Coplen Johnson

Dr. Coplen Johnson

orcid

Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Verified
Journal Article
Open access
PDF file
Alan David KayeAlan David Kaye
Alan David Kaye
SSShivam Shah
Shivam Shah
CJCoplen Johnson
Coplen Johnson
AWAdalyn S. De Witt
Adalyn S. De Witt
ATAustin Thomassen
Austin Thomassen
SSSahar Shekoohi
Sahar Shekoohi
Tacrolimus and mycophenolate are important immunosuppressive agents used to prevent organ rejection in post-transplant patients. While highly effective, their use is associated with significant toxicity, requiring careful management. Tacrolimus, a calcineurin inhibitor, is linked to nephrotoxicity, neurotoxicity, metabolic disturbances such as diabetes mellitus and dyslipidemia, and cardiovascular complications such as hypertension and arrhythmias. Mycophenolate, a reversible inhibitor of inosine monophosphate dehydrogenase, frequently causes gastrointestinal disturbances, including diarrhea and colitis, as well as hematologic side effects like anemia and leukopenia, which increase infection risk. Therapeutic drug monitoring (TDM) and pharmacogenomics have emerged as essential strategies for mitigating these toxicities. TDM ensures tacrolimus trough levels are maintained within a therapeutic range, minimizing the risks of nephrotoxicity and rejection. Pharmacogenomic insights, such as CYP3A5 polymorphisms, allow for personalized tacrolimus dosing based on individual metabolic profiles. For mycophenolate, monitoring inosine monophosphate dehydrogenase activity provides a pharmacodynamic approach to dose optimization, reducing gastrointestinal and hematologic toxicities. Emerging tools, including dried blood spot sampling and pharmacokinetic modeling, offer innovative methods to simplify monitoring and enhance precision in outpatient settings. Despite their utility, the toxicity profiles of these drugs, including those of early immunosuppressants such as cyclosporine and azathioprine, necessitate further consideration of alternative immunosuppressants like sirolimus, everolimus, and belatacept. Although promising, these newer agents require careful patient selection and further research. Future directions in immunosuppressive therapy include integrating individual pharmacogenetic data to refine dosing, minimize side effects, and improve long-term graft outcomes. This narrative review underscores the importance of personalized medicine and advanced monitoring in optimizing post-transplant care.

11 April 2025 in Medicine
Verified
Journal Article
Open access
CSChristopher Bs Stevens
Christopher Bs Stevens
DSDylan Bs Scott
Dylan Bs Scott
PRPrerana Ramesh
Prerana Ramesh
ARAmanda Bs Ragland
Amanda Bs Ragland
CJCoplen Johnson
Coplen Johnson
LALuis De Alba
Luis De Alba
Abdominal abscesses are commonly treated using percutaneous abscesses drainage (PAD). Despite PAD becoming commonplace in clinical practice, there are still unanswered questions and absent formal guidelines regarding its use. This narrative review discusses the evolution and different features of PAD, including the imaging modalities used in the process, catheter anatomy and sizes, placement techniques, the quantity of catheter side holes, and factors that determine the length of catheter stay and the usage of antibiotics for treating abdominal abscesses. Based on a retrospective review of the existing literature, this work is presented with an intent of identifying the most efficient design aspects and indications to optimize clinical success when performing PAD. This manuscript shows that there are still many unanswered questions and room for improvement regarding percutaneous drainage of abscesses.

23 November 2024 in Nutrients
Verified
Journal Article
Open access
PDF file
CJCoplen Johnson
Coplen Johnson
CSChristopher Stevens
Christopher Stevens
MBMatthew R. Bennett
Matthew R. Bennett
ALAdam Benjamin Litch
Adam Benjamin Litch
EREugenie M. Rodrigue
Eugenie M. Rodrigue
MAMassoud Allahyari
Massoud Allahyari
Hepatic encephalopathy (HE) is a neuropsychiatric condition frequently associated with cirrhosis and portosystemic shunting (PSS). It imposes a significant clinical and economic burden, with increasing attention toward identifying modifiable factors that could improve outcomes. Emerging evidence suggests that vitamin D deficiency (VDD), prevalent in patients with cirrhosis, may contribute to the development and severity of HE. This review explores the association between VDD and HE by analyzing the underlying pathophysiology, including oxidative stress, ammonia accumulation, and impaired hepatic function. Additionally, we summarize recent studies highlighting the correlation between low serum 25-hydroxy vitamin D (25-OHD) levels and worsening grades of HE. Despite strong observational data, interventional studies on vitamin D (VD) supplementation for HE remains limited. Current evidence suggests that VD’s antioxidant properties may alleviate oxidative stress in HE, with potential benefits in mitigating disease severity. Future research should focus on longitudinal studies and randomized controlled trials to evaluate the clinical impact of VD supplementation on HE outcomes and explore VD’s role in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) procedures. Understanding the therapeutic potential of VD could lead to improved management strategies for HE and cirrhotic patients at large.

14 January 2025 in Current Pain and Headache Reports
Verified
Journal Article
Closed access
PDF file
Alan David KayeAlan David Kaye
Alan David Kaye
BTBrynne E. Tynes
Brynne E. Tynes
CJCoplen Johnson
Coplen Johnson
BSBryan C. Strong
Bryan C. Strong
BABrennan M. Abbott
Brennan M. Abbott
SSSahar Shekoohi
Sahar Shekoohi

24 April 2025 in Current Pain and Headache Reports
Verified
Journal Article
Closed access
PDF file
Alan David KayeAlan David Kaye
Alan David Kaye
ANAngela Nguyen
Angela Nguyen
ATAustin Thomassen
Austin Thomassen
APAllison M. Picou
Allison M. Picou
NTNicholas L. Thomas
Nicholas L. Thomas
SSSahar Shekoohi
Sahar Shekoohi

2 January 2025 in Current Pain and Headache Reports
Verified
Journal Article
Closed access
PDF file
Alan David KayeAlan David Kaye
Alan David Kaye
JAJoseph R. Archer
Joseph R. Archer
SSShivam Shah
Shivam Shah
CJCoplen Johnson
Coplen Johnson
LHLexa R. Herron
Lexa R. Herron
ACAzem A. Chami
Azem A. Chami