Decreased Self-reported Physical Fitness Following SARS-CoV-2 Infection and the Impact of Vaccine Boosters in a Cohort Study.

Background: The long-term effects of coronavirus disease 2019 (COVID-19) on physical fitness are unclear, and the impact of vaccination on that relationship is uncertain. Methods: We compared survey responses in a 1-year study of US military service members with (n = 1923) and without (n = 1591) a history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We fit Poisson regression models to estimate the association between history of SARS-CoV-2 infection and fitness impairment, adjusting for time since infection, demographics, and baseline health. Results: The participants in this analysis were primarily young adults aged 18-39 years (75%), and 71.5% were male. Participants with a history of SARS-CoV-2 infection were more likely to report difficulty exercising (38.7% vs 18.4%; P < .01), difficulty performing daily activities (30.4% vs 12.7%; P < .01), and decreased fitness test (FT) scores (42.7% vs 26.2%; P < .01) than those without a history of infection. SARS-CoV-2-infected participants were at higher risk of these outcomes after adjusting for other factors (unvaccinated: exercising: adjusted risk ratio [aRR], 3.99; 95% CI, 3.36-4.73; activities: aRR, 5.02; 95% CI, 4.09-6.16; FT affected: aRR, 2.55; 95% CI, 2.19-2.98). Among SARS-CoV-2-positive participants, full vaccination before infection was associated with a lower risk of post-COVID-19 fitness impairment (fully vaccinated: exercise: aRR, 0.81; 95% CI, 0.70-0.95; activities: aRR, 0.76; 95% CI, 0.64-0.91; FT: aRR, 0.87; 95% CI, 0.76-1.00; boosted: exercise: aRR, 0.62; 95% CI, 0.51-0.74; activities: aRR, 0.52; 95% CI, 0.41-0.65; FT: aRR, 0.59; 95% CI, 0.49-0.70). Conclusions: In this study of generally young, healthy military service members, SARS-CoV-2 infection was associated with lower self-reported fitness and exercise capacity; vaccination and boosting were associated with lower risk of self-reported fitness loss.

Prevalence of Intestinal Parasitic Infections, Genotypes, and Drug Susceptibility of Giardia lamblia among Preschool and School-Aged Children: A Cross-Sectional Study in Thailand.

This study aimed to estimate the prevalence of intestinal parasitic infections in children and assess the drug susceptibility and genotypes/assemblages of Giardia lamblia in Thailand. This cross-sectional study was conducted among children aged 3-12 years in Sangkhlaburi District, Kanchanaburi Province, Thailand, between 25 September 2017 and 12 January 2018. Parasites were identified by stool microscopic examination, cultivation of intestinal parasitic protozoa, and enzyme-linked immunosorbent assay (ELISA). Drug susceptibility and genotype of G. lamblia were performed, respectively, by a resazurin assay and Triosephosphate Isomerase A and B genes using modified primers and probes. Among the 661 participants, 445 had an intestinal parasitic infection, resulting in a prevalence of 67.32% (95% CI: 63.60-70.89%). Blastocystis hominis was the most prevalent protozoa infection (49.32%; 95% CI: 45.44-53.22%), while Ascaris lumbricoides was the most prevalent helminth infection (0.91%; 95% CI: 0.33-1.97%). The prevalence of G. lamblia was 17.40%, with genotype B being the most common. According to our study, intestinal parasitic infections were commonly found in Thai children. G. lamblia was the most common pathogenic protozoa infection identified and exhibited less susceptibility to metronidazole compared to furazolidone and mebendazole.

Factors Associated With Viral Suppression and Drug Resistance in Children and Adolescents Living With HIV in Care and Treatment Programs in Southern Tanzania.

BACKGROUND: Achieving viral suppression (VS) for persons living with HIV is key to reaching epidemic control. We assessed the prevalence of VS and the frequency of HIV drug resistance mutations (HIVDRM) among children and adolescents living with HIV (CALHIV) in the Southern Highland zone of Tanzania. METHODS: From 2019 to 2021, we enrolled CALHIV aged 1-19 years on ART for >6 months in a cross-sectional study. Participants had viral load (VL) testing; those with VL ≥ 1000 copies/mL underwent HIVDRM testing. VS (<1000 copies/mL) prevalence estimates were calculated and robust Poisson regression was used to estimate prevalence ratios (PRs) and 95% confidence intervals (CIs) for associations with potential predictors of VS. RESULTS: Of 707 participants, 595 had VS (PR: 0.84, 95% CI: 0.81-0.87). Use of an integrase strand transfer inhibitor-containing regimen (aPR 1.15, 95% CI: 0.99-1.34), age 5-9 years (aPR 1.16, 95% CI: 1.07-1.26), and seeking care at a referral center (aPR 1.12, 95% CI: 1.04-1.21) were associated with VS. Factors inversely associated with VS included having one (aPR 0.82, 95% CI: 0.72-0.92) or two or more (aPR 0.79, 95% CI: 0.66-0.94) referrals for adherence counselling, and self-reporting missing one to two (aPR 0.88, 95% CI: 0.78-0.99) or three or more (aPR 0.77, 95% CI: 0.63-0.92) doses of ART in the past month. Of 74 participants with PRRT and INT sequencing done, 60 (81.1%) had HIVDRMs at the following frequencies: 71.6%, 67.6%, 1.4%, and 4.1% for major NNRTI, NRTI, PI, and INSTI respectively. CONCLUSIONS: Higher rates of VS were observed in this cohort, and HIVDRMs were common in those without VS. This evidence supports ART optimization using dolutegravir-based regimens. However, better strategies to improve adherence are needed.

Efficacy of drug treatment for severe melioidosis and eradication treatment of melioidosis: A systematic review and network meta-analysis.

BACKGROUND: This systematic review and network meta-analysis (NMA) aimed to compare the efficacy of all available treatments for severe melioidosis in decreasing hospital mortality and to identify eradication therapies with low disease recurrence rates and minimal risk of adverse drug events (AEs). METHODOLOGY: Relevant randomized controlled trials (RCT) were searched from Medline and Scopus databases from their inception until July 31, 2022. RCTs that compared the efficacy between treatment regimens for severe melioidosis or eradication therapy of melioidosis, measured outcomes of in-hospital mortality, disease recurrence, drug discontinuation, or AEs, were included for review. A two-stage NMA with the surface under the cumulative ranking curve (SUCRA) was used to estimate the comparative efficacy of treatment regimens. PRINCIPAL FINDINGS: Fourteen RCTs were included in the review. Ceftazidime plus granulocyte colony-stimulating factor (G-CSF), ceftazidime plus trimethoprim-sulfamethoxazole (TMP-SMX), and cefoperazone-sulbactam plus TMP-SMX had a lower mortality rate than other treatments and were ranked as the top three most appropriate treatments for severe melioidosis with the SUCRA of 79.7%, 66.6%, and 55.7%, respectively. However, these results were not statistically significant. For eradication therapy, treatment with doxycycline monotherapy for 20 weeks was associated with a significantly higher risk of disease recurrence than regimens containing TMP-SMX (i.e.,TMP-SMX for 20 weeks, TMP-SMX plus doxycycline plus chloramphenicol for more than 12 weeks, and TMP-SMX plus doxycycline for more than 12 weeks). According to the SUCRA, TMP-SMX for 20 weeks was ranked as the most efficacious eradication treatment (87.7%) with the lowest chance of drug discontinuation (86.4%), while TMP-SMX for 12 weeks had the lowest risk of AEs (95.6%). CONCLUSION: Our results found a non-significant benefit of ceftazidime plus G-CSF and ceftazidime plus TMP-SMX over other treatments for severe melioidosis. TMP-SMX for 20 weeks was associated with a lower recurrence rate and minimal risk of adverse drug events compared to other eradication treatments. However, the validity of our NMA may be compromised by the limited number of included studies and discrepancies in certain study parameters. Thus, additional well-designed RCTs are needed to improve the therapy of melioidosis.

A machine learning approach identifies distinct early-symptom cluster phenotypes which correlate with hospitalization, failure to return to activities, and prolonged COVID-19 symptoms.

BACKGROUND: Accurate COVID-19 prognosis is a critical aspect of acute and long-term clinical management. We identified discrete clusters of early stage-symptoms which may delineate groups with distinct disease severity phenotypes, including risk of developing long-term symptoms and associated inflammatory profiles. METHODS: 1,273 SARS-CoV-2 positive U.S. Military Health System beneficiaries with quantitative symptom scores (FLU-PRO Plus) were included in this analysis. We employed machine-learning approaches to identify symptom clusters and compared risk of hospitalization, long-term symptoms, as well as peak CRP and IL-6 concentrations. RESULTS: We identified three distinct clusters of participants based on their FLU-PRO Plus symptoms: cluster 1 ("Nasal cluster") is highly correlated with reporting runny/stuffy nose and sneezing, cluster 2 ("Sensory cluster") is highly correlated with loss of smell or taste, and cluster 3 ("Respiratory/Systemic cluster") is highly correlated with the respiratory (cough, trouble breathing, among others) and systemic (body aches, chills, among others) domain symptoms. Participants in the Respiratory/Systemic cluster were twice as likely as those in the Nasal cluster to have been hospitalized, and 1.5 times as likely to report that they had not returned-to-activities, which remained significant after controlling for confounding covariates (P < 0.01). Respiratory/Systemic and Sensory clusters were more likely to have symptoms at six-months post-symptom-onset (P = 0.03). We observed higher peak CRP and IL-6 in the Respiratory/Systemic cluster (P < 0.01). CONCLUSIONS: We identified early symptom profiles potentially associated with hospitalization, return-to-activities, long-term symptoms, and inflammatory profiles. These findings may assist in patient prognosis, including prediction of long COVID risk.

Persistent COVID-19 Symptoms at 6 Months After Onset and the Role of Vaccination Before or After SARS-CoV-2 Infection.

Importance: Understanding the factors associated with post-COVID conditions is important for prevention. Objective: To identify characteristics associated with persistent post-COVID-19 symptoms and to describe post-COVID-19 medical encounters. Design, Setting, and Participants: This cohort study used data from the Epidemiology, Immunology, and Clinical Characteristics of Emerging Infectious Diseases With Pandemic Potential (EPICC) study implemented in the US military health system (MHS); MHS beneficiaries aged 18 years or older who tested positive for SARS-CoV-2 from February 28, 2020, through December 31, 2021, were analyzed, with 1-year follow-up. Exposures: SARS-CoV-2 infection. Main Outcomes and Measures: The outcomes analyzed included survey-reported symptoms through 6 months after SARS-CoV-2 infection and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnosis categories reported in medical records 6 months following SARS-CoV-2 infection vs 3 months before infection. Results: More than half of the 1832 participants in these analyses were aged 18 to 44 years (1226 [66.9%]; mean [SD] age, 40.5 [13.7] years), were male (1118 [61.0%]), were unvaccinated at the time of their infection (1413 [77.1%]), and had no comorbidities (1290 [70.4%]). A total of 728 participants (39.7%) had illness that lasted 28 days or longer (28-89 days: 364 [19.9%]; ≥90 days: 364 [19.9%]). Participants who were unvaccinated prior to infection (risk ratio [RR], 1.39; 95% CI, 1.04-1.85), reported moderate (RR, 1.80; 95% CI, 1.47-2.22) or severe (RR, 2.25; 95% CI, 1.80-2.81) initial illnesses, had more hospitalized days (RR per each day of hospitalization, 1.02; 95% CI, 1.00-1.03), and had a Charlson Comorbidity Index score of 5 or greater (RR, 1.55; 95% CI, 1.01-2.37) were more likely to report 28 or more days of symptoms. Among unvaccinated participants, postinfection vaccination was associated with a 41% lower risk of reporting symptoms at 6 months (RR, 0.59; 95% CI, 0.40-0.89). Participants had higher risk of pulmonary (RR, 2.00; 95% CI, 1.40-2.84), diabetes (RR, 1.46; 95% CI, 1.00-2.13), neurological (RR, 1.29; 95% CI, 1.02-1.64), and mental health-related medical encounters (RR, 1.28; 95% CI, 1.01-1.62) at 6 months after symptom onset than at baseline (before SARS-CoV-2 infection). Conclusions and Relevance: In this cohort study, more severe acute illness, a higher Charlson Comorbidity Index score, and being unvaccinated were associated with a higher risk of reporting COVID-19 symptoms lasting 28 days or more. Participants with COVID-19 were more likely to seek medical care for diabetes, pulmonary, neurological, and mental health-related illness for at least 6 months after onset compared with their pre-COVID baseline health care use patterns. These findings may inform the risk-benefit ratio of COVID-19 vaccination policy.

Antigenic cartography of well-characterized human sera shows SARS-CoV-2 neutralization differences based on infection and vaccination history.

The rapid emergence of SARS-CoV-2 variants challenges vaccination strategies. Here, we collected 201 serum samples from persons with a single infection or multiple vaccine exposures, or both. We measured their neutralization titers against 15 natural variants and 7 variants with engineered spike mutations and analyzed antigenic diversity. Antigenic maps of primary infection sera showed that Omicron sublineages BA.2, BA.4/BA.5, and BA.2.12.1 are distinct from BA.1 and more similar to Beta/Gamma/Mu variants. Three mRNA COVID-19 vaccinations increased neutralization of BA.1 more than BA.4/BA.5 or BA.2.12.1. BA.1 post-vaccination infection elicited higher neutralization titers to all variants than three vaccinations alone, although with less neutralization to BA.2.12.1 and BA.4/BA.5. Those with BA.1 infection after two or three vaccinations had similar neutralization titer magnitude and antigenic recognition. Accounting for antigenic differences among variants when interpreting neutralization titers can aid the understanding of complex patterns in humoral immunity that informs the selection of future COVID-19 vaccine strains.

Comparison of Piperacillin and Tazobactam Pharmacokinetics in Critically Ill Patients with Trauma or with Burn.

Critical illness caused by burn and sepsis is associated with pathophysiologic changes that may result in the alteration of pharmacokinetics (PK) of antibiotics. However, it is unclear if one mechanism of critical illness alters PK more significantly than another. We developed a population PK model for piperacillin and tazobactam (pip-tazo) using data from 19 critically ill patients (14 non-burn trauma and 5 burn) treated in the Military Health System. A two-compartment model best described pip-tazo data. There were no significant differences found in the volume of distribution or clearance of pip-tazo in burn and non-burn patients. Although exploratory in nature, our data suggest that after accounting for creatinine clearance (CrCl), doses would not need to be increased for burn patients compared to trauma patients on consideration of PK alone. However, there is a high reported incidence of augmented renal clearance (ARC) in burn patients and pharmacodynamic (PD) considerations may lead clinicians to choose higher doses. For critically ill patients with normal kidney function, continuous infusions of 13.5-18 g pip-tazo per day are preferable. If ARC is suspected or the most stringent PD targets are desired, then continuous infusions of 31.5 g pip-tazo or higher may be required. This approach may be reasonable provided that therapeutic drug monitoring is enacted to ensure pip-tazo levels are not supra-therapeutic.

Pharmacokinetics, safety and efficacy of intra-articular non-steroidal anti-inflammatory drug injections for the treatment of osteoarthritis: A narrative review.

WHAT IS KNOWN AND OBJECTIVE: Osteoarthritis (OA) is a common cause of joint disease and activity limitation in adults. Common therapies to treat OA-related pain are oral and topical non-steroidal anti-inflammatory drugs (NSAIDs) and intra-articular (IA) corticosteroids. However, prolonged courses of oral NSAIDs are associated with systemic adverse effects and repeat IA corticosteroid injections may cause cartilage degeneration. IA NSAIDs may be an alternative therapy possibly minimizing systemic side effects while maintaining efficacy. Therefore, we sought to summarize the pharmacokinetics, safety and efficacy of IA NSAIDs to help providers make a more informed decision on the use of IA NSAIDs. METHODS: We searched the National Library of Medicine Database with terms "intraarticular and nsaid", yielding 1032 results. Only traditional formulations of NSAIDs were considered for inclusion. Animal studies were included if animals were healthy or if the method of arthritis induction was a reasonable model of osteoarthritis. Human studies were included if humans were healthy or if the primary disease studied was osteoarthritis of a large joint. Of 1032 results, 31 research articles met the inclusion criteria and were summarized in this review. RESULTS AND DISCUSSION: We found that single doses of IA NSAIDs provided far less total systemic and synovial exposure compared to a one week course of oral NSAIDs, but maximum concentrations to the synovium with IA administration were much higher. IA NSAIDs had an excellent safety profile in small animals, large animals and humans, although these injections were associated with non-specific cartilage inflammation in healthy animals. In animal models, IA NSAIDs had similar efficacy to PO NSAIDs in treating OA-related pain. In humans, IA NSAIDs had similar efficacy to PO NSAIDS and IA corticosteroids in treating OA-related pain; however, many trials did not have a placebo control and outcome measures were heterogeneous. WHAT IS NEW AND CONCLUSION: Overall, single doses of IA NSAIDs appear safe and efficacious across animals and humans. The optimal use of IA NSAIDs is still to be determined and further research is needed. However IA NSAIDs may be an additional beneficial therapy to treat OA-related pain. Potential uses may be to augment IA corticosteroids injections, to interrupt multiple IA corticosteroid injections or as an alternative in patients that are high risk for corticosteroid-related adverse events.

Pharmacokinetics of piperacillin and tazobactam in critically Ill patients treated with continuous kidney replacement therapy: A mini-review and population pharmacokinetic analysis.

WHAT IS KNOWN AND OBJECTIVE: Timely and appropriate dosing of antibiotics is essential for the treatment of bacterial sepsis. Critically ill patients treated with continuous kidney replacement therapy (CKRT) often have physiologic derangements that affect pharmacokinetics (PK) of antibiotics and dosing may be challenging. We sought to aggregate previously published piperacillin and tazobactam (pip-tazo) pharmacokinetic data in critically ill patients undergoing CKRT to better understand pharmacokinetics of pip-tazo in this population and better inform dosing. METHODS: The National Library of Medicine Database was searched for original research containing piperacillin or tazobactam clearance (CL) or volume of distribution (V) estimates in patients treated with CKRT. The search yielded 77 articles, of which 26 reported suitable estimates of CL or V. Of the 26 articles, 10 for piperacillin and 8 for tazobactam had complete information suitable for population pharmacokinetic modelling. Also included in the analysis was piperacillin and tazobactam PK data from 4 critically ill patients treated with CKRT in the Military Health System, 2 with burn and 2 without burn. RESULTS AND DISCUSSION: Median and range of literature reported PK parameters for piperacillin (CL 2.76 L/hr, 1.4-7.92 L/hr, V 31.2 L, 16.77-42.27 L) and tazobactam (CL 2.34 L/hr, 0.72-5.2 L/hr, V 36.6 L, 26.2-58.87 L) were highly consistent with population estimates (piperacillin CL 2.7 L/hr, 95%CI 1.99-3.41 L/hr, V 25.83 22.07-29.59 L, tazobactam CL 2.49 L/hr, 95%CI 1.55-3.44, V 30.62 95%CI 23.7-37.54). The proportion of patients meeting pre-defined pharmacodynamic (PD) targets (median 88.7, range 71%-100%) was high despite significant mortality (median 44%, range 35%-60%). High mortality was predicted by baseline severity of illness (median APACHE II score 23, range 21-33.25). Choice of lenient or strict PD targets (ie 100%fT >MIC or 100%fT >4XMIC) had the largest impact on probability of target attainment (PTA), whereas presence or intensity of CKRT had minimal impact on PTA. WHAT IS NEW AND CONCLUSION: Pip-tazo overexposure may be associated with increased mortality, although this is confounded by baseline severity of illness. Achieving adequate pip-tazo exposure is essential; however, risk of harm from overexposure should be considered when choosing a PD target and dose. If lenient PD targets are desired, doses of 2250-3375 mg every 6 h are reasonable for most patients receiving CKRT. However, if a strict PD target is desired, continuous infusion (at least 9000-13500 mg per day) may be required. However, some critically ill CKRT populations may need higher or lower doses and dosing strategies should be tailored to individuals based on all available clinical data including the specific critical care setting.

Prevalence and Correlates of Viral Load Suppression and Human Immunodeficiency Virus (HIV) Drug Resistance Among Children and Adolescents in South Rift Valley and Kisumu, Kenya.

BACKGROUND: Children and adolescents living with HIV (CALHIV) face unique challenges, including poorer treatment outcomes, risk for drug-resistance mutations (HIVDRMs), and limited drug formulations. We estimated viral suppression (VS) prevalence and evaluated predictors of VS and HIVDRMs in Kenya. METHODS: From 2018-2020, CALHIV 1-19 years on antiretroviral therapy (ART) >6 months were enrolled in this cross-sectional study. Participants underwent viral load (VL) testing; those with VL ≥1000 copies/mL had HIVDRM testing. Sociodemographic questionnaires and medical record abstraction were completed. VS prevalence (VL <1000 copies/mL) was estimated; robust Poisson regression models were used to estimate prevalence ratios (PRs) and 95% CIs for associations between potential predictors of VS. RESULTS: Nine hundred and sixty-nine participants were enrolled. VS prevalence was .80 (95% CI: .78-.83). Being on ART >24 months (adjusted PR [aPR]: 1.22; 95% CI: 1.06-1.41), an integrase strand transfer inhibitor-containing regimen (1.13; 1.02-1.26), and attending a level 3 health facility (1.23; 1.11-1.36) were associated with VS. Missing ≥3 doses of ART in the past month (aPR: .73; 95% CI: .58-.92), having a viremic mother with HIV (.72; .53-.98), and having 3-7 (.90; .83-.97), 8-13 (.89; .82-.97), or ≥14 (.84; .77-.92) compared with <2 adherence counseling referrals were inversely associated with VS. A high proportion (n = 119, 81.5%) of unsuppressed participants had evidence of any major HIVDRM. CONCLUSIONS: HIV treatment programs should target interventions for pediatric patients at risk for treatment failure-namely, those with a caregiver with failed VS and those struggling with adherence.

Meropenem pharmacokinetics in critically ill patients with or without burn treated with or without continuous veno-venous haemofiltration.

INTRODUCTION: Severe burn injury involves widespread skin and tissue damage leading to systemic inflammation, hypermetabolism and multi-organ failure. The hypermetabolic phase of burn injury has been associated with increased systemic antibiotic clearance; however, critical illness in the absence of burn may also induce similar physiologic changes. Continuous renal replacement therapy (CRRT) is often implemented in critically ill patients and may also affect antibiotic clearance. Although the pharmacokinetics (PK) of meropenem has been described in both the burn and non-burn critically ill populations, direct comparative data is lacking. METHODS: For this study, we evaluated PK parameters of meropenem from 23 critically ill patients, burn or non-burn, treated with or without continuous veno-venous haemofiltration (CVVH) to determine the contribution of burn and CVVH to the variability of therapeutic meropenem levels. RESULTS: A two-compartment model best described the data and revealed creatinine clearance (CrCl) and total burn surface area (TBSA) as significant covariates on clearance (CL) and peripheral volume of distribution (Vp), respectively. Of interest, non-burn patients on CVVH displayed an overall lower inherent CL as compared to burn patients on CVVH (6.43 vs. 12.85 L/h). Probability of target attainment (PTA) simulations revealed augmented renal clearance (ARC) may necessitate dose adjustments, but TBSA and CVVH would not. CONCLUSIONS: We recommend a standard dose of 1000 mg every 8 hours; however, if ARC is suspected, or the severity of illness requires a more stringent therapeutic target, we recommend a loading dose of 1000-2000 mg infused over 30 minutes to 1 hour followed by continuous infusion (3000-6000 mg over 24 hours), or intermittent infusion of 2000 mg every 8 hours.

Applying Pharmacogenomic Guidelines to Combat Medical Care.

Pharmacogenomics is a pillar of personalized medicine that has the potential to deliver optimized treatment in many medical settings. Military medicine in the deployed setting is unique and therefore warrants separate assessment pertaining to its potential capabilities and impact. Pharmacogenomics for United States Active Duty Service Members medical care in the deployed setting has not, to our knowledge, been previously reviewed. We present potential applications of pharmacogenomics to forward medical care through two comprehensive references for deployed medical care, the Tactical Combat Casualty Care Guidelines (TCCC) and Emergency War Surgery (EWS) fifth edition. All drugs within the deployment manuals, TCCC guidelines and EWS book, were identified and the list was cross-referenced to the Clinical Pharmacogenetics Implementation Consortium guidelines and genes-drugs interactions list as well as the Food and Drug Administration Table of Pharmacogenomics Biomarkers in Drug Labeling. Ten pharmacologic categories were identified, consisting of 15 drugs, along with the classes, aminogylcosides, beta-blockers, and volatile anesthetics. Drugs and pharmacogenomics liabilities were tabulated. Eight specific drugs or classes are expounded upon given the belief of the authors of their potential for impacting future treatment on the battlefield in the setting of prolonged field care. This review outlines several genes with liabilities in the prolonged field care setting and areas that may produce improved care with further study.

Evaluation of Pharmacogenomics Testing of Cytochrome P450 Enzymes in the Military Health System From 2015 to 2020.

Pharmacogenomics (PGx) plays a fundamental role in personalized medicine, providing an evidence-based treatment approach centered on the relationship between genomic variations and their effect on drug metabolism. Cytochrome P450 (CYP450) enzymes are responsible for the metabolism of most clinically prescribed drugs and a major source of variability in drug pharmacokinetics and pharmacodynamics. To assess the prevalence of PGx testing within the Military Health System (MHS), testing of specific CYP450 enzymes was evaluated. Data were retrospectively obtained from the Military Health System Management Analysis and Reporting Tool (M2) database. Patient demographics were identified for each test, along with TRICARE status, military treatment facility, clinic, and National Provider Identifier. A total of 929 patients received 1,833 PGx tests, predominantly composed of active duty/guard service members (N = 460; 49.5%), with highest testing rates in the army (51.5%). An even distribution in testing was observed among gender, with the highest rates in Caucasians (41.7%). Of the CYP enzymes assessed, CYP2C19 and CYP2D6 accounted for 87.8% of all PGx CYP testing. The majority of patients were tested in psychiatry clinics (N = 496; 53.4%) and primary care clinics (N = 233; 25.1%), accounting for 56.4% and 24.8% of all tests, respectively. Testing was found to be provider driven, suggesting a lack of a standardized approach to PGx and its application in patient care within the MHS. We initially recommend targeted education and revising testing labels to be more uniform and informative. Long-term recommendations include establishing pharmacy-driven protocols and point-of-care PGx testing to optimize patient outcomes.

Prescription Patterns and Relationship to Pharmacogenomics Testing in the Military Health System.

INTRODUCTION: Clinical utilization of pharmacogenomics (PGx) testing is highly institutionally dependent, and little information is known about provider practices of PGx testing in the Military Health System (MHS). In this study, we aimed to characterize Clinical Pharmacogenetics Implementation Consortium (CPIC) actionable prescription (Rx) patterns and their temporal relationship with PGx testing in the MHS. METHODS: Using data from the Military Health System Management Analysis and Reporting Tool (M2) database, this retrospective cohort study included all patients receiving at least one PGx test and at least one CPIC actionable Rx from January 2015 to August 2020 (845 patients, 1,471 PGx, 7,725 index CPIC actionable Rxs). Rx patterns and temporal relationships with PGx testing were characterized via descriptive statistics. Binomial regression was used to determine which patient and provider characteristics were associated with a patient receiving a PGx test within 30 days of an index Rx. RESULTS: Patients had a median of 9 index CPIC actionable Rx's (range 1-26). Pain medications were most commonly prescribed (N = 794, 94% patients with at least 1 Rx). However, pain medication had the lowest Rx-PGx match rate (40%) compared to an average of 62% Rx-PGx match rate for all CPIC drugs. Antidepressants were also commonly prescribed (N = 668, 79.1% patients with at least 1 Rx), and antidepressants had the highest Rx-PGx match rate of 86.7%. A minority of providers (20%, N = 249) ordered the majority of PGx tests (86.1%, N = 1,266) and only 8.3% of PGx tests (N = 398) matched to a CPIC actionable drug within 30 days of the test (defined by Rxs ordered within 30 days before or after the PGx test). However, approximately 39.8% of patients (N = 317) had at least one drug match to a PGx test within 30 days. The largest predictor of whether a patient received a PGx test within 30 days of any index Rx was whether or not a specific psychiatry provider ordered the PGx test (odds ratio; OR 3.7, 95% CI 2.13-6.54, P < 0.001). Neither the CPIC level of evidence nor FDA PGx actionable or informative labels had a significant effect on PGx test timing. CONCLUSIONS: PGx testing was generally limited to high Rx-drug users and was found to be an under-utilized resource. PGx testing did not typically follow CPIC guidelines. Implementing PGx testing protocols, simplifying PGx test-ordering by incorporating at minimum CYP2D6, CYP2C19, and CYP2C9 into PGx-testing panels, and unifying providers' PGx knowledgebase in the MHS are feasible and would improve the clinical utilization of PGx tests in the MHS.

Semimechanistic Modeling of the Effects of Blast Overpressure Exposure on Cefazolin Pharmacokinetics in Mice.

Cefazolin is a first-line antibiotic to treat infection related to deployment-associated blast injuries. Prior literature demonstrated a 331% increase cefazolin liver area under the curve (AUC) in mice exposed to a survivable blast compared with controls. We repeated the experiment, validated the findings, and established a semimechanistic two-compartment pharmacokinetic (PK) model with effect compartments representing the liver and skin. We found that blast statistically significantly increased the pseudo-partition coefficient to the liver by 326% (95% confidence interval: 76-737%), which corresponds to the observed 331% increase in cefazolin liver AUC described previously. To a lesser extent, plasma AUC in blasted mice increased 14-45% compared with controls. Nevertheless, the effects of blast on cefazolin PK were transient, normalizing by 10 hours after the dose. It is unclear as to how this blast effect t emporally translates to humans; however, given the short-lived effect on PK, there is insufficient evidence to recommend cefazolin dosing changes based on blast overpressure injury alone. Clinicians should be aware that cefazolin may cause drug-induced liver injury with a single dose and the risk may be higher in patients with blast overpressure injury based on our findings. SIGNIFICANCE STATEMENT: Blast exposure significantly, but transiently, alters cefazolin pharmacokinetics in mice. The questions of whether other medications or potential long-term consequences in humans need further exploration.

Population Pharmacokinetic Modeling and Simulations of Imipenem in Burn Patients With and Without Continuous Venovenous Hemofiltration in the Military Health System.

Continuous venovenous hemofiltration (CVVH) is a life-sustaining procedure in patients with severe burns and acute kidney injury. Physiologic changes from burn injury and use of CVVH may alter imipenem pharmacokinetics (PK). We aimed to compare imipenem clearance (CL) in burn patients with and without CVVH, determine the effect of burn on imipenem volume of distribution (CVVH, n = 12; no CVVH, n = 11), in combination with previously published models. Model qualification was performed with standard diagnostics and comparing predicted PK parameters/time-concentration profiles with those in the existing literature. Monte Carlo simulations were conducted to evaluate the probability of target attainment. A 2-compartment model best described the data. Utilizing albumin as a covariate on volume parameters and leveraging the clearance model from prior literature, our model predicted imipenem central volume and CL within a 10% margin of error across healthy, renally impaired, and burn populations. We provide direct comparison of imipenem CL in burn patients with and without CVVH. Notably, there was no significant difference. Large imipenem Vd in patients with severe burns is likely explained by increased capillary permeability, for which serum albumin may be a reasonable surrogate. Dosing 500 mg every 6 hours is adequate for burn patients on renally dosed CVVH; however, suspicion of augmented renal clearance or patients placed on CVVH without renal impairment may necessitate dosing of 1000 mg every 6 hours.

An open label study of the safety and efficacy of a single dose of weekly chloroquine and azithromycin administered for malaria prophylaxis in healthy adults challenged with 7G8 chloroquine-resistant Plasmodium falciparum in a controlled human malaria infection model.

BACKGROUND: Malaria remains the top infectious disease threat facing the U.S. military in many forward operating environments. Compliance with malaria chemoprophylaxis remains a critical component in preventing malaria in the deployed Service Member. Studies of previous military operations show that compliance is consistently higher with weekly versus daily dosing regimens. Current FDA approved weekly chemoprophylaxis options have contraindications that can limit prescribing. The combination of chloroquine (CQ) with azithromycin (AZ) has previously been shown to be an efficacious treatment option for malaria, has pharmacokinetics compatible with weekly dosing, and has shown synergy when combined in vitro. METHODS: In this open label study, 18 healthy volunteers, aged 18-50 years (inclusive), were randomly assigned to receive either 300 mg CQ or 300 mg CQ and 2 gm azithromycin (CQAZ) of directly observed therapy, weekly for 3 weeks prior to undergoing mosquito bite challenge with chloroquine-resistant Plasmodium falciparum. Volunteers that remained asymptomatic and had no evidence of parasitaemia continued to receive weekly post-exposure chemoprophylaxis for 3 weeks following malaria challenge. The primary endpoint was the number of volunteers that remained asymptomatic and had no evidence of parasitaemia 28 days after the malaria challenge. RESULTS: All 6 (100%) volunteers randomized to the CQ control group became symptomatic with parasitaemia during the 28-day post-challenge period. Only 1/12 (8.3%) of volunteers in the CQAZ group developed symptoms and parasitaemia during the 28-day post-challenge period. However, after chemoprophylaxis was discontinued an additional 6 volunteers developed parasitaemia between days 28-41 after challenge, with 4 of 6 experiencing symptoms. 80% of subjects in the CQAZ group experienced treatment related gastrointestinal adverse events (including 13% that experienced severe nausea) compared to 38% in the CQ group. A comparison of the pharmacokinetics in the CQAZ group demonstrated higher azithromycin Cmax (p = 0.03) and AUC (p = 0.044) levels in those volunteers who never became parasitaemic compared to those who did. CONCLUSION: Given the high rate of side effects and poor efficacy when administered for 3 weeks before and after challenge, the combination of weekly chloroquine and azithromycin is a suboptimal regimen combination for weekly malaria chemoprophylaxis. Trial registration ClinicalTrials.gov NCT03278808.

Risk of type 2 diabetes mellitus by antimuscarinic agents among adult females receiving care in the military health system.

PURPOSE: To explore patterns of antimuscarinic medication as a risk factor for type 2 diabetes mellitus (T2DM). METHODS: This is a retrospective cohort study of females 18 years or older within the Military Health System from 2006 to 2016. Administrative and claims data were used to select patients who initiated therapy with tolterodine, fesoterodine, oxybutynin, darifenacin, solifenacin, or trospium. Patients with no documented history of T2DM were followed for the occurrence of T2DM, the end of the study or loss of eligibility. Rates of T2DM were calculated for the overall population, by duration of therapy and by individual drugs. Crude and adjusted Cox proportional hazards were calculated to assess differences by duration of use and specific muscarinic antagonist. RESULTS: Over 2.6 million antimuscarinic prescriptions were dispensed to 241 829 females (mean age/SD, 62 ± 18 years). Patients exposed to M3 selective antagonists had highest risk of developing T2DM compared to those exposed to nonselective antagonists. Using oxybutynin, a nonselective antagonist as a comparator, adjusted rate ratios of T2DM were 57% (HR 1.57, 95%CI 1.48-1.67) and 29% (HR 1.29, 95%CI 1.24-1.35) significantly higher for darifenacin and solifenacin, respectively (both M3 selective). CONCLUSIONS: We found exposure to M3 selective antagonists darifenacin and solifenacin had the highest risk of developing T2DM compared to nonselective antagonist oxybutynin. This is supported by well described physiologic mechanisms and may allow for more informed prescribing decisions, particularly if minimizing risk of T2DM is a priority.