Colchicine for prevention of postpericardiotomy syndrome and postoperative atrial fibrillation: the COPPS-2 randomized clinical trial

IMPORTANCE

Postpericardiotomy syndrome, postoperative atrial fibrillation (AF), and postoperative effusions may be responsible for increased morbidity and health care costs after cardiac surgery. Postoperative use of colchicine prevented these complications in a single trial.

OBJECTIVE

To determine the efficacy and safety of perioperative use of oral colchicine in reducing postpericardiotomy syndrome, postoperative AF, and postoperative pericardial or pleural effusions.

DESIGN, SETTING, AND PARTICIPANTS

Investigator-initiated, double-blind, placebo-controlled, randomized clinical trial among 360 consecutive candidates for cardiac surgery enrolled in 11 Italian centers between March 2012 and March 2014. At enrollment, mean age of the trial participants was 67.5 years (SD, 10.6 years), 69% were men, and 36% had planned valvular surgery. Main exclusion criteria were absence of sinus rhythm at enrollment, cardiac transplantation, and contraindications to colchicine.

INTERVENTIONS

Patients were randomized to receive placebo (n=180) or colchicine (0.5 mg twice daily in patients ≥70 kg or 0.5 mg once daily in patients <70 kg; n=180) starting between 48 and 72 hours before surgery and continued for 1 month after surgery.

MAIN OUTCOMES AND MEASURES

Occurrence of postpericardiotomy syndrome within 3 months; main secondary study end points were postoperative AF and pericardial or pleural effusion.

RESULTS

The primary end point of postpericardiotomy syndrome occurred in 35 patients (19.4%) assigned to colchicine and in 53 (29.4%) assigned to placebo (absolute difference, 10.0%; 95% CI, 1.1%-18.7%; number needed to treat = 10). There were no significant differences between the colchicine and placebo groups for the secondary end points of postoperative AF (colchicine, 61 patients [33.9%]; placebo, 75 patients [41.7%]; absolute difference, 7.8%; 95% CI, -2.2% to 17.6%) or postoperative pericardial/pleural effusion (colchicine, 103 patients [57.2%]; placebo, 106 patients [58.9%]; absolute difference, 1.7%; 95% CI, -8.5% to 11.7%), although there was a reduction in postoperative AF in the prespecified on-treatment analysis (placebo, 61/148 patients [41.2%]; colchicine, 38/141 patients [27.0%]; absolute difference, 14.2%; 95% CI, 3.3%-24.7%). Adverse events occurred in 21 patients (11.7%) in the placebo group vs 36 (20.0%) in the colchicine group (absolute difference, 8.3%; 95% CI; 0.76%-15.9%; number needed to harm = 12), but discontinuation rates were similar. No serious adverse events were observed.

CONCLUSIONS AND RELEVANCE

Among patients undergoing cardiac surgery, perioperative use of colchicine compared with placebo reduced the incidence of postpericardiotomy syndrome but not of postoperative AF or postoperative pericardial/pleural effusion. The increased risk of gastrointestinal adverse effects reduced the potential benefits of colchicine in this setting.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01552187.

Comparative safety of anti-epileptic drugs among infants and children exposed in utero or during breastfeeding: protocol for a systematic review and network meta-analysis

BACKGROUND

Epilepsy affects about 1% of the general population. Anti-epileptic drugs (AEDs) prevent or terminate seizures in individuals with epilepsy. Pregnant women with epilepsy may continue taking AEDs. Many of these agents cross the placenta and increase the risk of major congenital malformations, early cognitive and developmental delays, and infant mortality. We aim to evaluate the comparative safety of AEDs approved for chronic use in Canada when administered to pregnant and breastfeeding women and the effects on their infants and children through a systematic review and network meta-analysis.

METHODS

Studies examining the effects of AEDs administered to pregnant and breastfeeding women regardless of indication (e.g., epilepsy, migraine, pain, psychiatric disorders) on their infants and children will be included. We will include randomized clinical trials (RCTs), quasi-RCTs, non-RCTs, controlled before-after, interrupted time series, cohort, registry, and case-control studies. The main literature search will be executed in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials. We will seek unpublished literature through searches of trial protocol registries and conference abstracts. The literature search results screening, data abstraction, and risk of bias appraisal will be performed by two individuals, independently. Conflicts will be resolved through discussion. The risk of bias of experimental and quasi-experimental studies will be appraised using the Cochrane Effective Practice and Organization of Care Risk-of-Bias tool, methodological quality of observational studies will be appraised using the Newcastle-Ottawa Scale, and quality of reporting of safety outcomes will be conducted using the McMaster Quality Assessment Scale of Harms (McHarm) tool. If feasible and appropriate, we will conduct random effects meta-analysis. Network meta-analysis will be considered for outcomes that fulfill network meta-analysis assumptions.The primary outcome is major congenital malformations (overall and by specific types), while secondary outcomes include fetal loss/miscarriage, minor congenital malformations (overall and by specific types), cognitive development, psychomotor development, small for gestational age, preterm delivery, and neonatal seizures.

DISCUSSION

Our systematic review will address safety concerns regarding the use of AEDs during pregnancy and breastfeeding. Our results will be useful to healthcare providers, policy-makers, and women of childbearing age who are taking anti-epileptic medications.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42014008925.

Safety and effectiveness of antiretroviral therapies for HIV-infected women and their infants and children: protocol for a systematic review and network meta-analysis

BACKGROUND

Antiretroviral therapy reduces mother-to-child transmission of human immunodeficiency virus (HIV) during pregnancy, delivery, and breastfeeding. However, these agents have been associated with preterm birth, anemia and low birth weight. We aim to evaluate the comparative safety and effectiveness of the use of antiretroviral drugs among HIV-infected women and the effects on their infants and children through a systematic review and network meta-analysis.

METHODS/DESIGN

Studies examining the effects of six antiretroviral drug classes (nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors, integrase inhibitors, fusion inhibitors, co-receptor inhibitors) administered to HIV-infected pregnant women will be included. We will include randomized clinical trials (RCTs), quasi-RCTs, non-RCTs, controlled before-after, interrupted time series, cohort, registry, and case-control studies. No limitations will be imposed on publication status (that is, unpublished studies are eligible for inclusion), duration of follow-up, study conduct period, and language of dissemination. Comprehensive literature searches will be conducted in major electronic databases, including MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials. Gray literature will be identified through searching dissertation databases, trial protocol registries, and conference abstracts.Two team members will independently screen all citations, full-text articles, and abstract data; conflicts will be resolved through discussion. The risk of bias and methodological quality will be appraised using appropriate tools (for example, Cochrane Collaboration's tool for assessing risk of bias, Newcastle-Ottawa Scale, and McMaster Quality Assessment Scale of Harms). If feasible and appropriate, we will conduct random effects meta-analysis. Network meta-analysis will be considered for outcomes with the greatest number of treatment comparisons available that fulfill network meta-analysis assumptions (for example, consistency of evidence between direct and indirect data, and low statistical heterogeneity between included studies).The primary effectiveness outcome is mother-to-child transmission of HIV, and the primary safety outcome is major congenital malformation (overall and specific types) among newborns of HIV-infected women. Secondary safety outcomes include stillbirths, infant/child death, preterm delivery, overall and specific minor congenital malformations, and small for gestational age infants.

DISCUSSION

Our systematic review will be of utility to healthcare providers, policy-makers, and HIV-positive women regarding the use of antiretroviral drugs.

TRIAL REGISTRATION

PROSPERO registry number: CRD42014009071.

Do antipyretics prevent the recurrence of febrile seizures in children? A systematic review of randomized controlled trials and meta-analysis

OBJECTIVES

To determine the effectiveness of antipyretics use in prevention of subsequent febrile seizures in children.

DATA SOURCES

A search for all available electronic databases (MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, ACP Journal Club, Database of Abstracts of Reviews of Effects (DARE), Cochrane Central Register of Controlled Trials, Cochrane Methodology Register) from 1950 to July 2011 was done. No language restrictions were applied, but English abstract required.

STUDY SELECTION

We included randomized controlled trials comparing the efficacy of antipyretic drugs to placebo in reducing the recurrence rate of febrile seizures in children (6-72 months) with previous febrile seizures. We excluded reviews, letters, and uncontrolled or non-randomized studies.

DATA EXTRACTION AND SYNTHESIS

The literature search was performed by a professional medical librarian. Based of the preliminary search, two reviewers independently pooled studies for detailed manual review per the inclusion criteria. We used the Cochrane Review Manager software (Revman 5) to calculate the odds ratio and 95% confidence intervals (CI) for seizure recurrence, assuming a random-effects model.

RESULTS

Initial search identified 479 citations, five articles underwent further rigorous evaluation by two reviewers and three papers met the inclusion criteria. In these three studies, 540 children were included, of whom 348 received antipyretics (acetaminophen (15 mg/kg), ibuprofen (5-10mg/kg) or diclofenac (1.5mg/kg)) and 192 received placebo for prevention of subsequent febrile seizures during a 1-2 year follow-up period. Seventy-nine patients (22.7%) in the antipyretics group and forty-seven patients (24.4%) in the placebo group had febrile seizure recurrence during follow up. No statistically significant difference was found between the antipyretics and the placebo groups in the recurrence rate of febrile seizures (OR 0.9, 95% CI: 0.57-1.43).

CONCLUSION

Antipyretics were ineffective in reducing the recurrence of febrile seizures.

Rationale and design of the COlchicine for Prevention of the Post-pericardiotomy Syndrome and Post-operative Atrial Fibrillation (COPPS-2 trial): a randomized, placebo-controlled, multicenter study on the use of colchicine for the primary prevention of the postpericardiotomy syndrome, postoperative effusions, and postoperative atrial fibrillation

BACKGROUND

The efficacy and safety of colchicine for the primary prevention of the postpericardiotomy syndrome (PPS), postoperative effusions, and postoperative atrial fibrillation (POAF) remain uncertain. Although preliminary data from a single trial of colchicine given for 1 month postoperatively (COPPS trial) were promising, the results have not been confirmed in a large, multicenter trial. Moreover, in the COPPS trial, colchicine was given 3 days postoperatively.

METHODS

The COPPS-2 study is a multicenter, double-blind, placebo-controlled randomized trial. Forty-eight to 72 hours before planned cardiac surgery, 360 patients, 180 in each treatment arm, will be randomized to receive placebo or colchicine without a loading dose (0.5 mg twice a day for 1 month in patients weighing ≥70 kg and 0.5 mg once for patients weighing <70 kg or intolerant to the highest dose). The primary efficacy end point is the incidence of PPS, postoperative effusions, and POAF at 3 months after surgery. Secondary end points are the incidence of cardiac tamponade or need for pericardiocentesis or thoracentesis, PPS recurrence, disease-related admissions, stroke, and overall mortality.

CONCLUSIONS

The COPPS-2 trial will evaluate the use of colchicine for the primary prevention of PPS, postoperative effusions, and POAF, potentially providing stronger evidence to support the use of preoperative colchicine without a loading dose to prevent several postoperative complications. ClinicalTrials.gov Identifier: NCT01552187.

The Toxicology Investigators Consortium Case Registry--the 2011 experience

In 2010, the American College of Medical Toxicology established its Case Registry, the Toxicology Investigators Consortium (ToxIC). ToxIC is a prospective registry, which exclusively compiles suspected and confirmed toxic exposure cases cared for at the bedside by medical toxicologists at its participating sites. The Registry aims to fulfill two important gaps in the field: a real-time toxicosurveillance system to identify current poisoning trends and a powerful research tool in toxicology. ToxIC allows extraction of information from medical records making it the most robust multicenter database on chemical toxicities in existence. All cases seen by medical toxicologists at participating institutions were entered in a database. Information characterizing patients entered in 2011 was tabulated. 2010 data was also included so that cumulative total numbers could be described as well. The current report is a summary of the data collected in 2011 in comparison to 2010 entries and also includes cumulative data through December 31st, 2011. During 2011, 28 sites with 49 specific institutions contributed a total of 6,456 cases to the Registry. The total number of cases entered into the registry at the end of 2011 was 10,392. Emergency departments remained the most common source of consultations in 2011, accounting for 53 % of cases. The most common reason for consultation was for pharmaceutical overdoses, which occurred in 48 % of patients, including intentional (37 %) and unintentional (11 %) exposures. The most common classes of agents were sedative-hypnotics (1,492 entries in 23 % of cases), non-opioid analgesics (1,368 cases in 21 % of cases), opioids (17 %), antidepressants (16 %), stimulants/sympathomimetics (12 %), and ethanol (8 %). N-acetylcysteine was the most commonly administered antidote during 2011, similar to 2010, followed by the opioid antagonist naloxone, sodium bicarbonate, physostigmine and flumazenil. Anti-crotalid Fab fragments (CroFab) were administered in 106 out of 131 cases in which an envenomation occurred. There were 35 deaths recorded in the Registry during 2011. The most common associated agents, including when reported as sole agent or in combination with other agents, were opioids and analgesics (acetaminophen, aspirin, NSAIDS) with ten and eight deaths, respectively. Oxycodone was reported in six of the ten opioid-related deaths and heroin in three. Acetaminophen was the most common single agent reported overall being identified in all eight of the death cases attributed to analgesics. There were significant trends identified during 2011. Cases involving designer drugs including psychoactive bath salts and synthetic cannabinoids increased substantially from 2010 to 2011. The psychoactive bath salts were responsible for a large increase in stimulant/sympathomimetic-related cases reported to the Registry in 2011 with overall numbers doubling from 6 % of all Registry entries in 2010 to 12 % in 2011. Entries involving psychoactive drugs of abuse also increased twofold from 2010 to 2011 jumping 3 to 6 %, primarily due to increasing frequency of synthetic cannabinoid ("K2") related intoxications as 2011 progressed. The 2011 Registry included over 600 ADR's (10 % of Registry Cases) with 115 agents causing at least 2 ADR's. This is up from only 3 % of cases (116 total cases) in 2010. The ToxIC Case Registry continues to grow. At the end of 2011, over 10,000 cases had been entered into the Registry. As demonstrated by the trends identified in psychoactive bath salt and synthetic cannabinoid reports, the Registry is a valuable toxicosurveillance and research tool. The ToxIC Registry is a unique tool for identifying and characterizing confirmed cases of significant or potential toxicity or complexity to require bedside consultation by a medical toxicologist.

Pharmacokinetic and pharmacogenetic determinants and considerations in chemotherapy selection and dosing in infants

INTRODUCTION

There is a lack of high-quality data regarding optimal chemotherapy dosage regimens among infants. Dosing regimens for chemotherapy during the first year of life are commonly based on empiric recommendations extrapolated from older children; however, balancing efficacy and toxicity is critical as severe adverse drug reactions may lead to treatment failure or reduced adherence to needed medications.

AREAS COVERED

This review describes pharmacokinetic and pharmacogenetic considerations when administering chemotherapeutic agents to infants. Examples of commonly used agents are provided with practical recommendations for dosing adjustments.

EXPERT OPINION

Optimal chemotherapy for children and infants in particular has lagged behind the remarkable progress in cancer treatment and it is clear that far more basic and clinical research are needed with respect to the mechanistic basis of age-dependent differences in pharmacokinetic parameters. More recent studies which have combined pharmacokinetic data with clinical toxicity and outcome data have resulted in a number of more evidence-based guidelines at least for the initial chemotherapy dosing; however, at present, the dosing of chemotherapy drugs in neonates and infants remains largely empiric.

Unfractionated heparin dosing in young infants: clinical outcomes in a cohort monitored with anti-factor Xa levels

BACKGROUND

Unfractionated heparin (UFH) is a widely used anticoagulant. Current American College of Chest Physicians guidelines for infants extrapolated from adults recommend 28 U kg(-1) h(1) of UFH to achieve an anti-factor Xa level of 0.35-0.7 IU mL(-1).

OBJECTIVE

To assess the profile of anti-FXa-based UFH dosing guidelines in infants.

PATIENTS/METHODS

We included all infants aged < 6 months treated with per-protocol intravenous UFH at the Hospital for Sick Children, Toronto, over a 3.5-year period.

RESULTS

Of 100 infants, 11% achieved sustained therapeutic anti-FXa levels with current dose recommendations. Only 15% achieved target anti-FXa levels within 24 h with per-protocol dose escalations. Seventeen per cent of patients never achieved therapeutic anti-FXa levels, despite up to 60 days of therapy and triple the recommended dose. The median dose needed to achieve therapeutic anti-FXa levels in the remaining 83 infants was 33 U kg(-1) h(-1) (interquartile range, 30-36). Two in three infants had decreased thrombus size at completion of therapy and no thrombus progression/recurrence, and 11/100 infants suffered major bleeding. Without exclusion of extracorporeal membrane oxygenation patients, an activated partial thromboplastin time (APTT) of > 180 s was detected as a risk factor for major bleeding.

CONCLUSIONS

UFH monitoring is challenging in infants. Despite their delay in reaching therapeutic anti-FXa levels, infants monitored with the adult-based anti-FXa range have a high thrombus resolution rate, no thrombus progression, but a relatively high bleeding rate. Extreme APTT elevation may contribute to this bleeding risk, particularly in critically ill patients. Current UFH guidelines for young infants may still be inadequate, and laboratory methods with age-appropriate ranges may be required to further improve clinical outcomes within this population.

Outcome following high-dose methotrexate in pregnancies misdiagnosed as ectopic

OBJECTIVE

The objective of this study was to report the outcomes of intrauterine pregnancies misdiagnosed as ectopic and exposed to methotrexate, a major teratogen.

STUDY DESIGN

We report the outcomes of all subjects who sought consultation after exposure to high-dose methotrexate to induce abortion in presumed ectopic pregnancies, which were later identified as viable intrauterine pregnancies by 3 North American Teratology Information Services between 2002 and 2010.

RESULTS

Eight women with normal, desired pregnancies were administered high-dose methotrexate in the first trimester because of presumed, misdiagnosed ectopic pregnancies. All pregnancies resulted in catastrophic outcomes. Two pregnancies resulted in severely malformed newborns with methotrexate embryopathy; 3 women miscarried shortly after exposure, and in 3 the erroneous diagnosis led the physicians to advise and perform surgical termination.

CONCLUSION

Erroneous diagnosis of intrauterine pregnancies as ectopic with subsequent first-trimester exposure to methotrexate may result in the birth of severely malformed babies or fetal demise.

Recurrence and outcomes of Stevens-Johnson syndrome and toxic epidermal necrolysis in children

OBJECTIVES

To report clinical course, etiology, management, and long-term outcomes of children suffering from Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN).

METHODS

We conducted a study of all pediatric patients with SJS or TEN admitted between 2000 and 2007 to the Hospital for Sick Children and Children's Hospital Boston, and particular attention was paid to clinical manifestations, etiology, mortality, and long-term outcomes.

RESULTS

We identified 55 cases of SJS (n = 47), TEN (n = 5), or SJS/TEN overlap syndrome (n = 3). Drugs were identified as the most likely etiologic agent in 29 children (53%); antiepileptic drugs were the most common agents (n = 16), followed by sulfonamide antibiotics (n = 7) and chemotherapy drugs (n = 2). Acute Mycoplasma pneumoniae infection was confirmed in 12 children (22%), and herpes simplex virus was confirmed in 5 children (9%). Treatment regimens differed significantly between participating sites and included systemic antimicrobial agents (67%), systemic corticosteroids (40%), and antiviral drugs (31%). Intravenous immunoglobulin was administered to 21 children (38%), of whom 8 received concomitant systemic corticosteroids. Ten children (18%) had recurrence of SJS up to 7 years after the index episode, and 3 experienced multiple recurrences. Twenty-six children (47%) suffered long-term sequelae that mostly involved the skin and eyes.

CONCLUSIONS

Mortality rate in children was lower than that reported in adults, but half of affected children suffered long-term complications. The recurrence rate of SJS was high (1 in 5), which suggests vulnerability and potential genetic predisposition. In the absence of standardized management guidelines for these conditions, treatment regimens differed significantly between participating institutions.

Palatability, adherence and prescribing patterns of antiretroviral drugs for children with human immunodeficiency virus infection in Canada

PURPOSE

To assess the impact of perceived palatability of antiretroviral drugs on adherence to therapy of children infected by human immunodeficiency virus and on prescribing patterns by their caring physicians.

METHODS

DESIGN

Two arms--retrospective chart review and a cross-sectional survey.

SETTING

Tertiary-care pediatric human immunodeficiency virus clinic during a 17-year period.

PARTICIPANTS

Children with human immunodeficiency virus infection and physicians actively caring for children with human immunodeficiency virus infection in seven provinces in Canada were surveyed regarding their perception of the palatability of 8-liquid and 15 non-liquid antiretroviral medications and its effect on drug selection.

MAIN OUTCOME MEASURE

Effect of taste preferences of antiretroviral drugs on adherence to treatment by infected children and on drug selection by their caring physicians.

RESULTS

Forty of 119 children (34%) refused at least once to an antiretroviral medication. In 5%, treatment was discontinued because of poor palatability. Ritonavir was the least palatable drug (50% of children; p = 0.01). Ritonavir use (OR 4.80 [95%CI 1.34-17.20]) and male gender (OR 7.25 [95%CI 2.30-22.90]) were independent predictors of drug discontinuation because of poor taste. Physicians also perceived liquid ritonavir as the least palatable (p = 0.01) and the most likely to be discontinued (p = 0.01). However, they commonly prescribed it as first-line therapy (p = 0.06).

CONCLUSIONS

A third of children infected with human immunodeficiency virus fail to adhere to their treatment because of poor drug taste. Physicians are aware of that, but this does not prevent them from selecting the least palatable drugs as first-line therapy.

Severe bullous hypersensitivity reactions after exposure to carbamazepine in a Han-Chinese child with a positive HLA-B*1502 and negative in vitro toxicity assays: evidence for different pathophysiological mechanisms

BACKGROUND

Drug hypersensitivity syndrome (DHS) can present in several clinical forms ranging from simple maculopapular skin rash to severe bullous reactions and multi-system dysfunction. Genetic analysis of DHS patients has revealed a striking association between carbamazepine (CBZ)-induced severe bullous reactions, such as Steven-Johnson Syndrome, and toxic epidermal necrolysis in individuals from Southeast Asia who carry a specific HLA allele (HLA-B*1502). This ethnic-specific relationship with a disease phenotype has raised the question of the commonality of the pathogenesis mechanisms of these diseases. The aim of this study was to investigate the genetic and metabolic bases of DHS development to help predict patient susceptibility.

METHOD

A case of carbamazepine-induced Steven-Johnson Syndrome reaction in a HLA-B*1502 positive child of Han Chinese origin, a carbamazepine-induced DHS case in a Caucasian patient and 3 healthy controls were investigated. We performed two types of in vitro toxicity assay, the lymphocyte toxicity assay (LTA) and the novel in vitro platelet toxicity assay (iPTA) on cells taken from the Chinese child 3 and 9 months after recovery from the reaction and from two healthy volunteers. We also tested the Caucasian patient, who developed CBZ-induced DHS, 3 months after the reaction.

RESULTS

Both LTA and iPTA tests were negative 3 and 9 months after the reaction on samples from the Chinese child whereas the tests were positive in the Caucasian patient.

CONCLUSION

These results strongly suggest more than one mechanistic pathway for different CBZ-induced hypersensitivity reactions in patients with different ethnic backgrounds.

Variability in tacrolimus blood levels increases the risk of late rejection and graft loss after solid organ transplantation in older children

  Late graft rejection impairs the long-term function of organ transplants in children. Previous studies suggest patients with wide variation in tacrolimus levels may have higher rates of late kidney and liver graft rejection. The reproducibility of this finding and impact on graft and recipient survival have not been reported. We investigated factors associated with late rejection > 6 months post-transplant in 144 heart, kidney, liver, and lung transplant recipients (ages 8-18, ≥ 1-yr survivors, receiving tacrolimus-based immunosuppression), comparing late rejectors (n = 61, 42%) to non-rejectors (no rejection > 6 months); groups had similar mean tacrolimus concentrations ≤ 6 months post-transplant. For all organ types, increased standard deviation in intrapatient tacrolimus blood levels was an independent risk factor for late rejection (OR 1.6 [CI 1.1-2.1]; p = 0.02). Each 1-point increase in s.d. > 2 of tacrolimus level > 6 months post-transplant associated with 1.58 increase in hazard of graft loss (p = 0.003). Graft survival (conditional on one-yr survival) was significantly better for those with s.d. < 2 at > 6 months post-transplant: 98% at three and five yr, versus 88%, 70%, at three and five yr, in patients with s.d. > 2 (p = 0.003). In conclusion, high s.d. in serial tacrolimus concentrations associated with increased risk of late rejection and graft loss in pediatric organ transplant recipients, providing opportunities for screening and interventions.

Ondansetron dosing in pediatric gastroenteritis: a prospective cohort, dose-response study

BACKGROUND

Ondansetron is increasingly used to prevent emesis in children with acute gastroenteritis; however, the optimal dose is unknown.

OBJECTIVE

To determine if higher doses of oral ondansetron are associated with greater efficacy or side effects.

METHODS

We analyzed data from a prospective clinical trial performed between January 2004 and April 2005. Data were collected on 105 children with dehydration due to gastroenteritis who received an ondansetron oral disintegrating formulation. The following outcomes of efficacy were analyzed: number of vomiting episodes, volume of oral rehydration fluids consumed, percent weight gain, and the proportions of children who had ongoing vomiting, received intravenous rehydration, and were hospitalized. In addition, the number of episodes of diarrhea was evaluated to measure whether there were dose-dependent side effects.

RESULTS

Participants were aged 0.5-8.2 years and the dose ranged between 0.13 and 0.26 mg/kg. There was no significant association between the dose of ondansetron and the outcomes of number of vomiting episodes, volume of fluids consumed, increase in bodyweight, or number of diarrhea episodes/hour. The mean dose of ondansetron (mg/kg) administered was not different amongst those who did and did not have ongoing vomiting, undergo hospitalization, and receive intravenous rehydration.

CONCLUSIONS

Within the dose range of 0.13-0.26 mg/kg, higher doses of ondansetron were not superior to lower doses, nor were they associated with increased side effects. Thus, ondansetron in this dose range was shown to result in a similar reduction in emesis in children with acute gastroenteritis.

Colchicine poisoning: the dark side of an ancient drug

INTRODUCTION

Colchicine is used mainly for the treatment and prevention of gout and for familial Mediterranean fever (FMF). It has a narrow therapeutic index, with no clear-cut distinction between nontoxic, toxic, and lethal doses, causing substantial confusion among clinicians. Although colchicine poisoning is sometimes intentional, unintentional toxicity is common and often associated with a poor outcome.

METHODS

We performed a systematic review by searching OVID MEDLINE between 1966 and January 2010. The search strategy included "colchicine" and "poisoning" or "overdose" or "toxicity" or "intoxication."

TOXICOKINETICS

Colchicine is readily absorbed after oral administration, but undergoes extensive first-pass metabolism. It is widely distributed and binds to intracellular elements. Colchicine is primarily metabolized by the liver, undergoes significant enterohepatic re-circulation, and is also excreted by the kidneys. THERAPEUTIC AND TOXIC DOSES: The usual adult oral doses for FMF is 1.2-2.4 mg/day; in acute gout 1.2 mg/day and for gout prophylaxis 0.5-0.6 mg/day three to four times a week. High fatality rate was reported after acute ingestions exceeding 0.5 mg/kg. The lowest reported lethal doses of oral colchicine are 7-26 mg.

DRUG INTERACTIONS

CYP 3A4 and P-glycoprotein inhibitors, such as clarithromycin, erythromycin, ketoconazole, ciclosporin, and natural grapefruit juice can increase colchicine concentrations. Co-administration with statins may increase the risk of myopathy.

MECHANISMS OF TOXICITY

Colchicine's toxicity is an extension of its mechanism of action - binding to tubulin and disrupting the microtubular network. As a result, affected cells experience impaired protein assembly, decreased endocytosis and exocytosis, altered cell morphology, decreased cellular motility, arrest of mitosis, and interrupted cardiac myocyte conduction and contractility. The culmination of these mechanisms leads to multi-organ dysfunction and failure. REPRODUCTIVE TOXICOLOGY AND LACTATION: Colchicine was not shown to adversely affect reproductive potential in males or females. It crosses the placenta but there is no evidence of fetal toxicity. Colchicine is excreted into breast milk and considered compatible with lactation.

CLINICAL FEATURES

Colchicine poisoning presents in three sequential and usually overlapping phases: 1) 10-24 h after ingestion - gastrointestinal phase mimicking gastroenteritis may be absent after intravenous administration; 2) 24 h to 7 days after ingestion - multi-organ dysfunction. Death results from rapidly progressive multi-organ failure and sepsis. Delayed presentation, pre-existing renal or liver impairment are associated with poor prognosis. 3) Recovery typically occurs within a few weeks of ingestion, and is generally a complete recovery barring complications of the acute illness.

DIAGNOSIS

History of ingestion of tablets, parenteral administration, or consumption of colchicine-containing plants suggest the diagnosis. Colchicine poisoning should be suspected in patients with access to the drug and the typical toxidrome (gastroenteritis, hypotension, lactic acidosis, and prerenal azotemia).

MANAGEMENT

Timely gastrointestinal decontamination should be considered with activated charcoal, and very large, recent (<60 min) ingestions may warrant gastric lavage. Supportive treatments including administration of granulocyte colony-stimulating factor are the mainstay of treatment. Although a specific experimental treatment (Fab fragment antibodies) for colchicine poisoning has been used, it is not commercially available.

CONCLUSION

Although colchicine poisoning is relatively uncommon, it is imperative to recognize its features as it is associated with a high mortality rate when missed.

Pattern of cerebrospinal fluid lactic dehydrogenase during treatment of bacterial meningitis

Bacterial and aseptic meningitis are characterized by distinctive lactic dehydrogenase isoenzyme patterns. No studies have quantified the dynamics of lactic dehydrogenase isoenzyme distribution during treated bacterial meningitis. We used a retrospective case-series design, and reviewed files of all neonates with bacterial meningitis who attended our pediatric tertiary medical center for 8 years period. We identified neonates in whom a repeated lumbar puncture was indicated. Findings of cerebrospinal fluid analysis, including levels of lactic dehydrogenase isoenzymes, were compared with an age-matched reference group. In two patients with meningitis, lumbar puncture with cerebrospinal fluid analysis was repeated because of inadequate response to treatment or initially obscure etiologic pathogens. Both patients had initially low levels of lactic dehydrogenase-1 and lactic dehydrogenase-2 and high levels of lactic dehydrogenase-4 and lactic dehydrogenase-5, similar to other patients with bacterial meningitis. The distribution pattern of lactic dehydrogenase isoenzyme normalized after adequate antibiotic treatment. In light of the encouraging results in these two patients, further studies are warranted regarding the value of lactic dehydrogenase isoenzyme measurements for follow-up purposes and for evaluations of response to treatment.