Are 1–2 dangerous? Chloroquine and hydroxychloroquine exposure in toddlers

Systemic lupus erythematosus (SLE) associated uveitis in India - A case series

PURPOSE

To report the uveitic manifestations of patients with systemic lupus erythematosus (SLE).

METHODS

This was a retrospective analysis of all SLE cases with ocular manifestations seen by a single ophthalmologist between 2015 and December 2021.

RESULTS

In total, seven patients with a median age of 40 (range 18-50) years were included in the study. Female (85.7%) predominance was noted. Ocular findings were bilateral in 71% (five patients) of cases. Majority (10 eyes, 83%) of the patients had retinal vasculitis as the common finding. Antinuclear antibodies were positive in all the patients. The vision improved in two (16.6%) eyes, was stable in eight (66%) eyes, and worsened in one (8%) eye. All the patients were treated with oral steroids along with immunosuppressive agents.

CONCLUSION

Though SLE is rare cause of uveitis, it can be associated with significant ocular morbidity. Hence, early diagnosis and treatment can salvage vision in many cases.

Acute Hydroxychloroquine Overdose: A Review of Published Pediatric Cases With Confirmed Hydroxychloroquine Exposure

OBJECTIVES

This review aimed to explore and summarize information from available cases of pediatric acute hydroxychloroquine overdose with confirmed hydroxychloroquine exposure to give the clinicians a helpful perspective for its better recognition and management.

METHODS

Electronic searches were conducted in PubMed/MEDLINE, Web of Science, Scopus, EBSCO and Serbian Citation Index. The abstracts from 2 toxicology conferences were manually checked for additional relevant publications, as well as reference lists of the retrieved publications. Descriptive statistics, narrative summation, and tabulation of the extracted data were made.

RESULTS

Nine publications and a total of 9 patients were included in the review. Reported age of the patients varied from 2.5 to 16 years (median, 16 years). There were more female patients (77.8%). Estimated total ingested hydroxychloroquine dose was reported in 7 cases (77.8%), and it ranged from 4.0 to 20.0 g (median: 12.0 g). Four patients (44.4%) ingested hydroxychloroquine with a coingestant. Altered mental status (100.0%), cardiotoxicity (88.9%), hypotension (77.8%), and hypokalemia (55.6%) were the most commonly reported clinical manifestations. The majority of the patients were hospitalized (88.9%). More than half of the patients (55.6%) were reported to be treated in the intensive care unit. Most frequently reported therapeutic measures were the following: administration of intravenous fluids/infusions (77.8%), vasopressors (77.8%), bicarbonate therapy-sodium bicarbonate (66.7%), potassium replacement (55.6%), and intubation/ventilation (55.6%). Three patients (33.3%) died.

CONCLUSIONS

Management of acute hydroxychloroquine overdose in children should be symptomatic and tailored to observed clinical manifestations. There is a need for additional investigations to better understand the impact and effectiveness of various treatment options.

Massive Nonfatal Hydroxychloroquine Ingestion in a Pediatric Patient

BACKGROUND

Hydroxychloroquine overdose is rare but potentially lethal. Hydroxychloroquine overdose symptoms are characterized by central nervous system toxicity, cardiac toxicity, and hypokalemia. Recommended treatment consists of epinephrine, high-dose diazepam, and careful potassium repletion. Few pediatric hydroxychloroquine overdoses have been reported.

CASE REPORT

We describe a 14-year-old girl who ingested 10 g (172 mg/kg) of hydroxychloroquine. She developed tachycardia, hypotension, and hypokalemia. She was intubated and treated with diazepam and epinephrine infusions and potassium supplementation. Her serum hydroxychloroquine concentration obtained 10 h after ingestion was 13,000 ng/mL (reference range 500-2000 ng/mL). The patient made a full medical recovery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Pediatric hydroxychloroquine overdoses are reported rarely, and the toxic and lethal doses of hydroxychloroquine ingestion have not been established. This case of a teenaged patient who ingested 10 g of hydroxychloroquine and survived provides additional information that may be used to help establish toxic and lethal doses of ingestion.

The utilization of hydroxychloroquine to reduce the main signs and symptoms of COVID-19 patients, a cross-sectional study

Hydroxychloroquine (HCQ) and chloroquine were found to have positive results in some non-randomized clinical trials with more benefit in decreasing the viral load of COVID-19. HCQ is a lysosomotropic and lipophilic drug that can penetrate cell membranes, and accumulates in the acidic lysosomes. The high concentration of alkaline HCQ increases the pH in lysosomes from the normal levels of 4.7-4.8 to 6 which leads to inhibition of lysosomes functions and thus, prevents the entry of coronavirus into cells.

OBJECTIVES

The main aim of this study is to find out the appropriateness of using HCQ in asymptomatic/mildly symptomatic COVID-19 positive patients in an attempt to reduce the development of signs and symptoms of COVID-19 and severe disease.

METHODOLOGY

Randomized selection, open-label trial to evaluate the efficacy of HCQ for patients presenting with asymptomatic COVID-19 upon diagnosis. Cases that met the inclusion criteria were divided into two arms [102 subjects to take HCQ (a loading dose of 400 mg twice daily given orally, followed by a maintenance dose of 200 mg twice daily for 4 days), and 100 subjects were used as a control group]. A follow-up for all the participants on daily basis for 14 days for any signs and symptoms (fever, cough, and shortness of breath). The main variables are action profile (represented by Area under the curve (AUC) for fever, cough, and shortness of breath statistically analyzed to differentiate between the two groups.

RESULTS

Data in this study showed that HCQ was effective in reducing body temperature from the first day to the fifth day; this positive effect was significant with (p < 0.001) compared with subjects who didn't receive HCQ. While there was no significant effect on cough or Shortness of breath.

CONCLUSION

The recommendation of this study is to utilize HCQ to all subjects with asymptomatic COVID-19 infection providing that these subjects are within the inclusion criteria of this study. There was no adverse drug reaction observed for HCQ on daily follow-up.

Presence of "One Pill Can Kill" Medications in Medication Organizers: Implications for Child Safety

BACKGROUND

Medication organizers increased compliance, but they do not contain child protective packaging. Medications organizers have been involved in some pediatric exposures; however, previous reports do not describe if "one pill can kill" (1PCK) medications were involved in the exposures. 1PCK medications may cause toxicity even with a single tablet.

OBJECTIVE

The purpose of this study is to describe the type and presence of 1PCK medications dispensed in medication organizers at a single center.

METHODS

Adult patients who received blister packed medications from September 1, 2017 to September 30, 2017 were included in this retrospective review. Medications were excluded if dispensed traditionally during this time. The primary outcome described included 1PCK medications (quantity and type). Secondary outcomes included total number of tablets dispensed, delayed- (DR) and extended-release (ER) formulations, average age of those dispensed 1PCK medications versus those without.

RESULTS

A total of 450 patients received 486 blister packs and 75.5% of which found to include 1PCK medications. Most commonly included 1PCK medications were beta-blockers and calcium channel blockers (42.4 and 49.4%, respectively). Patients receiving 1PCK medications were older (69.1 ± 12.6 vs 62.6 ± 16.7 years old, p < 0.0001) and included more medications (8.5 ± 2.9 vs 5.7 ± 2.9 medications, p < 0.0001). DR and ER formulations were in 150 packs.

CONCLUSION

The majority of dispensed medication organizers included 1PCK medications. Upon dispensing, patients should be questioned for possible proximity exposures. Additionally, they should receive education on medication safety for children that may be in proximity of the medications during home, work, or social activities.

Coronavirus Disease 2019 (COVID-19) Pharmacologic Treatments for Children: Research Priorities and Approach to Pediatric Studies

Clinical trials of pharmacologic treatments of coronavirus disease 2019 (COVID-19) are being rapidly designed and implemented in adults. Children are often not considered during development of novel treatments for infectious diseases until very late. Although children appear to have a lower risk compared with adults of severe COVID-19 disease, a substantial number of children globally will benefit from pharmacologic treatments. It will be reasonable to extrapolate efficacy of most treatments from adult trials to children. Pediatric trials should focus on characterizing a treatment's pharmacokinetics, optimal dose, and safety across the age spectrum. These trials should use an adaptive design to efficiently add or remove arms in what will be a rapidly evolving treatment landscape, and should involve a large number of sites across the globe in a collaborative effort to facilitate efficient implementation. All stakeholders must commit to equitable access to any effective, safe treatment for children everywhere.

Hydroxychloroquine Toxicity Management: A Literature Review in COVID-19 Era

Background

Hydroxychloroquine (HCQ) has been widely investigated for the treatment of COVID-19. Although it is rare, several case reports of acute toxicity of HCQ due to overdose have been reported during the last two decades. The aim of this review is to summarize the management options of acute HCQ toxicity.

Methods

A literature review that was conducted using an electronic search in the Google Scholar search engine. The inclusion criteria include any patient over 12 years old presenting with HCQ intoxication symptoms from January 1999 to January 2020.

Results

Sixteen cases were found that have the inclusion criteria of this study. Most patients presented with altered mental status, electrocardiogram abnormalities, visual disturbance, and decrease cardiac output. Activated charcoal was the first line of management in nearly two-thirds of patients whereas 93.8% received fluid resuscitation and 81.3% of the patients need at least one type of vasopressor agent. Furthermore, potassium is given for 93.8% of the patient while 75% of the patients need sodium bicarbonate and intubation, lipid emulsion was used in three patients only and 13 patients survived.

Conclusion

The acute HCQ toxicity may result during the treatment period of COVID-19. The most common options can use in this situation include included gastric lavage and decontamination, IV fluid resuscitation, potassium replacement, sodium bicarbonate, intravenous lipid emulsion, and extracorporeal circulation membrane oxygenation. The role of diazepam is not clear but can be used in the significant toxicity while hyperkalemia associated with severe ingestions.

Insights on the Evidence of Cardiotoxicity of Hydroxychloroquine Prior and During COVID-19 Epidemic

The recent empirical use of hydroxychloroquine (HCQ) in coronavirus disease 2019 (COVID-19) revived the interest in its cardiac toxicity, increasingly sidelined over time. We aimed to assess and compare the profile of cardiac adverse drug reactions (CADRs) associated with HCQ before and during COVID-19. We performed a retrospective comparative observational study using the French Pharmacovigilance network database between 1985 and May 2020 to assess all postmarketing CADRs associated with HCQ notified before COVID-19 in its approved indications for lupus and rheumatoid arthritis (preCOV), and those concerning its empirical use in COVID-19 (COV). Eighty-five CADR in preCOV were compared with 141 CADRs in COV. The most common CADR of preCOV were cardiomyopathies (42.4%) and conduction disorders (28.2%), both statistically more frequent than in COV (P < 0.001). COV notifications significantly highlighted repolarization and ventricular rhythm disorders (78.0%, P < 0.001) as well as sinus bradycardias (14.9%, P = 0.01) as compared with preCOV. Estimated incidence of CADR was significantly higher among patients exposed to off-label use of HCQ in COVID-19 (2.9%) than before COVID-19 in its approved indications (0.01%, P < 0.001). The use of HCQ in COVID-19 sheds a new light on the spectrum of its cardiac toxicity. This fosters the value of a closer monitoring of all patients treated with HCQ, regardless of its indication, and the importance of an update of its summary of product characteristics.

Risk assessment of therapeutic agents under consideration to treat COVID-19 in paediatric patients and pregnant women

AIM

Repurposing strategies to address the COVID-19 pandemic have been accelerated. As both pregnant and paediatric patients are likely to be excluded from most planned investigations, the list of repurposed options and the available data on these drugs and vaccines provide a baseline risk assessment and identify gaps for targeted investigation.

METHODS

Clinical trials have been searched and reviewed; 23 repurposed drugs and drug combinations and nine candidate vaccines have been assessed regarding the availability of relevant data in paediatrics and pregnant women and to evaluate expected or unanticipated risk.

RESULTS

Thirteen of the repurposed drugs or drug combinations are indicated for use in paediatrics in some age category albeit for indications other than COVID-19; 10 of these are indicated for use in pregnant women. Even in cases where these drugs are indicated in the populations, source data from which safety and or dosing could be extrapolated for use in COVID-19 is sparse. Vaccine trials are ongoing and generally exclude pregnant women; only in a few instances have paediatric subgroups been planned for enrolment. Data from individual case studies and RWD may suggest that subpopulations of both paediatric patients and pregnant women may be more at risk, particularly those in an increased inflammatory state.

CONCLUSION

In conjunction with more prospective collaboration, plans are evolving to ensure that we will be better prepared to address similar situations especially in paediatrics and pregnant women where experience is limited and actual practice relies heavily on leveraging data from other populations and indications.

Chloroquine dosage regimens in patients with COVID-19: Safety risks and optimization using simulations

Currently no specific medicinal treatment exists against the new SARS-CoV2 and chloroquine is widely used, since it can decrease the length of hospital stay and improve the evolution of the associated COVID-19 pneumonia. However, several safety concerns have been raised from chloroquine use due to the lack of essential information regarding its dosing. The aim of this study is to provide a critical appraisal of the safety information regarding chloroquine treatment and to apply simulation techniques to unveil relationships between the observed serious adverse events and overdosing, as well as to propose optimized dosage regimens. The dose related adverse events of chloroquine are unveiled and maximum tolerated doses and concentration levels are quoted. Among others, treatment with chloroquine can lead to severe adverse effects like prolongation of the QT interval and cardiomyopathy. In case of chloroquine overdosing, conditions similar to those produced by SARS-CoV2, such as pulmonary oedema with respiratory insufficiency and circulatory collapse, can be observed. Co-administration of chloroquine with other drugs for the treatment of COVID-19 patients, like azithromycin, can further increase the risk of QT prolongation and cardiomyopathy. For elder patients there is a high risk for toxicity and dose reduction should be made. This study unveils the risks of some widely used dosing regimens and binds the observed serious adverse events with dosing. Based on simulations, safer alternative dosage regimens are proposed and recommendations regarding chloroquine dosing are made.

COVID-19: Therapeutics and Their Toxicities

SARS-CoV-2 is a novel coronavirus that emerged in 2019 and is causing the COVID-19 pandemic. There is no current standard of care. Clinicians need to be mindful of the toxicity of a wide variety of possibly unfamiliar substances being tested or repurposed to treat COVID-19. The United States Food and Drug Administration (FDA) has provided emergency authorization for the use of chloroquine and hydroxychloroquine. These two medications may precipitate ventricular dysrhythmias, necessitating cardiac and electrolyte monitoring, and in severe cases, treatment with epinephrine and high-doses of diazepam. Recombinant protein therapeutics may cause serum sickness or immune complex deposition. Nucleic acid vaccines may introduce mutations into the human genome. ACE inhibitors and ibuprofen have been suggested to exacerbate the pathogenesis of COVID-19. Here, we review the use, mechanism of action, and toxicity of proposed COVID-19 therapeutics.

Chloroquine, hydroxychloroquine and COVID-19

The media have featured the antimalarials chloroquine (CQ) and hydroxychloroquine (HCQ) to treat coronavirus (COVID-19). Political leaders have touted their use and recommended availability to the public. These anti-inflammatory agents have substantial human toxicity with a narrow therapeutic window. CQ and HCQ poisoning cause myocardial depression and profound hypotension due to vasodilation. Bradycardia and ventricular escape rhythms arise from impaired myocardial automaticity and conductivity due to sodium and potassium channel blockade. With cardiotoxicity, ECGs may show widened QRS, atrioventricular heart block and QT interval prolongation. CQ may also cause seizures, often refractory to standard treatment. Of concern is pediatric poisoning, where 1–2 pills of CQ or HCQ can cause serious and potentially fatal toxicity in a toddler. The treatment of CQ/HCQ poisoning includes high-dose intravenous diazepam postulated to have positive ionotropic and antidysrhythmic properties that may antagonize the cardiotoxic effects of CQ. Infusions of epinephrine titrated to treat unstable hypotension, as well as potassium for severe hypokalemia may be required. Current scientific evidence does not support treatment or prophylactic use of these agents for COVID-19 disease. Regulatory and public health authorities recognize that CQ/HCQ may offer little clinical benefit and only add risk requiring further investigation before wider public distribution.

[Coronavirus: from common cold to severe pulmonary failure]

In December 2019 a new human coronavirus emerged in Wuhan, China, which is known as SARS-CoV‑2. The clinical course of the disease known as coronavirus disease 2019 (COVID-19) ranges from mild respiratory symptoms to severe lung failure. The virus is currently rapidly spreading around the world and pushing health systems to the limits of their capacity due to the exponential increase in the number of cases. The origin of SARS-CoV‑2 lies in the bat coronavirus pool and has now emerged in the human population due to interspecies transmission. Molecular diagnostic methods have been established in a very short time and a number of clinical studies on the effectiveness of different antiviral drugs are ongoing. The development of a vaccine using different approaches is also under investigation.Considering the high number of cases and mortality rates of up to 9% there is an urgent need for action. This article summarizes the current state of knowledge on human coronaviruses with a strong focus on the current data on SARS-CoV‑2. Due to the daily changing level of knowledge, the article reflects the status up to 21 March 2020.

COVID-19 Diagnostic and Management Protocol for Pediatric Patients

This review aims to verify the main epidemiologic, clinical, laboratory-related, and therapeutic aspects of coronavirus disease 2019 (COVID-19) in critically ill pediatric patients. An extensive review of the medical literature on COVID-19 was performed, mainly focusing on the critical care of pediatric patients, considering expert opinions and recent reports related to this new disease. Experts from a large Brazilian public university analyzed all recently published material to produce a report aiming to standardize the care of critically ill children and adolescents. The report emphasizes on the clinical presentations of the disease and ventilatory support in pediatric patients with COVID-19. It establishes a flowchart to guide health practitioners on triaging critical cases. COVID-19 is essentially an unknown clinical condition for the majority of pediatric intensive care professionals. Guidelines developed by experts can help all practitioners standardize their attitudes and improve the treatment of COVID-19.

Diagnostic pitfalls and laboratory test interference after hydroxychloroquine intoxication: A case report

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Hydroxychloroquine overdose can cause hypokalemia.

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Hydroxychloroquine overdose can result in electrocardiographic abnormalities.

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Hydroxychloroquine can interfere with urine chemistry and drug screening assays.

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Urine concentrations of hydroxychloroquine can exceed 500 mg/L in acute overdose.

Hydroxychloroquine is a medication used to treat autoimmune conditions. Overdoses of hydroxychloroquine are uncommon, with most recommendations on monitoring drawing from experience with more common overdoses of the related drug chloroquine. We present a case of an adolescent with intentional overdose of approximately 12 g of hydroxychloroquine. The prominent clinical features were hypokalemia and widened QRS and QT intervals on the electrocardiogram. Therapy included epinephrine by intravenous drip and bicarbonate infusions along with supportive care and cardiac monitoring. The patient recovered without sequelae. Urine drug testing showed an absorbance alarm for one of the components of the institution drug of abuse screening panel, an oxycodone screen using an enzyme immunoassay. Analysis of two urine specimens collected during the hospitalization revealed hydroxychloroquine concentrations of greater than 500 mg/L (approximately 7.5 h after ingestion) and 130 mg/L (approximately 14 h after ingestion). Only the urine with greater than 500 mg/L hydroxychloroquine produced absorbance alarms on the drug of abuse testing. We separately analyzed the impact on 24 urine assays of varying concentrations of hydroxychloroquine spiked into de-identified pooled urine samples. For 6 of the assays (buprenorphine, cotinine, oxycodone, and tetrahydrocannabinol qualitative drug screens; microalbumin and urine myoglobin quantitative assays), hydroxychloroquine produced significant bias and/or instrument alarms. Overall, our study demonstrates that urine concentrations of hydroxychloroquine can reach very high concentrations (exceeding 500 mg/L) following overdose, with the potential to interfere with a range of urine assays including drug of abuse screening and microalbumin. Similar to previous reports, hydroxychloroquine overdose can produce hypokalemia and electrocardiographic abnormalities.

Hydroxychloroquine in children with interstitial (diffuse parenchymal) lung diseases

Hydroxychloroquine (HCQ) is one of the drugs frequently used for the treatment of interstitial lung disease (ILD) in children (chILD). This use is off-label and studies to analyze the effect and safety of HCQ in chILD are lacking. Therefore, a literature research on the usage of chloroquine (CQ) and HCQ in these conditions was done. Eighty-five case reports and small series in the period from 1984 to 2013 were identified in which children with different diagnoses of ILD were treated with CQ or HCQ, sometimes in combination with other medication including steroids. A favorable response to HCQ or CQ was reported in 35 cases, whereas in the other cases the effect was negative or not clear. The dose of HCQ used was between 5 and 10 mg/kg body weight/day (bw/d). No pharmacokinetic studies have been done. The side effect profile in children seemed to be similar to that in adults. Most often gastrointestinal symptoms were reported. Three patients were found developing retinal changes during the treatment with CQ, whereas in none of the patients treated with HCQ retinal changes were reported. Based on retrospective case reports and small series likely to be reported with bias, the use of HCQ in chILD might be classified as safe. As no prospective data on efficacy and safety of HCQ in chILD are available, systematic collection is necessary. This may be achieved by web-based registers like the European Management Platform for Childhood Interstitial Lung Diseases. Prospective and controlled investigations of HCQ in patients with chILD are mandatory.

A phase I/II trial of hydroxychloroquine in conjunction with radiation therapy and concurrent and adjuvant temozolomide in patients with newly diagnosed glioblastoma multiforme

Preclinical studies indicate autophagy inhibition with hydroxychloroquine (HCQ) can augment the efficacy of DNA-damaging therapy. The primary objective of this trial was to determine the maximum tolerated dose (MTD) and efficacy of HCQ in combination with radiation therapy (RT) and temozolomide (TMZ) for newly diagnosed glioblastoma (GB). A 3 + 3 phase I trial design followed by a noncomparative phase II study was conducted in GB patients after initial resection. Patients received HCQ (200 to 800 mg oral daily) with RT and concurrent and adjuvant TMZ. Quantitative electron microscopy and immunoblotting were used to assess changes in autophagic vacuoles (AVs) in peripheral blood mononuclear cells (PBMC). Population pharmacokinetic (PK) modeling enabled PK-pharmacodynamic correlations. Sixteen phase I subjects were evaluable for dose-limiting toxicities. At 800 mg HCQ/d, 3/3 subjects experienced Grade 3 and 4 neutropenia and thrombocytopenia, 1 with sepsis. HCQ 600 mg/d was found to be the MTD in this combination. The phase II cohort (n = 76) had a median survival of 15.6 mos with survival rates at 12, 18, and 24 mo of 70%, 36%, and 25%. PK analysis indicated dose-proportional exposure for HCQ. Significant therapy-associated increases in AV and LC3-II were observed in PBMC and correlated with higher HCQ exposure. These data establish that autophagy inhibition is achievable with HCQ, but dose-limiting toxicity prevented escalation to higher doses of HCQ. At HCQ 600 mg/d, autophagy inhibition was not consistently achieved in patients treated with this regimen, and no significant improvement in overall survival was observed. Therefore, a definitive test of the role of autophagy inhibition in the adjuvant setting for glioma patients awaits the development of lower-toxicity compounds that can achieve more consistent inhibition of autophagy than HCQ.

Hydroxychloroquine: a multifaceted treatment in lupus

The efficacy of antimalarials, especially hydroxychloroquine (HCQ), in preventing systemic lupus erythematosus (SLE) flares is well demonstrated. However, many studies show that the percentage of SLE patients treated with HCQ remains low. By blocking the toll-like receptor 7 and 9 in plasmacytoid dendritic cells, HCQ inhibits interferon-alpha production which plays a crucial role in SLE pathogenesis. In addition to reducing damage accrual in SLE patients, HCQ appears to protect against the occurrence of diabetes, thrombotic events, and dyslipidemia. As a consequence, some studies have suggested that HCQ, which is inexpensive, has a protective effect on survival in SLE patients. Thanks to the pharmacokinetic properties of HCQ (long half-life) and to the availability of its blood assay, very low or undetectable blood HCQ concentrations are a valuable marker of non-adherence to treatment, thus adding a new benefit to HCQ prescriptions. The main side effect of HCQ is retinal toxicity. This complication is very rare, but may be potentially severe, thus requiring regular screening. Retinal toxicity remains the only absolute contra-indication of HCQ in adult SLE patients. Other contra-indications are few and rare. During pregnancy and breast-feeding, HCQ continuation is not only allowed but recommended. In conclusion, the risk/benefit ratio of HCQ is excellent. Many now believe that all SLE patients should be offered this treatment.

Chloroquine is grossly under dosed in young children with malaria: implications for drug resistance

Background

Plasmodium falciparum malaria is treated with 25 mg/kg of chloroquine (CQ) irrespective of age. Theoretically, CQ should be dosed according to body surface area (BSA). The effect of dosing CQ according to BSA has not been determined but doubling the dose per kg doubled the efficacy of CQ in children aged <15 years infected with P. falciparum carrying CQ resistance causing genes typical for Africa. The study aim was to determine the effect of age on CQ concentrations.

Methods and Findings

Day 7 whole blood CQ concentrations were determined in 150 and 302 children treated with 25 and 50 mg/kg, respectively, in previously conducted clinical trials. CQ concentrations normalised for the dose taken in mg/kg of CQ decreased with decreasing age (p<0.001). CQ concentrations normalised for dose taken in mg/m² were unaffected by age. The median CQ concentration in children aged <2 years taking 50 mg/kg and in children aged 10–14 years taking 25 mg/kg were 825 (95% confidence interval [CI] 662–988) and 758 (95% CI 640–876) nmol/l, respectively (p = 0.67). The median CQ concentration in children aged 10–14 taking 50 mg/kg and children aged 0–2 taking 25 mg/kg were 1521 and 549 nmol/l. Adverse events were not age/concentration dependent.

Conclusions

CQ is under-dosed in children and should ideally be dosed according to BSA. Children aged <2 years need approximately double the dose per kg to attain CQ concentrations found in children aged 10–14 years. Clinical trials assessing the efficacy of CQ in Africa are typically performed in children aged <5 years. Thus the efficacy of CQ is typically assessed in children in whom CQ is under dosed. Approximately 3 fold higher drug concentrations can probably be safely given to the youngest children. As CQ resistance is concentration dependent an alternative dosing of CQ may overcome resistance in Africa.

Hepatitis B virus induces IL-23 production in antigen presenting cells and causes liver damage via the IL-23/IL-17 axis

IL-23 regulates myriad processes in the innate and adaptive immune systems, and is a critical mediator of the proinflammatory effects exerted by Th17 cells in many diseases. In this study, we investigated whether and how hepatitis B virus (HBV) causes liver damage directly through the IL-23 signaling pathway. In biopsied liver tissues from HBV-infected patients, expression of both IL-23 and IL-23R was remarkably elevated. In vivo observations also indicated that the main sources of IL-23 were myeloid dendritic cells (mDCs) and macrophages. Analysis of in vitro differentiated immature DCs and macrophages isolated from healthy donors revealed that the HBV surface antigen (HBsAg) efficiently induces IL-23 secretion in a mannose receptor (MR)-dependent manner. Culture with an endosomal acidification inhibitor and the dynamin inhibitor showed that, upon binding to the MR, the HBsAg is taken up by mDCs and macrophages through an endocytosis mechanism. In contrast, although the HBV core antigen (HBcAg) can also stimulate IL-23 secretion from mDCs, the process was MR- and endocytosis-independent. In addition, IL-23 was shown to be indispensible for HBsAg-stimulated differentiation of naïve CD4(+) T cells into Th17 cells, which were determined to be the primary source of IL-17 in HBV-infected livers. The cognate receptor, IL-17R, was found to exist on the hepatic stellate cells and mDCs, both of which might represent the potential target cells of IL-17 in hepatitis B disease. These data provide novel insights into a yet unrecognized mechanism of HBV-induced hepatitis, by which increases in IL-23 expression, through an MR/endocytosis-dependent or -independent manner, produce liver damage through the IL-23/IL-17 axis.

Principles and current strategies for targeting autophagy for cancer treatment

Autophagy is an evolutionarily conserved, intracellular self-defense mechanism in which organelles and proteins are sequestered into autophagic vesicles that are subsequently degraded through fusion with lysosomes. Cells, thereby, prevent the toxic accumulation of damaged or unnecessary components, but also recycle these components to sustain metabolic homoeostasis. Heightened autophagy is a mechanism of resistance for cancer cells faced with metabolic and therapeutic stress, revealing opportunities for exploitation as a therapeutic target in cancer. We summarize recent developments in the field of autophagy and cancer and build upon the results presented at the Cancer Therapy Evaluation Program (CTEP) Early Drug Development meeting in March 2010. Herein, we describe our current understanding of the core components of the autophagy machinery and the functional relevance of autophagy within the tumor microenvironment, and we outline how this knowledge has informed preclinical investigations combining the autophagy inhibitor hydroxychloroquine (HCQ) with chemotherapy, targeted therapy, and immunotherapy. Finally, we describe ongoing clinical trials involving HCQ as a first generation autophagy inhibitor, as well as strategies for the development of novel, more potent, and specific inhibitors of autophagy.

Similar efficacy and tolerability of double-dose chloroquine and artemether-lumefantrine for treatment of Plasmodium falciparum infection in Guinea-Bissau: a randomized trial

BACKGROUND

In 2008, Guinea-Bissau introduced artemether-lumefantrine for treatment of uncomplicated malaria. Previously, 3 times the standard dose of chloroquine, that was probably efficacious against Plasmodium falciparum with the resistance-associated chloroquine-resistance transporter (pfcrt) 76T allele, was routinely used. The present study compared the efficacy and tolerability of a double standard dose of chloroquine with the efficacy and tolerability of artemether-lumefantrine.

METHODS

In a randomized open-label clinical trial, artemether-lumefantrine or chloroquine (50 mg/kg) were given as 6 divided doses over 3 days to children aged 6 months--15 years who had uncomplicated P. falciparum monoinfection. Drug concentrations were measured on day 7. P. falciparum multidrug resistance gene N86Y and pfcrt K76T alleles were identified.

RESULTS

The polymerase chain reaction-adjusted day 28 and 42 treatment efficacies were 162 (97%) of 168 and 155 (97%) of 161, respectively, for artemether-lumefantrine and 150 (95%) of 158 and 138 (94%) of 148, respectively, for chloroquine. When parasites with resistance-associated pfcrt 76T were treated, the day 28 efficacy of chloroquine was 87%. No severe drug-related adverse events were detected. Symptom resolution was similar with both treatments.

CONCLUSIONS

Both treatments achieved the World Health Organization-recommended efficacy for antimalarials that will be adopted as policy. High-dose chloroquine treatment regimes should be further evaluated with the aim of assessing chloroquine as a potential partner drug to artemisinin derivatives. Clinical trials registration. NCT00426439.

Chloroquine is grossly overdosed and overused but well tolerated in Guinea-bissau

High chloroquine doses are commonly prescribed in Guinea-Bissau. Double-dose chloroquine has been shown to be more efficacious (92% efficacy) than the standard dose (80% efficacy). However, chloroquine is toxic when overdosed, and it was not known if the high doses prescribed in Guinea-Bissau were taken or whether they caused adverse effects. We aimed to determine the dosage of chloroquine commonly prescribed, the doses commonly taken, and whether concentration-dependent adverse events occurred in routine practice. Chloroquine prescriptions by eight physicians and chloroquine intake by 102 children were recorded. Chloroquine intake and adverse events were assessed by questioning. Chloroquine concentrations in whole blood were measured. The median total chloroquine dose prescribed and that reportedly taken were 81 and 77 mg kg(-1), respectively. The total dose was usually split into two to three daily doses of 6.6 mg kg(-1) each. These were taken unsupervised for a median of 5 days. Forty percent of the study children had chloroquine concentrations in the same range as those found in a previous study in which double the normal dose (50 mg kg(-1)) of chloroquine was taken. Only 3/102 children had Plasmodium falciparum in the blood at the time of diagnosis and treatment. No severe adverse events were reported. No adverse events were associated with higher chloroquine concentrations. High doses of chloroquine are commonly taken and well tolerated in Guinea-Bissau. Malaria diagnostics are poor, and chloroquine is commonly prescribed to children without parasitemia. Use of high-dose chloroquine is concurrent with an exceptionally low prevalence of chloroquine-resistant P. falciparum.

Carriers, channels and chloroquine efficacy in Guinea-Bissau

Recent studies suggest that chloroquine resistance is mediated by an energy-dependent saturable chloroquine efflux carrier. An alternative explanation is that resistance is mediated by a channel. In Guinea-Bissau high doses of chloroquine are effective, well-tolerated and commonly used. This suggests that chloroquine resistance can be overcome by higher doses. Research on the mechanism of chloroquine resistance is of utmost importance and should include the effect of higher doses.

Pediatric Toxicology

Pediatric patients present unique concerns in the field of medical toxicology. First, there are medicines that are potentially dangerous to small children, even when they are exposed to very small amounts. Clinicians should be wary of these drugs even when young patients present with accidental ingestions of apparently insignificant amounts. Next, over-the-counter laxatives and syrup of ipecac, although not commonly considered abused substances, may be misused in both the setting of Munchausen's syndrome by proxy and in adolescents who have eating disorders. Their use should be considered in any gastrointestinal illness of uncertain origin. Finally, as the use of syrup of ipecac at home now has been discouraged by many, some have explored using activated charcoal at home as a new method of prehospital gastrointestinal decontamination. The literature examining activated charcoal and its use in this capacity is discussed.

Toxicology case of the month: ingestion of two unidentified tablets by a toddler

An asymptomatic 18 month old child presents to the emergency department of a small district hospital shortly after ingesting two unidentified tablets. A small number of pharmaceuticals and illicit drugs may produce life threatening toxicity in a small child if ingested even in one or two dose units and the onset of toxicity may be delayed for some agents. Following risk assessment, a rational management plan is devised and the child is carefully monitored. The patient is observed overnight and discharged home the following day.

One pill can kill: assessing the potential for fatal poisonings in children

Antimalarials, camphor, clonidine, methyl salicylates, and sulfonylureas all may result in serious poisonings and are potentially fatal in small doses in toddlers. Early recognition and appropriate management, including antidotal and supportive care, may prevent poor outcomes in these patients.