Diagnosis of manganism and manganese neurotoxicity: A workshop report.

With declining exposures to manganese (Mn) in occupational settings, there is a need for more sensitive exposure assessments and clinical diagnostic criteria for manganism and Mn neurotoxicity. To address this issue, a workshop was held on November 12-13, 2020, with international experts on Mn toxicity. The workshop discussions focused on the history of the diagnostic criteria for manganism, including those developed by the Institut de Recherche Robert-Sauvé en Santé et en Sécurité du Travail (IRSST) in Quebec in 2005 and criteria developed by the Chinese government in 2002 and updated in 2006; the utility of biomarkers of exposure; recent developments in magnetic resonance imaging (MRI) for assessing Mn accumulation in the brain and diagnosing manganism; and potential future applications of metabolomics. The suggestions of the participants for updating manganism diagnostic criteria included the consideration of: i) A history of previous occupational and environmental exposure to Mn; ii) relevant clinical symptoms such as dystonia; iii) MRI imaging to document Mn accumulation in the neural tissues, including the basal ganglia; and iv) criteria for the differential diagnosis of manganism and other neurological conditions. Important research gaps include the characterization of Mn exposure and other co-exposures, exploration of the roles of different brain regions with MRI, understanding the complexity of metal ion transporters involved in Mn homeostasis, and a need for information on other neurotransmitter systems and brain regions underlying the pathophysiology of manganism.

Concomitant use of statins and sodium-glucose co-transporter 2 inhibitors and the risk of myotoxicity reporting: A disproportionality analysis.

AIMS: Recent case reports have suggested that sodium-glucose co-transporter 2 (SGLT2) inhibitors may interact with statins to increase their risk of myotoxicity. We assessed the risk of myotoxicity reporting associated with concomitant use of SGLT2 inhibitors and statins. METHODS: We queried the US Food and Drug Administration Adverse Event Reporting System (FAERS) from 2013 to 2021 for reports including SGLT2 inhibitors, statins or both. We estimated several measures of disproportionate reporting of myopathy and rhabdomyolysis associated with concomitant use of SGLT2 inhibitors and statins: reporting odds ratio (ROR) with 95% confidence interval (CI), Ω shrinkage measure (safety signal if >0) and an extension of the proportional reporting ratio (PRR) (two-criteria set, safety signal if both criteria are met), using the full FAERS dataset as the reference set. In sensitivity analyses, we focussed on specific SGLT2 inhibitor-statin pairs with higher interaction potential (canagliflozin-rosuvastatin, empagliflozin-rosuvastatin) and accounted for stimulated reporting. RESULTS: There were 456 myopathy and 77 rhabdomyolysis reports involving both an SGLT2 inhibitor and a statin. Concomitant use of SGLT2 inhibitors and statins was not associated with an increased risk of myopathy (ROR 0.79, 95% CI 0.70 to 0.89) or rhabdomyolysis (ROR 0.58, 95% CI 0.41 to 0.83) reporting. For both outcomes, the Ω shrinkage measure was negative and only one criterion of the PRR extension was met. SGLT2 inhibitor-statin pairs with higher interaction potential yielded potential signals for rhabdomyolysis; these signals disappeared after accounting for stimulated reporting. CONCLUSION: There was no increased risk of myotoxicity reporting associated with concomitant use of SGLT2 inhibitors and statins or for specific drug pairs.

Safety and effectiveness of NMDA receptor antagonists for depression: A multidisciplinary review.

Ketamine, an anesthetic available since 1970, and esketamine, its newer S-enantiomer, provide a novel approach for the treatment of depression and other psychiatric disorders. At subanesthetic doses, the two drugs, along with their older congener, phencyclidine (PCP), induce a transient, altered mental state by blocking the N-methyl-D-aspartate (NMDA) receptor for glutamate, the primary excitatory neurotransmitter in the mammalian central nervous system. This multidisciplinary review examines the pharmacology/direct effects on consciousness, effectiveness in depression and acute suicidality, and safety of these fast-acting NMDA antagonists. To capture the essence of 60 years of peer-reviewed literature, we used a semi-structured approach to the subtopics, each of which required a different search strategy. We review the evidence for the three primary reported benefits of the two clinical drugs when used for depression: success in difficult-to-treat patients, rapid onset of action within a day, and immediate effects on suicidality. Key safety issues include the evidence-and lack thereof-for the effects of repeatedly inducing this altered mental state, and whether an adequate safety margin exists to rule out the neurotoxic effects seen in animal studies. This review includes evidence from multiple sources that raise substantial questions about both safety and effectiveness of ketamine and esketamine for psychiatric disorders.

Concomitant Ceftriaxone and Intravenous Calcium Therapy in Infants.

OBJECTIVE: To determine if increased mortality could be detected with the administration of ceftriaxone and IV calcium in infants through an analysis of a large repository of electronic health records. METHODS: Patients were split into 3 groups: 1) neonates, 2) infants, and 3) infants <1 year whose age was not specified. Deaths were classified into mutually exclusive categories based on the administration and timing of ceftriaxone and IV calcium. Crude death rates were calculated, and logistic regression modeling was used to calculate adjusted relative odds of death with associated covariates. RESULTS: A total of 259,149 infants were identified. Of 79,038 neonates, the proportion of patients that received ceftriaxone and IV calcium within 48 hours who died was 3.8%, compared with 1.95% (IV calcium), 0.3% (ceftriaxone), 1.54% (IV fluids), and 2.03% (parenteral nutrition). For 102,456 infants, the proportions of deaths were 5.47% (ceftriaxone and IV calcium within 48 hours), 0.45% (IV calcium), 0.15% (ceftriaxone), 0.39% (IV fluids), and 5.5% (parenteral nutrition). Multivariate analysis showed increased odds of death in infants who received ceftriaxone and IV calcium within 48 hours, regardless of age, and propensity score-matched analysis showed a more than 2-fold increased risk for death. CONCLUSIONS: The increased risk for death following ceftriaxone and IV calcium administration was noted not only in neonates, but among older infants as well.

Systemic quinolones and risk of acute liver failure I: Analysis of data from the US FDA adverse event reporting system.

BACKGROUND AND AIM: Quinolones are a potent and globally popular group of antibiotics that are used to treat a wide range of infections. Some case reports have raised concern about their possible association with acute hepatic failure (AHF). Data from the US FDA Adverse Event Reporting System were evaluated for signals of AHF in association with systemically administered quinolone antibiotics. METHODS: AHF reports between 1969 and 2019q2, with a focus on 2010-2019q2, were analyzed. Specifically, AHF reports linked to non-quinolone antibiotics of known hepatotoxicity were compared to reports with non-quinolone, non-hepatotoxic (reference) antibiotics; and AHF reports with quinolones were also compared to reports with the same group of reference antibiotics. Two disproportionality signal detection techniques (proportional reporting ratio, PRR, and empirical Bayes geometric mean, EBGM) were used to assess the AHF signal for both analyses. RESULTS: Only ciprofloxacin showed a marginal and significant AHF signal (PRR: 1.85 [1.21, 2.81]; EBGM: 1.54 [1.06, 1.81]); moxifloxacin, levofloxacin, and ofloxacin showed weak and nonsignificant signals. CONCLUSION: Further pharmacovigilance studies are required to confirm the association between ciprofloxacin and AHF seen in the present analysis.

Risk of Adverse Cardiovascular Events Following a Myocardial Infarction in Patients Receiving Combined Clopidogrel and Proton Pump Inhibitor Treatment: A Nested Case-Control Study.

BACKGROUND: The clinical implications of potential interactions between proton pump inhibitors (PPIs) and clopidogrel have been debated for over a decade. OBJECTIVE: We assessed the association between combined clopidogrel-PPI treatment and the risk of recurrent myocardial infarction (MI) and three secondary outcomes. PATIENTS AND METHODS: A nested case-control study was conducted within Cerner Corporation's Health Facts® database. A retrospective cohort of patients who experienced a first MI and started clopidogrel treatment was created. Within this cohort, patients experiencing a second MI (cases) were matched with up to five controls. Logistic regression was used to estimate adjusted odds ratios (aORs). Findings were compared with those obtained from models with three negative control exposure drugs: H2 receptor antagonists, prasugrel, and ticagrelor. RESULTS: In total, 2890 recurrent MI cases were identified within 12 months following entry into the cohort of clopidogrel users (N = 52,006). aOR for PPI use versus non-use among clopidogrel users was 1.08 [95% confidence interval (CI) 0.95-1.23]. Similar ORs were obtained for secondary endpoints. A positive association between combined use of clopidogrel/PPIs and increased risk of MI was seen in the group aged 80-89 years (aOR 1.26; 95% CI 1.05-1.51). No associations with MI were observed for (1) H2 receptor antagonist use versus non-use among clopidogrel users or (2) PPI use versus non-use among prasugrel users or among ticagrelor users. CONCLUSIONS: Overall, our findings do not support a significant adverse clinical impact of concomitant clopidogrel/PPI use by patients with MI. Nonetheless, investigation of the possible association seen in those aged 80-89 years may be warranted.

Systematic review and meta-analysis of adverse cardiovascular events associated with proton pump inhibitors used alone or in combination with antiplatelet agents.

The potential association between major adverse cardiovascular events (MACE) and concomitant treatment with proton pump inhibitors (PPIs) and clopidogrel has been debated since 2009. Recent reports, however, suggest that PPIs may increase the risk of MACE independently of clopidogrel. This review evaluates epidemiological findings relevant to the association between PPIs, taken alone or concomitantly with antiplatelets, and the risk of MACE. A systematic review and meta-analysis were conducted. Relevant studies were identified from MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials and then screened. Included studies were categorized into three groups: Group A: PPIs versus no PPIs; Group B: combined PPIs and clopidogrel versus clopidogrel alone; Group C: combined PPIs and other drugs versus other drugs. Pooled risk ratios (RRs) were calculated for each outcome of interest in each comparison group. Of the 1667 studies identified, 118 were included in the systematic review, of which 66 were included in the meta-analyses. Among Group A observational studies, RRs for MACE outcomes were statistically significant for some patient populations but not others. Pooled RRs from Group A RCTs were not statistically significant for any outcome. Pooled RRs for Group B observational studies were statistically significant for all-cause mortality and MI, but were diminished in magnitude when pooling was restricted to propensity score matched studies or post hoc analyses of RCTs. Group C studies did not demonstrate an association with MACE. Findings do not consistently support an association between MACE and PPIs when taken alone, or concomitantly with antiplatelets.

Trends in concomitant clopidogrel and proton pump inhibitor treatment among ACS inpatients, 2000-2016.

PURPOSE: The US Food and Drug Administration (FDA) issued three safety announcements between January 2009 and October 2010 warning against concomitant use of clopidogrel and proton pump inhibitors (PPIs) due to a potential drug-drug interaction that may attenuate clopidogrel's antiplatelet activity. This primary objective of this study was to examine trends in concomitant clopidogrel/PPI use among acute coronary syndrome (ACS) inpatients in the US between 2000 and 2016, in relation to the FDA safety communications. METHODS: Adult inpatients with a primary diagnosis of ACS were identified from the Cerner Health Facts® database. The standardized (age, sex, race, and census region) prevalence of clopidogrel use with PPIs was calculated yearly and quarterly. Findings were stratified by PPIs' potential to inhibit clopidogrel's activity and by age. RESULTS: A total of 204,533 inpatients were identified. In 2008, the prevalence of concomitant clopidogrel and PPI treatment was 34.9%, decreasing to 24.4 and 16.4% in 2009 and 2010, respectively, with the decline being similar across age groups. Treatment with inhibiting PPIs (omeprazole and esomeprazole) and clopidogrel has continued to decrease since 2010, with a prevalence of 0.8% in 2016. A similar reduction was not observed with clopidogrel and non-inhibiting PPIs (pantoprazole, lansoprazole, rabeprazole, and dexlansoprazole). During the FDA warning period, the combined treatment with clopidogrel and H2 receptor antagonists, an alternative to PPIs suggested by the FDA, temporarily increased from 7.8% in 2008 to 12.8 and 14.5% in 2009 and 2010, respectively. CONCLUSIONS: Findings suggest that clinical practice recommendations made by the FDA were followed. Further research is needed to determine how changes in drug labels and the availability of new drugs may have influenced the observed trends.

Comparative, cross-sectional study of the format, content and timing of medication safety letters issued in Canada, the USA and the UK.

OBJECTIVES: To assess consistency in the format and content, and overlap of subject and timing, of medication safety letters issued by regulatory health authorities to healthcare providers in Canada, the USA and the UK. DESIGN: A cross-sectional study comparing medication safety letters issued for the purpose of alerting healthcare providers to newly identified medication problems associated with medications already on the market. SETTING: Online databases operated by Health Canada, the US Food and Drug Administration and the UK Medicines and Healthcare products Regulatory Agency were searched to select medication safety letters issued between 1 January 2010 and 31 December 2014. Format, content and timing of each medication safety letter were assessed using an abstraction tool comprising 21 characteristics deemed relevant by consensus of the research team. MAIN OUTCOME MEASURES: Main outcome measures included, first, characteristics (format and content) of medication safety letters and second, overlap of subject and release date across countries. RESULTS: Of 330 medication safety letters identified, 227 dealt with unique issues relating to medications available in all three countries. Of these 227 letters, 21 (9%) medication problems were the subject of letters released in all three countries; 40 (18%) in two countries and 166 (73%) in only one country. Only 13 (62%) of the 21 letters issued in all three countries were released within 6 months of each other. CONCLUSIONS: Significant discrepancies in both the subject and timing of medication safety letters issued by health authorities in three countries (Canada, the USA and the UK) where medical practice is otherwise comparable, raising questions about why, how and when medication problems are identified and communicated to healthcare providers by the authorities. More rapid communication of medication problems and better alignment between authorities could enhance patient safety.

Thiazolidinedione drugs in the treatment of type 2 diabetes mellitus: past, present and future.

Thiazolidinedione (TZD) drugs used in the treatment of type 2 diabetes mellitus (T2DM) have proven effective in improving insulin sensitivity, hyperglycemia, and lipid metabolism. Though well tolerated by some patients, their mechanism of action as ligands of peroxisome proliferator-activated receptors (PPARs) results in the activation of several pathways in addition to those responsible for glycemic control and lipid homeostasis. These pathways, which include those related to inflammation, bone formation, and cell proliferation, may lead to adverse health outcomes. As treatment with TZDs has been associated with adverse hepatic, cardiovascular, osteological, and carcinogenic events in some studies, the role of TZDs in the treatment of T2DM continues to be debated. At the same time, new therapeutic roles for TZDs are being investigated, with new forms and isoforms currently in the pre-clinical phase for use in the prevention and treatment of some cancers, inflammatory diseases, and other conditions. The aims of this review are to provide an overview of the mechanism(s) of action of TZDs, a review of their safety for use in the treatment of T2DM, and a perspective on their current and future therapeutic roles.

External validation and comparison of two variants of the Elixhauser comorbidity measures for all-cause mortality.

Assessing prevalent comorbidities is a common approach in health research for identifying clinical differences between individuals. The objective of this study was to validate and compare the predictive performance of two variants of the Elixhauser comorbidity measures (ECM) for inhospital mortality at index and at 1-year in the Cerner Health Facts® (HF) U.S. DATABASE: We estimated the prevalence of select comorbidities for individuals 18 to 89 years of age who received care at Cerner contributing health facilities between 2002 and 2011 using the AHRQ (version 3.7) and the Quan Enhanced ICD-9-CM ECMs. External validation of the ECMs was assessed with measures of discrimination [c-statistics], calibration [Hosmer-Lemeshow goodness-of-fit test, Brier Score, calibration curves], added predictive ability [Net Reclassification Improvement], and overall model performance [R2]. Of 3,273,298 patients with a mean age of 43.9 years and a female composition of 53.8%, 1.0% died during their index encounter and 1.5% were deceased at 1-year. Calibration measures were equivalent between the two ECMs. Calibration performance was acceptable when predicting inhospital mortality at index, although recalibration is recommended for predicting inhospital mortality at 1 year. Discrimination was marginally better with the Quan ECM compared the AHRQ ECM when predicting inhospital mortality at index (cQuan = 0.887, 95% CI: 0.885-0.889 vs. cAHRQ = 0.880, 95% CI: 0.878-0.882; p < .0001) and at 1-year (cQuan = 0.884, 95% CI: 0.883-0.886 vs. cAHRQ = 0.880, 95% CI: 0.878-0.881, p < .0001). Both the Quan and the AHRQ ECMs demonstrated excellent discrimination for inhospital mortality of all-causes in Cerner Health Facts®, a HIPAA compliant observational research and privacy-protected data warehouse. While differences in discrimination performance between the ECMs were statistically significant, they are not likely clinically meaningful.

The application of PBPK models in estimating human brain tissue manganese concentrations.

Mn is an essential element that causes neurotoxicity in humans when inhaled at high concentrations. This metal has well-recognized route-dependent differences in absorption, with greater proportionate uptake for inhalation versus dietary exposure. Physiologically-based pharmacokinetic (PBPK) models for Mn have included these route specific differences in uptake and their effect on delivery of Mn to target tissues via systemic circulation. These PBPK models include components describing ingestion and inhalation, homeostatic control (concentration dependent biliary elimination and gastrointestinal absorption), and delivery to target sites within the brain. The objective of this study was to combine PBPK modeling of target tissue Mn concentration and categorical regression analysis to identify Mn intake levels (both by food and air) that are expected to cause minimal toxicity. We first used the human PBPK model to describe blood Mn data from three occupational exposure studies, demonstrating consistency between model predictions and measured data. The PBPK model was then used to predict concentrations of Mn in the globus pallidus (the presumed target tissue for motor function disruption in humans) for various epidemiological studies. With the predicted globus pallidus concentration of Mn, we conducted categorical regression modeling between globus pallidus Mn and severity-scored neurological outcome data from the human cohorts. This structured tissue dose - response analysis led to an estimated 10% extra risk concentration (ERC10) of 0.55µg/g Mn in the globus pallidus, which is comparable to similar values estimated by the Agency of Toxic Substances and Disease Registry and Health Canada (after translation from external exposure to tissue dose). The steep dose-response curve below this ERC10 value may be used to inform the choice of adjustment factor to translate the ERC10 as a point of departure to a reference concentration for occupational or environmental exposure to Mn. Because these results are based on human epidemiological data and a human PBPK model, adjustment or translation of results from animals to humans is not required.

Severity scoring of manganese health effects for categorical regression.

Characterizing the U-shaped exposure response relationship for manganese (Mn) is necessary for estimating the risk of adverse health from Mn toxicity due to excess or deficiency. Categorical regression has emerged as a powerful tool for exposure-response analysis because of its ability to synthesize relevant information across multiple studies and species into a single integrated analysis of all relevant data. This paper documents the development of a database on Mn toxicity designed to support the application of categorical regression techniques. Specifically, we describe (i) the conduct of a systematic search of the literature on Mn toxicity to gather data appropriate for dose-response assessment; (ii) the establishment of inclusion/exclusion criteria for data to be included in the categorical regression modeling database; (iii) the development of a categorical severity scoring matrix for Mn health effects to permit the inclusion of diverse health outcomes in a single categorical regression analysis using the severity score as the outcome variable; and (iv) the convening of an international expert panel to both review the severity scoring matrix and assign severity scores to health outcomes observed in studies (including case reports, epidemiological investigations, and in vivo experimental studies) selected for inclusion in the categorical regression database. Exposure information including route, concentration, duration, health endpoint(s), and characteristics of the exposed population was abstracted from included studies and stored in a computerized manganese database (MnDB), providing a comprehensive repository of exposure-response information with the ability to support categorical regression modeling of oral exposure data.

Modeling U-shaped dose-response curves for manganese using categorical regression.

INTRODUCTION: Manganese is an essential nutrient which can cause adverse effects if ingested to excess or in insufficient amounts, leading to a U-shaped exposure-response relationship. Methods have recently been developed to describe such relationships by simultaneously modeling the exposure-response curves for excess and deficiency. These methods incorporate information from studies with diverse adverse health outcomes within the same analysis by assigning severity scores to achieve a common response metric for exposure-response modeling. OBJECTIVE: We aimed to provide an estimate of the optimal dietary intake of manganese to balance adverse effects from deficient or excess intake. METHODS: We undertook a systematic review of the literature from 1930 to 2013 and extracted information on adverse effects from manganese deficiency and excess to create a database on manganese toxicity following oral exposure. Although data were available for seven different species, only the data from rats was sufficiently comprehensive to support analytical modelling. The toxicological outcomes were standardized on an 18-point severity scale, allowing for a common analysis of all available toxicological data. Logistic regression modelling was used to simultaneously estimate the exposure-response profile for dietary deficiency and excess for manganese and generate a U-shaped exposure-response curve for all outcomes. RESULTS: Data were available on the adverse effects of 6113 rats. The nadir of the U-shaped joint response curve occurred at a manganese intake of 2.70mg/kgbw/day with a 95% confidence interval of 2.51-3.02. The extremes of both deficient and excess intake were associated with a 90% probability of some measurable adverse event. CONCLUSION: The manganese database supports estimation of optimal intake based on combining information on adverse effects from systematic review of published experiments. There is a need for more studies on humans. Translation of our results from rats to humans will require adjustment for interspecies differences in sensitivity to manganese.

Demonstration of early efficacy results of the delayed-release combination of doxylamine-pyridoxine for the treatment of nausea and vomiting of pregnancy.

BACKGROUND: Nausea and vomiting of pregnancy (NVP) affects up to 80% of expecting mothers. In April 2013 the FDA approved the delayed-release combination of doxylamine succinate and pyridoxine hydrochloride (Diclegis®) for NVP, based in part, on the results of a phase III randomized trial demonstrating the efficacy of this drug combination [study drug marketed under the trade name Diclectin® in Canada and Diclegis® in the United States] compared to placebo in pregnant women. Study drug dosing occurred for 14 days, which is substantially longer than what has been performed in similar studies. The objective of this study was to evaluate, through secondary analysis, whether the primary measure of efficacy can be demonstrated after five days of treatment. METHODS: Women suffering from NVP were randomized to receive Diclegis® (n = 131) or placebo (n = 125) for 14 days at doses ranging from two to four tablets a day, based on a pre-specified titration protocol. The primary efficacy endpoint was the change in the validated Pregnancy-Unique Quantification of Emesis (PUQE) score at baseline versus Day 15 between Diclegis®-treated and placebo-treated women. For the present study, the change in PUQE score between baseline and Day 15 (end of the study) was compared to the changes observed for Days 3, 4, and 5. RESULTS: The use of delayed-release doxylamine succinate and pyridoxine hydrochloride tablets show improved NVP symptom control as compared to placebo on Days 3,4 and 5, with sustained efficacy until the end of the trial. CONCLUSION: A four day study drug dosing trial with Diclegis® is sufficient to document efficacy, as the results are similar to those achieved after 14 study drug dosing days. The benefit seen at the earlier time validates drug efficacy and minimizes the natural course of improvement. TRIAL REGISTRATION: CTR No. NCT006 14445 2007.

Associations between Anticholinergic Burden and Adverse Health Outcomes in Parkinson Disease.

BACKGROUND: Elderly adults should avoid medications with anticholinergic effects since they may increase the risk of adverse events, including falls, delirium, and cognitive impairment. However, data on anticholinergic burden are limited in subpopulations, such as individuals with Parkinson disease (PD). The objective of this study was to determine whether anticholinergic burden was associated with adverse outcomes in a PD inpatient population. METHODS: Using the Cerner Health Facts® database, we retrospectively examined anticholinergic medication use, diagnoses, and hospital revisits within a cohort of 16,302 PD inpatients admitted to a Cerner hospital between 2000 and 2011. Anticholinergic burden was computed using the Anticholinergic Risk Scale (ARS). Primary outcomes were associations between ARS score and diagnosis of fracture and delirium. Secondary outcomes included associations between ARS score and 30-day hospital revisits. RESULTS: Many individuals (57.8%) were prescribed non-PD medications with moderate to very strong anticholinergic potential. Individuals with the greatest ARS score (≥ 4) were more likely to be diagnosed with fractures (adjusted odds ratio (AOR): 1.56, 95% CI: 1.29-1.88) and delirium (AOR: 1.61, 95% CI: 1.08-2.40) relative to those with no anticholinergic burden. Similarly, inpatients with the greatest ARS score were more likely to visit the emergency department (adjusted hazard ratio (AHR): 1.32, 95% CI: 1.10-1.58) and be readmitted (AHR: 1.16, 95% CI: 1.01-1.33) within 30-days of discharge. CONCLUSIONS: We found a positive association between increased anticholinergic burden and adverse outcomes among individuals with PD. Additional pharmacovigilance studies are needed to better understand risks associated with anticholinergic medication use in PD.