concentrate. It is known that these substances lower the international normalised ratio, and thus it is assumed that normalisation of coagulopathy may lead to haemostasis and reduction of rebleeding. However, the issue of whether to use fresh frozen plasma or prothrombin complex concentrate for urgent reversal of vitamin K antagonists is unresolved: safety and efficacy of these treatments have never been studied in a randomised controlled trial. Our questions are: how effective are the two substances in normalisation of the international normalized ratio? How feasible is it to apply either of these treatments in an acute situation? What is the safety profile of each of these substances? Is there a difference in haematoma growth and clinical outcome?

METHOD

We designed a prospective, randomised, controlled multicentre trial to compare biological efficacy and safety of fresh frozen plasma and prothrombin complex concentrate in vitamin K antagonist related intracerebral haemorrhage. The study is observer-blinded for laboratory, neuroradiological, and clinical outcomes. Patients will be included if a computed tomography scan shows an intraparenchymal or subdural haematoma within 12 h after onset of symptoms, if the patient is on treatment with vitamin K antagonists, and the international normalized ratio is ≥2. Primary endpoint is the normalisation of the international normalized ratio (≤1·2) within three-hours after the start of antagonising therapy. Main exclusion criteria are secondary intracerebral haemorrhage, other known coagulopathies, and known acute ischaemic events.

DISCUSSION

We discuss the rationale of our trial on the basis of the current recommendations and specific aspects of trial design as, time window, choice of endpoints, dosing of fresh frozen plasma and prothrombin complex concentrate, monitoring and analysis of safety parameters, and rescue treatment.

CONCLUSION

This will be the first prospective trial comparing fresh frozen plasma and prothrombin complex concentrate in the indication of vitamin K antagonist related intracerebral hemorrhage. Recruitment of subjects started in August 2009. Until now, 19 patients have been included.