About

Dr. Christopher R. Frei is the Division Head of Pharmacotherapy and a Professor of Pharmacotherapy and Translational Sciences at the University of Texas at Austin College of Pharmacy. He also serves as the William J. Sheffield Centennial Endowed Professor and is the Program Director for the Translational Science PhD Program, which involves multiple UT institutions and trains professionals from various health disciplines to conduct clinical and translational research. His research laboratory focuses on building and analyzing large patient cohorts using national Veterans Affairs data repositories and conducting prospective clinical and translational studies in medical practices. Dr. Frei's independent and collaborative research has been supported by agencies such as AHRQ, NIH, and PCORI, as well as universities, professional societies, and the pharmaceutical industry. He has published extensively in leading journals and has given numerous scientific and educational presentations. His work includes evaluating antibiotic pharmacokinetics and pharmacodynamics, revising clinical microbiology standards, and improving antimicrobial dosing strategies to enhance patient outcomes. Additionally, he studies health outcomes and comparative-effectiveness research using national data, identifying patterns in medication use, disease trends, and economic impacts. He has led community-based participatory research efforts to improve treatment of MRSA skin and soft tissue infections, developing practice interventions and innovative diagnostic tools. Dr. Frei is recognized for his mentorship, receiving awards such as 'Mentor of the Year' and 'Young Investigator of the Year,' and holds certifications as a Board Certified Pharmacotherapy Specialist and a Fellow of the American College of Clinical Pharmacy.

Research topics

• Intensive care medicine
• Pharmacology
• Biology
• Microbiology
• Bioinformatics
• Medicine

Selected publications

• 297. Evaluation of Oral Versus Intravenous Beta Lactams for the Treatment of Osteomyelitis

  Open Forum Infectious Diseases · 2026-01-01

  articleOpen access

  Abstract Background Limited data exist regarding the use of oral beta-lactams for the treatment of osteomyelitis (OM). This study evaluated the effectiveness of oral versus intravenous (IV) beta-lactams for the treatment of OM. Methods We conducted a multicenter, retrospective, cohort study of Veterans Affairs (VA) patients who received either oral or IV beta-lactams for the treatment of OM between January 1, 2017 and December 31, 2023. The primary outcome was treatment failure within one year from first dose of definitive therapy, defined as the need to restart or change antimicrobial therapy, additional surgical intervention at the same site, readmission for OM at the same site, or all-cause mortality. Secondary outcomes included hospital length of stay, significant adverse drug events, and frequency of line complications in patients receiving IV therapy. Patients were matched based on BMI > 30 kg/m2, A1c > 8%, and baseline surgical amputation. Chi-square, Fischer’s Exact, and Wilcoxon Rank Sum tests were used to compare outcomes. Multivariate logistic regression models assessed associations between treatment route and outcomes, adjusting for significantly different baseline characteristics. Results Data from 160 patients were included for analysis (80 in each group). Table 1 depicts baseline characteristics. No statistically significant difference was observed in treatment failure between oral and IV beta-lactams (50% vs 45%; p=0.53). All-cause mortality was higher in the oral group (26% vs 6%; < 0.01), while IV-treated patients required more therapy modifications (6% vs 20%; p < 0.01), additional surgeries (15% vs 30%; p=0.03), and readmissions related to OM (14% vs 38%; p < 0.01). Route was not independently predictive of treatment failure (0.53) or overall mortality (p=0.27) in multivariate logistic regression models. No significant differences were observed in secondary outcomes, including hospital length of stay, significant adverse drug events, or line-related complications. Conclusion Oral beta-lactams may be a viable OM treatment option. Higher mortality observed in the oral group likely reflected more patients in hospice or preferring less aggressive care. Future analyses will refine the matching methodology to further balance baseline characteristics. Disclosures All Authors: No reported disclosures

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• P-1678. Gram-Negative Rod Bacteremia due to Organisms not Detected on the BioFire® Blood Culture Identification 2 (BCID2) Panel: Time to Effective Antimicrobial Therapy

  Open Forum Infectious Diseases · 2026-01-01

  articleOpen accessSenior author

  Abstract Background The BioFire® BCID2 panel has revolutionized rapid diagnostics, reducing time to organism identification and targeted therapy. Despite detectability of 16 additional organisms and resistance genes compared to the original panel, limited data exists regarding the clinical impact of BCID-2 negative Gram-Negative Rod (GNR) bacteremia cases. Methods We evaluated the effect of BCID2-negative GNR bacteremia on time to effective therapy (TTET). Overall, 135 patients had BCID2-negative GNR bacteremia from July 2020 to August 2024. Further analysis examined the distribution of BCID-2 negative GNR pathogens and compared clinical outcomes between aerobic and anaerobic cases. Descriptive statistics were used to summarize patient characteristics. Chi-square and Wilcoxon Rank Sum tests were used to compare health outcomes. P-values were statistically significant if they were less than a pre-specified alpha level of 0.05. Results At 12 hours post-BCID2 result, 24% (32/135) of patients lacked effective therapy. This group consisted of 15 aerobes and 17 anaerobes, with a median (interquartile range) TTET of 41 (20-51) hours. A 20-hour increase in median TTET was observed in the aerobic group vs. the anaerobic group: 47 (39-59) vs. 27 (18-42), p=0.02. Aerobes not on effective therapy were led by Pseudomonas putida (13%), Achromobacter spp. (13%), Brucella anthropi (13%), and Myroides spp. (13%). Despite these findings, a 7-day increase in median hospital length of stay (LOS) was observed among anaerobes: (17 (10-34) vs. 10 (7-19) days, p=0.01), with Bacteroides thetaiotaomicron (n=23) and Fusobacterium spp. (n=27) accounting for 60% (50/83) of the anaerobic pathogens. Conclusion These findings indicate that nearly 1 in 4 patients lacked effective therapy 12 hours after a negative BCID2 result. Over half of these cases involved anaerobic pathogens, particularly Bacteroides thetaiotaomicron and Fusobacterium spp., which were associated with a prolonged hospital LOS. Disclosures Christopher R. Frei, PharmD, FCCP, BCPS, Amgen: Grant/Research Support|AstraZeneca: Grant/Research Support

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• Association between sleep duration and fluid biomarkers of Alzheimer's disease: A systematic review

  Sleep Medicine Reviews · 2026-01-23 · 1 citations

  article
  PublisherDOI

• Non‐linear associations between sleep duration and plasma p‐tau181 in the Framingham Heart Study

  Alzheimer s & Dementia · 2026-05-01

  article

  INTRODUCTION: Both short and long sleep duration have been associated with Alzheimer's disease (AD) risk, yet the nature of the non-linear associations between sleep quantity and blood-based biomarkers of AD and neurodegeneration remains understudied. METHODS: Among 2410 Framingham Heart Study participants (mean age: 70.0 ± 8.45 years; 55.2% female), we examined associations between self-reported sleep duration and plasma phosphorylated tau (p-tau)181, total tau, neurofilament light chain, and glial fibrillary acidic protein using restricted cubic splines (RCS) and categorical comparisons (≤ 6, > 6-< 9 reference; ≥ 9 hours). RESULTS: RCS revealed non-linear associations between sleep duration and p-tau181 (overall p = 0.005; non-linearity p = 0.002), with higher levels at ≥ 8.5 hours, after adjusting for age, sex, apolipoprotein E ε4 genotype, sleep apnea, depression, and kidney function. Categorical comparisons showed no association in adjusted models. DISCUSSION: Sleep duration exhibits robust non-linear associations with p-tau181. Findings underscore the importance of non-linear modeling in relating sleep to blood-based biomarkers. Longitudinal studies are needed to clarify temporal relationships and mechanistic pathways.

  PublisherDOI

• Pathoadapative Genomic Determinants of Staphylococcus aureus Community Skin Infections and Nasal Colonization

  Microorganisms · 2025-08-29

  articleOpen access

  Staphylococcus aureus is a leading cause of skin and soft tissue infections (SSTIs), yet the bacterial genomic adaptations underlying the transition from nasal colonization to invasive infection remain incompletely defined. We sequenced and analyzed 157 S. aureus isolates (126 from SSTIs and 31 from asymptomatic nasal colonization) from a primary care network in South Texas. Using genome-wide association studies, non-synonymous single-nucleotide variant (NSNV) profiling, and machine learning, we identified strain-specific adaptations in metabolic and regulatory pathways. SSTI isolates exhibited significant enrichment of nitrogen assimilation, purine biosynthesis, menaquinone production, and anaerobic respiration genes. Elevated copy number and colocalization of phage-linked metabolic genes—including nirB, narH, and nifR3—suggest a pathoadaptive genomic island supporting infection-specific energy generation. The enrichment of α/β-hydrolase domain-encoding genes was associated with clinical severity. To quantify severity, we developed the Purulent Ulcer Skin (PUS) score, which integrates wound size, drainage, and erythema. The α/β-hydrolase and lipoprotein genes were significantly associated with higher PUS scores (higher SSTI severity) and phage-encoded virulence gene products were linked to larger wound size. Machine learning prioritized purL and other metabolic loci as key infection classifiers. NSNVs and unitig-level changes co-localized within nutrient transport, stress resistance, and cytolytic genes, supporting a model of multi-layered genomic selection. Metagenomic assemblies of nasal microbiota were enriched for Staphylococcus, Enterococcus, and Micrococcus species, core metabolic pathways, and taxon-specific virulence determinants. This underscores the roles of metabolic and virulent co-networks within nasal commensals and their adaptive capacity for pathogenic transition. These findings provide a potential genomic blueprint of S. aureus pathoadaptation during SSTI and are a step towards the development of novel therapeutic targets.

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• The Impact of Uncontrolled Gout on Healthcare Utilization and Health Outcomes for United States Veterans Affairs Patients

  Rheumatology and Therapy · 2025-09-19

  articleOpen accessSenior author

  INTRODUCTION: Gout is an inflammatory arthritis that, when uncontrolled, can lead to chronic pain, disability, increased demand for healthcare, and poor health outcomes. This study sought to identify patients with gout and to describe the differences in epidemiology, pharmacotherapy, healthcare utilization, and outcomes for patients with controlled and uncontrolled gout in the United States (US) Veterans Affairs (VA) healthcare system. METHODS: This retrospective cohort study used electronic health record (EHR) data from VA patients from all US states and territories with gout from 1/1/2016 to 12/31/2022. The study included adult VA patients (18 +) with a diagnosis code for gout (ICD10 codes M10 or M1A) and two or more encounters 30 or more days apart. Uncontrolled gout was defined as one serum uric acid level (sUA) level > 8 mg/dl, tophi, or both in the study period. RESULTS: Of the 331,664 patients who met study criteria, 42% (138,068) were considered to have uncontrolled gout and 58% (193,596) were controlled. The uncontrolled group was younger (mean age 64 vs. 70 years, p < 0.01), and both groups were predominantly white non-Hispanic (58% and 70%) and male (99% and 99%). Specialist visits were more common in the uncontrolled group during follow-up: podiatry (38% vs. 30%, p < 0.01), rheumatology (24% vs. 9%, p < 0.01), and nephrology (24% vs. 12%, p < 0.01). Patients with uncontrolled gout were also significantly more likely to be seen in the emergency room (55% vs. 38%, p < 0.01) or admitted to the hospital (47% vs. 37%, p < 0.01) during follow-up. CONCLUSIONS: Nearly half of VA patients with gout met criteria for uncontrolled gout, and these patients experienced greater healthcare utilization and worse health outcomes than patients with controlled gout. Patients with uncontrolled gout could benefit from additional/alternative approaches such as the adoption of a treat-to-target strategy and increasing referrals to a specialist.

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• A comparison of diltiazem versus metoprolol for patients with atrial fibrillation presenting to the emergency department with rapid ventricular rate

  JAPhA Practice Innovations · 2025-02-01

  articleOpen accessSenior author

  <h2>Abstract</h2><h3>Background</h3> Atrial fibrillation (AF) is one of the most common cardiac dysrhythmias and one of the most commonly encountered dysrhythmias in emergency departments (EDs). Rate control is vital to relieve symptoms and prevent complications in patients who present with AF and a rapid ventricular rate (RVR), defined as a heart rate (HR) > 120 beats per minute (bpm). Both metoprolol and diltiazem are recommended for the management of RVR in AF; however, the comparative effectiveness of these medications is unclear. <h3>Objectives</h3> The primary objective of this quality improvement project was to evaluate the achievement of rate control, defined as a HR < 110 bpm or an HR reduction > 20%, within 30 minutes of the first dose of IV diltiazem or metoprolol. The secondary objectives were rate control within 60 minutes of the first dose, rate control within 180 minutes of the first dose, occurrence of repeat dosing, additional medications required for rate control, worsening heart failure (HF) symptoms, admission and discharge diagnoses, hospital readmission within 7 days of discharge, and length of hospital stay. We also assessed the incidence of hypotensive and bradycardic events within 60 minutes of the first dose. <h3>Methods</h3> A total of 571 patient charts were screened for inclusion in this quality improvement project and 151 patients were included. <h3>Results</h3> In a multivariate logistic regression model, with controls for patient age, rate control within 180 minutes of the first dose, and repeat dosing of medication given, there was no statistically significant difference in the primary outcome of rate control within 30 minutes between IV diltiazem (77%) and metoprolol (65%) (odds ratio 0.56 [95% CI 0.22-1.39], <i>P</i> = 0.27). We also found no statistically significant differences in the multivariate models for the incidence of worsening HF, hypotension, or bradycardia. Minimal adverse effects were observed. <h3>Conclusions</h3> The results of this study expand upon previous literature that suggested that diltiazem is likely to be safe and effective in the acute management of AF with RVR, given that there was no statistically significant difference between the 2 study drugs in the achievement of rate control or documentation of worsening HF.

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• Comparison of h-index and other bibliometrics in Google Scholar and Scopus for articles published by translational science trainees

  Humanities and Social Sciences Communications · 2025-02-07 · 4 citations

  articleOpen accessSenior author

  Bibliometrics can help program directors to conduct objective and fair assessments of scholar impact, progress, and collaboration, as well as benchmark performance against peers and programs. However, different academic search engines use different methodologies to provide bibliometric information, so intermixing results from multiple search engines might contribute to inequitable decision-making. Google Scholar and Scopus provide useful bibliometric information for scholars, including the h-index; however, a search of the literature revealed h-index was higher in Google Scholar than Scopus in other scholar populations; therefore, we hypothesized that h-index might also be higher in Google Scholar than Scopus for translational science (TS) trainees. Trained investigators gathered scholarly profile information from Google Scholar and Scopus for all trainees from NIH-supported TS PhD and TS Training (TST) Programs for predoctoral and postdoctoral trainees. Investigators calculated number of citations/year and m-quotient using the data contained therein. M-quotient was defined as h-index divided by "n," where "n" equaled the number of years since first publication. Investigators used the Wilcoxon Signed Rank test to compare bibliometrics (citations, citations/year, h-index, and m-quotient) from both sources for TS students and trainees. A total of 38 trainees (13 TS PhD students and 26 TST trainees) had active profiles in both Google Scholar and Scopus. Of the TST trainees, 21 were predoctoral and five were postdoctoral trainees. All four metrics (citations, citations/year, h-index, and m-quotient) were significantly higher (p<0.05) in Google Scholar than Scopus for the entire study population, TS PhD students, TST trainees, and TST predoctoral trainees. All four bibliometrics were numerically higher (but not significantly higher) in Google Scholar than Scopus for TST postdoctoral trainees as well. This is the first study to compare bibliometrics in Google Scholar and Scopus among translational science trainees. We discovered higher overall citation counts in Google Scholar. Significant differences between Google Scholar and SCOPUS in bibliometrics, such as h-index, could impact the decisions made by program directors if the results are intermixed. Stakeholders should be consistent in their choice of academic search engine and avoid cross engine comparisons, as failure to do so might contribute to inequitable decision-making.

  PublisherDOI

• Guideline-directed medical therapy use in unfunded patients with heart failure with reduced ejection fraction within an academic health system

  American Journal of Pharmacotherapy and Pharmaceutical Sciences · 2025-05-05

  articleOpen access

  Objectives Heart failure (HF) remains a major cause of hospitalizations and mortality globally, despite advances in therapeutics. Quadruple therapy is the foundation for guideline-directed medical therapy (GDMT) of HF with reduced ejection fraction (HFrEF). Despite proven benefits, proper GDMT in everyday practice is underutilized. The purpose of this study is to evaluate outpatient prescribing patterns of GDMT in unfunded HFrEF patients and its impact on clinical outcomes within a large county health system. Materials and Methods A retrospective chart review was conducted for unfunded adult outpatients with a visit diagnosis of HFrEF based on an echocardiogram. Information collected for each study subject included rates of prescribed GDMT, target doses achieved, adherence, pharmacist involvement in dose titration, and hospitalizations/mortality. Results Of the 3219 patients with a chart diagnosis of HFrEF, 232 patients met the inclusion criteria. Triple therapy was prescribed in 60.3% of patients, while 36.2% were prescribed quadruple therapy. Among the study population, 87.1% were on guideline-directed beta-blocker (BB), 48.3% on angiotensin-converting enzyme inhibitors (ACEI), or angiotensin receptor blockers (ARB), 31% on angiotensin receptor/neprilysin inhibitor (ARNI), 72.4% on a mineralocorticoid receptor antagonist (MRA), and 52.2% were on a sodium-glucose cotransporter 2 inhibitor (SGLT2i). Prescribing rates of target doses of ACEI/ARB, ARNI, BB, MRAs, and SGLT2i were 29.5%, 13.9%, 23.2%, 81.5%, and 90.1% respectively. GDMT titration was performed by pharmacists on 12.9% of patients. Conclusion Significant underutilization of GDMT and optimal dose titration remain within a large health system. Clinical pharmacists within our institution were intermittently involved in optimizing GDMT within the patient population. This study suggests there are opportunities for pharmacists to assist with GDMT optimization.

  PublisherDOI

• Comparing vape use and perceptions among pharmacy and non-pharmacy students from two universities in the US and UK

  PubMed · 2025-05-03

  articleOpen access

  Introduction: Little research exists regarding pharmacy student vaping habits or differences among students from different countries. Methods: A novel 19-item questionnaire was distributed in November 2023 to students at The University of Bath (United Kingdom) and The University of Texas at Austin (United States) to compare vape use and perceptions among pharmacy and non-pharmacy students from the two universities. All pharmacy students at both institutions were invited to complete the survey. A non-pharmacy student control group was identified through snowball sampling (i.e., the survey was distributed to a convenience sample of non-pharmacy students at each school, asking them to complete and distribute to peers). To incentivize participation, one respondent received a $100 reward. Data was analyzed using descriptive statistics. Chi-square and Wilcoxon Rank Sum tests were used to compare answers between pharmacy and non-pharmacy and UK and US participants. A p-value < 0.05 was deemed significant. Results: Overall, 372 students completed the survey (25% pharmacy student response rate). Vape use significantly differed between pharmacy and non-pharmacy students (p = 0.03). Among 212 pharmacy students, 49% reported vape ever-use versus 59% of the 158 non-pharmacy students. Significant differences were found in harm perceptions; more pharmacy students believed vapes are cancer-causing, affect the health of others nearby, should be banned in public, and are ineffective for quitting cigarettes. Few differences were observed between UK and US students. Conclusion: Pharmacy students were less likely to vape and exhibited heightened awareness of associated risks than non-pharmacy students. Few differences were observed between UK and US students surveyed.

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Recent grants

• NRSA Training Core (TL1)

  NIH · $1.8M · 2018–2023

Frequent coauthors

• Kelly R. Reveles

  The University of Texas at Austin

  302 shared

• Eric M. Mortensen

  University of Connecticut

  242 shared

• Jim M. Koeller

  Austin College

  232 shared

• Grace C. Lee

  South Texas Veterans Health Care System

  232 shared

• Chengwen Teng

  154 shared

• Xavier Jones

  137 shared

• Russell T. Attridge

  University of the Incarnate Word

  112 shared

• Obiageri O. Obodozie-Ofoegbu

  The University of Texas Health Science Center at San Antonio

  102 shared

Labs

• Frei LabPI

Education

• Masters of Science

  The University of Texas at Austin College of Pharmacy

  2003

• Doctor of Pharmacy

  The University of Texas at Austin Graduate School

  2001

Awards & honors

• Mentor of the Year by the Texas Society of Health System Pha…
• Young Investigator of the Year by the Society of Infectious…
• Distinguished Young Alumnus of the Year by the UT Austin Col…
• Fellow of the American College of Clinical Pharmacy
• Ambassador for the NIH Loan Repayment Program