Toxicity from repeated doses of acetaminophen in children: assessment of causality and dose in reported cases.

Liver injury has been reported in children treated with repeated doses of acetaminophen. The objective of this study was to identify and validate reports of liver injury or death in children younger than 6 years who were administered repeated therapeutic doses of acetaminophen. We reviewed US Poison Center data, peer-reviewed literature, US Food and Drug Administration Adverse Event Reports, and US Manufacturer Safety Reports describing adverse effects after acetaminophen administration. Reports that described hepatic abnormalities (description of liver injury or abnormal laboratory testing) or death after acetaminophen administration to children younger than 6 years were included. The identified reports were double abstracted and then reviewed by an expert panel to determine if the hepatic injury was related to acetaminophen and whether the dose of acetaminophen was therapeutic (≤75 mg/kg) or supratherapeutic. Our search yielded 2531 reports of adverse events associated with acetaminophen use. From these cases, we identified 76 cases of hepatic injury and 26 deaths associated with repeated acetaminophen administration. There were 6 cases of hepatic abnormalities and no deaths associated with what our panel determined to be therapeutic doses. A large proportion of cases could not be fully evaluated due to incomplete case reporting. Although we identified numerous examples of liver injury and death after repeated doses of acetaminophen, all the deaths and all but 6 cases of hepatic abnormalities involved doses more than 75 mg/kg per day. This study suggests that the doses of less than 75 mg/kg per day of acetaminophen are safe for children younger than 6 years.

Short-term outcomes after Fab antivenom therapy for severe crotaline snakebite.

STUDY OBJECTIVES: We seek to determine the short-term outcomes associated with the use of Crotalidae polyvalent immune Fab (ovine) (CroFab; FabAV) therapy for severe crotaline snake envenomation and to better define the incidence of hypersensitivity reactions associated with FabAV use. METHODS: We conducted a multicenter observational case series study of patients who received FabAV at 17 US hospitals in 2002 to 2004. A 7-point score incorporating local, systemic, and hematologic venom effects was used to grade envenomation severity before and after FabAV therapy. The primary outcome for response to therapy was the change in overall envenomation severity after FabAV administration. The primary safety outcomes were the rates of immediate hypersensitivity reactions and serum sickness. RESULTS: The outcome-evaluable population included 209 patients, of whom 28 had severe envenomation. All severely envenomated patients improved after receiving FabAV. The median severity scores of severely envenomated patients were 5 (interquartile range [IQR] 5 to 5) before FabAV, 1 (IQR 1 to 2) at the last FabAV loading dose, and 1 (IQR 0 to 1) at the last clinical observation. The proportion of patients with progressive pain, progressive swelling, cardiovascular effects, respiratory effects, neurologic effects, gastrointestinal effects, coagulopathy, and thrombocytopenia all improved after FabAV therapy. The safety population included 247 patients. Immediate hypersensitivity reactions were reported in 6.1% (95% confidence interval 3.4% to 9.8%) of patients. Serum sickness was reported in 5% (95% confidence interval 0.6% to 17%) of patients with a minimum of 6 days of follow-up after the last dose of FabAV. CONCLUSION: FabAV therapy is associated with clinical improvement in severe crotaline snake envenomation. Immediate hypersensitivity and serum sickness rates may be less than described in the FabAV prescribing information.

Factors associated with difficulty achieving initial control with crotalidae polyvalent immune fab antivenom in snakebite patients.

BACKGROUND: The prescribing information for Crotalidae Fab antivenom (FabAV) instructs clinicians to administer FabAV until initial control of the envenomation syndrome is achieved. Risk factors for difficulty achieving initial control are not known. OBJECTIVES: The study aim was to identify factors present before administration of antivenom associated with difficulty achieving initial control. METHODS: The authors conducted a retrospective study of all patients presenting to any one of 17 centers and receiving FabAV from 2002 to 2004. Demographic and historical information, as well as data about nine specific venom effects, were collected prior to the administration of antivenom. An expert panel used standard criteria to determine if initial control was achieved. The patient group that had difficulty achieving initial control was compared to the group that achieved initial control, and adjusted odds ratios were calculated using stepwise logistic regression. RESULTS: A total of 247 patients were included in the final analysis. The majority of patients were envenomated on the upper extremity and were young males. A total of 203 patients (82.2%) achieved initial control. In univariate analysis, thrombocytopenia, bleeding, neurologic effects, and a severe bite were significantly associated with difficulty achieving initial control. After logistic regression, the presence of neurologic effects and thrombocytopenia remained significantly associated with difficulty achieving initial control. When both factors were present, the patient was 13.8 times more likely to have difficulty achieving initial control. CONCLUSIONS: A number of factors were present before the administration of FabAV that were independently associated with difficulty achieving initial control of the envenomation syndrome. Predicting which patients will have difficulty achieving initial control has important ramifications for patient disposition and may provide insight into the mechanisms for lack of antivenom efficacy.

Treatment of chronically digoxin-poisoned patients with a newer digoxin immune fab--a retrospective study.

CONTEXT: Digoxin is used in the treatment of patients with cardiac dysfunction, though toxicity sometimes results from the use of this medication. In 1986, the US Food and Drug Administration (FDA) approved a digoxin immune Fab for the treatment of such patients. In 2001, the FDA approved a newer digoxin immune Fab, a digoxin-specific antibody (DSAb) known as DigiFab (Protherics Inc, Brentwood, Tennessee), though minimal literature exists on the clinical effects of this DSAb. OBJECTIVES: To characterize a cohort of patients presenting with chronic digoxin toxicity and to describe the clinical course of these patients with the use of DSAb. METHODS: A retrospective study included patients with life-threatening cardiotoxicity and serum digoxin level greater than 2 ng/mL who were treated at two US hospitals from 2003 to 2006. Trained investigators abstracted data from patients' medical records and assessed changes in clinical and laboratory parameters at regular intervals (0-4, >4-12, >12-24, and >24-72 hours) after treatment with DSAb. An expert panel reviewed electrocardiogram results to identify life-threatening manifestations of digoxin toxicity before and after DSAb treatment. Efficacy of treatment was assessed as rates of improvement in clinical parameters and cardiotoxic effects. Rates of adverse drug reactions were used to characterize safety. All data were analyzed with descriptive statistics. RESULTS: Fourteen patients (mean [SD] age, 71.3 [10.4] years) were treated for chronic digoxin toxicity. At presentation, 12 patients had a heart rate of less than 45 beats per minute, 1 had third-degree heart block, and 1 had asystole. Mean serum digoxin level was 3.6 ng/mL. Eleven patients had abnormal renal function. After administration of DSAb, clinical parameters improved in all patients. Within 24 hours, cardiotoxicity resolved in 7 of 9 evaluable patients. Two adverse drug reactions possibly related to DigiFab occurred, both of which resolved with conventional measures. Two patients died from conditions unrelated to treatment. CONCLUSION: The newer DSAb appears to be a safe and effective treatment for resolving digoxin toxicity in adults, as indicated by electrocardiogram and clinical assessments. Because patients with multiple comorbidities may be at greater risk for digoxin toxicity, they should be closely monitored during treatment with digoxin.

A multicenter comparison of the safety of oral versus intravenous acetylcysteine for treatment of acetaminophen overdose.

UNLABELLED: Oral and intravenous (IV) N-acetylcysteine (NAC) are used for the treatment of acetaminophen poisoning. The objective of this multicenter study was to compare the safety of these two routes of administration. METHODS: We conducted a multicenter chart review of all patients treated with NAC for acetaminophen poisoning. The primary safety outcome was the percentage of patients with NAC-related adverse events. RESULTS: A total of 503 subjects were included in the safety analysis (306 IV-only, 145 oral-only, and 52 both routes). There were no serious adverse events related to NAC for either route. Nausea and vomiting were the most common related adverse events and were more common with oral treatment (23 vs. 9%). Anaphylactoid reactions were more common with IV administration (6 vs. 2%). CONCLUSIONS: IV and oral NAC are generally mild adverse drug reactions.

Crotaline Fab antivenom appears to be effective in cases of severe North American pit viper envenomation: an integrative review.

BACKGROUND: In 2000, the United States Food and Drug Administration approved Crotalidae Polyvalent Immune Fab (Ovine) (hereafter, FabAV), "for the management of patients with minimal to moderate North American Crotalid envenomation." Because whole-IgG pit viper antivenom is no longer available in the United States, FabAV is currently the only specific treatment option available to United States clinicians treating snakebite victims of any severity. No clinical trial data are available concerning the effectiveness of FabAV for treatment of severe snakebite, but several published articles describe its use in this setting. METHODS: We performed a comprehensive review of the English-language medical literature to identify all publications (1996 to July, 2008) containing data about the administration of FabAV. Two trained reviewers separately extracted case-level data concerning the administration of FabAV to patients with severe envenomation by North American crotaline snakes to a standardized form. Descriptive statistics were used. In addition, we hand-searched the US National Poison Data System reports for the years 2000-2006 to identify and describe any reports of death that occurred after FabAV administration. RESULTS: The literature review found 147 unique publications regarding FabAV. Twenty-four evaluable cases of severe human envenomation treated with FabAV were identified in 19 publications. Seven cases were described in five cohort studies, and 17 cases were described in 14 single patient case reports or non-cohort case series. Sixty-five specific severe venom effects were reported in these 24 patients, of which 50 effects (77%) improved or resolved after FabAV therapy. Initial control of all severe venom effects was achieved in 12 patients (50%). The rate at which initial control was achieved was significantly higher among patients reported in the cohort series than in the case series and non-cohort reports (100% vs. 29%, P = 0.005). The median dose of FabAV used to obtain initial control was 6 vials (range: 4 - 18 vials). Nine patients had severe venom effects that persisted despite FabAV therapy. Recurrent and/or delayed-onset severe defibrination syndrome occurred in 12 patients, most of whom did not receive recommended maintenance FabAV dosing. No patient developed systemic bleeding. CONCLUSION: In this structured literature review, FabAV appears to be effective in the management of severe crotaline snake envenomation. Incomplete response to therapy, recurrence of venom effects, and delayed-onset venom effects were reported in case reports, but not reported in cohort studies.

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.

A randomized controlled trial of a smoking cessation intervention for pregnant adolescents.

BACKGROUND: The smoking prevalence rate among pregnant adolescents has been estimated at 59-62%, and 60-80% of these adolescents continue to smoke throughout their pregnancies. OBJECTIVES: The aim of this study was to evaluate the short- and long-term effects of smoking cessation strategies tailored to the pregnant adolescent to attain and maintain abstinence. The specific aim was to examine differences in short- and long-term smoking behaviors among three groups: Teen FreshStart (TFS), Teen FreshStart Plus Buddy (TFS-B), and Usual Care (UC) control. METHODS: In this randomized controlled intervention study, a 3-group (TFS, TFS-B, and UC) by 3-occasion (baseline, 8 weeks postrandomization, and 1-year following study entry) design was used. The study included 142 pregnant adolescents who were aged 14 to 19 years. Both self-reported smoking status collected on the Smoking History Questionnaire and saliva cotinine levels were used to identify smoking behaviors. RESULTS: There were no significant differences among the three treatment groups at baseline in terms of the racial distribution, age, gestational age, age of menses initiation, number in family household, number of family members who smoked, or tobacco use. A significant difference between the UC group and the TFS-B group (p = .010) was seen in smoking behaviors measured 8 weeks following treatment initiation. At 1 year following study entry, however, there were no differences between the groups in smoking behaviors. DISCUSSION: The TFS-B intervention was more effective in attaining short-term smoking cessation in the pregnant adolescent than TFS or UC. Findings suggest that the peer-enhanced programming had a limited effect but could not sustain the participant beyond postpartum (1 year following study entry). Future studies should include relapse prevention to sustain smoking abstinence into the postpartum period.