Victoria E. Anderson

Expert Consensus Guidelines for Stocking of Antidotes in Hospitals That Provide Emergency Care

STUDY OBJECTIVE We developed recommendations for antidote stocking at hospitals that provide emergency care. METHODS An expert panel representing diverse perspectives (clinical pharmacology, clinical toxicology, critical care medicine, clinical pharmacy, emergency medicine, internal medicine, pediatrics, poison centers, pulmonary medicine, and hospital accreditation) was formed to create recommendations for antidote stocking. Using a standardized summary of the medical literature, the primary reviewer for each antidote proposed guidelines for antidote stocking to the full panel. The panel used a formal iterative process to reach their recommendation for the quantity of an antidote that should be stocked and the acceptable period for delivery of each antidote. RESULTS The panel recommended consideration of 24 antidotes for stocking. The panel recommended that 12 of the antidotes be available for immediate administration on patient arrival. In most hospitals, this period requires that the antidote be stocked in the emergency department. Another 9 antidotes were recommended for availability within 1 hour of the decision to administer, allowing the antidote to be stocked in the hospital pharmacy if the hospital has a mechanism for prompt delivery of antidotes. The panel identified additional antidotes that should be stocked by the hospital but are not usually needed within the first hour of treatment. The panel recommended that each hospital perform a formal antidote hazard vulnerability assessment to determine the need for antidote stocking in that hospital. CONCLUSION The antidote expert recommendations provide a tool to be used in creating practices for appropriate and adequate antidote stocking in hospitals that provide emergency care.

The Efficacy of Crotalidae Polyvalent Immune Fab (Ovine) Antivenom Versus Placebo Plus Optional Rescue Therapy on Recovery From Copperhead Snake Envenomation: A Randomized, Double-Blind, Placebo-Controlled, Clinical Trial

Study objective Copperhead snake (Agkistrodon contortrix) envenomation causes limb injury resulting in pain and disability. It is not known whether antivenom administration improves limb function. We determine whether administration of antivenom improves recovery from limb injury in patients envenomated by copperhead snakes. Methods From August 2013 through November 2015, we performed a multicenter, randomized, double‐blind, placebo‐controlled, clinical trial to evaluate the effect of ovine Crotalidae polyvalent immune Fab (ovine) (CroFab; FabAV) antivenom therapy on recovery of limb function in patients with copperhead snake envenomation at 14 days postenvenomation. The study setting was 18 emergency departments in regions of the United States where copperhead snakes are endemic. Consecutive patients aged 12 years or older with mild‐ to moderate‐severity envenomation received either FabAV or placebo. The primary outcome was limb function 14 days after envenomation, measured by the Patient‐Specific Functional Scale. Additional outcomes included the Patient‐Specific Functional Scale at other points; the Disorders of the Arm, Shoulder, and Hand, Lower Extremity Functional Scale, and Patient’s Global Impression of Change instruments; grip strength; walking speed; quality of life (Patient‐Reported Outcomes Measurement Information System Physical Fucntion‐10); pain; and analgesic use. Results Seventy‐four patients received study drug (45 FabAV, 29 placebo). Mean age was 43 years (range 12 to 86 years). Fifty‐three percent were men, 62% had lower extremity envenomation, and 88% had mild initial severity. The primary outcome, the least square mean Patient‐Specific Functional Scale score at 14 days postenvenomation, was 8.6 for FabAV‐treated subjects and 7.4 for placebo recipients (difference 1.2; 95% confidence interval 0.1 to 2.3; P=.04). Additional outcome assessments generally favored FabAV. More FabAV‐treated subjects experienced treatment‐emergent adverse events (56% versus 28%), but few were serious (1 in each group). Conclusion Treatment with FabAV reduces limb disability measured by the Patient‐Specific Functional Scale 14 days after copperhead envenomation.

Acute hepatotoxicity associated with therapeutic doses of intravenous acetaminophen

Abstract Background: IV acetaminophen at 4 g per day is considered safe, producing no hepatic failure in more than 1400 cases. Oxidation of acetaminophen forms a reactive intermediate that binds to cellular proteins resulting in acetaminophen-protein adducts (APAP-CYS). Serum concentrations of APAP-CYS have been found to correlate with acetaminophen-induced hepatotoxicity. We report a case of hepatotoxicity associated with therapeutic doses of IV acetaminophen, with elevated serum APAP-CYS. Case details: The patient was a 92-year-old, 68 kg woman without known hepatic disease or ethanol abuse. On hospital day 3 she underwent laparoscopic reduction of internal hernias under general anesthesia. Surgery was uncomplicated and postoperatively she was treated with subcutaneous heparin and IV acetaminophen, 1 g every 6 h for almost 4 days (total dose = 13 g). At the start of therapy, transaminases were normal. On hospital day 5, she was noted to have marked transaminase elevations (AST: 4698 IU/L; ALT: 3914 IU/L) with increases in INR (1.68), ammonia (60 mcg/dL), and total bilirubin (1.8 mg/dL). Serum acetaminophen concentration was 15.3 mcg/mL 26 h after her last dose. Acetaminophen was discontinued and IV acetylcysteine was given and continued at the second maintenance dose rate for a second 16-hour infusion, at which time transaminases, INR, ammonia and total bilirubin were all improving. The patient was discharged 2 days later. Serum APAP-CYS concentrations in serum samples obtained during her hospitalization were elevated (peak = 4.81 μM on hospital day 5; expected range for therapeutic dosing <1.1 μM). Case discussion: We have identified a case of acute liver injury associated with therapeutic dosing of IV acetaminophen. The serum APAP-CYS concentrations are consistent with that seen in cases of hepatotoxicity following repeated supratherapeutic acetaminophen ingestion. Several factors that likely contributed to her susceptibility included advanced age, post-operative status, a likely catabolic state and multiple acetaminophen doses over several days. These uncommon circumstances limit the generalizability of risk. We believe the findings are most consistent with acetaminophen-induced liver injury. Conclusion: This case illustrates a potential hazard of IV acetaminophen and demonstrates the potential utility of APAP-CYS adducts in evaluating causality in acute liver injury.

Serum Acetaminophen Protein Adduct Concentrations in Pediatric Emergency Department Patients.

Objectives: Acetaminophen toxicity is a common cause of pediatric liver failure. The diagnosis may be limited by the short window of detection of acetaminophen in serum. Recently acetaminophen protein adducts (APAP-CYS) have been used as a biomarker with a longer duration of detection. The objective of this study was to describe the serum concentrations of APAP-CYS in pediatric patients with and without reported therapeutic acetaminophen exposure. Methods: A cross-sectional study of children age 1 to <12 years presenting to a pediatric emergency department. Subjects were stratified by recent acetaminophen use and had serum APAP-CYS measured using LC/MS. Results: One hundred patients were enrolled. All of the patients whose caregivers denied acetaminophen exposure had nondetectable APAP-CYS. Fifty-two percent of subjects who were reported to have taken acetaminophen in the preceding 2 weeks had detectable serum APAP-CYS. The APAP-CYS concentrations were positively correlated with higher overall dose and more recent ingestion. Conclusions: APAP-CYS is detectable in the majority of children taking acetaminophen and not detected in the majority of children who are not exposed to acetaminophen.

Accuracy of the Structured Medication History Assessment Tool (MedHAT) Compared with Recorded Real-Time Medication Use

Medication histories are collected to measure drug exposure in epidemiologic studies, to identify adverse drug events and in clinical practice. The objective of this study was to compare the accuracy of a structured medication history obtained by using the Medication History Assessment Tool (MedHAT) with a medication diary in which subjects recorded real‐time medication use.

Serum paracetamol-protein adducts in ambulatory subjects: Relationship to recent reported paracetamol use

Abstract Context: Serum paracetamol-protein adducts (PPAs) are a novel potential biomarker of paracetamol exposure. The relationship between serum PPA concentrations and reported paracetamol use in ambulatory adults has not been previously described. Materials and methods: This was a cross-sectional study of ambulatory adults. A detailed medication history was obtained from all subjects and subjects were stratified by reported paracetamol use in the 2 weeks prior to enrolment. Serum PPAs were measured in all subjects and correlated with reported dose, time of last ingestion and demographics. Results: We enrolled 230 in the paracetamol exposure arm and 74 in the no exposure arm. 98/230 (42.6%)of subjects who reported paracetamol exposure had PPA detected and 68/74 (91.9%) of subjects who denied paracetamol exposure had no PPA detected. PPA concentrations were positively correlated with total paracetamol dose and with more recent ingestion. Discussion: Detection of serum PPA generally reflects paracetamol exposure histories in ambulatory adults. Concentrations are well correlated with reported dose and time from last dose. Conclusions: Serum PPA can be detected with reported therapeutic use of paracetamol but may not be detected in all patients who report taking paracetamol.

Medication history assessment in research: A randomized controlled trial comparing tablet-based (eMedHAT) versus structured interview (MedHAT)

Accurate capture of medication use is important for high quality research. For epidemiologic studies, medication histories are the most common measure of exposure when trying to identify associations between medications and outcomes. Concomitant medications can alter the efficacy or safety of study drugs in clinical trials. However, there are few studies evaluating the accuracy and efficiency of methods to collect these histories. The objective of this study is to compare the accuracy of medication histories collected by structured interview to histories captured using a tablet‐based application.

Early administration of Fab antivenom resulted in faster limb recovery in copperhead snake envenomation patients

Abstract Background: No previous research has studied whether early snake antivenom administration leads to better clinical outcomes than late antivenom administration in North American pit viper envenomation. Methods: A secondary analysis of data from a clinical trial of Fab antivenom (FabAV) versus placebo for copperhead snake envenomation was conducted. Patients treated before the median time to FabAV administration were classified as receiving early treatment and those treated after the median time were defined as the late treatment group. A Cox proportional hazards model was used to compare time to full recovery on the Patient-Specific Functional Scale (PSFS) instrument between groups. Secondary analyses compared estimated mean PSFS scores using a generalized linear model and the estimated proportion of patients with full recovery at each time point using logistic regression. To evaluate for confounding, the main analysis was repeated using data from placebo-treated subjects. Results: Forty-five subjects were treated with FabAV at a median of 5.47 h after envenomation. Patients in the early treatment group had a significantly shorter time to full recovery than those treated late (median time: 17 versus 28 days, p = .025). Model-estimated PSFS scores were numerically higher at each time point in the early group. No difference was found between patients treated early versus late with placebo. Conclusions: In this secondary analysis of trial data, recovery of limb function was faster when Fab antivenom was administered soon after envenomation, as opposed to late administration.