Kari A. Mergenhagen
United States Department of Veterans Affairs
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Featured researches published by Kari A. Mergenhagen.
Clinical Therapeutics | 2016
Jennifer L. Schroeck; James Ford; Erin L. Conway; Kari Kurtzhalts; Megan E. Gee; Krista A. Vollmer; Kari A. Mergenhagen
PURPOSE Insomnia is problematic for older adults. After behavioral modifications fail to show adequate response, pharmacologic options are used. The pharmacokinetics of agents used to treat insomnia may be altered. This review focuses on the safety and efficacy of medications used to treat insomnia. METHODS A literature search of Medline, PubMed, and Embase was conducted (January 1966-June 2016). It included systematic reviews, randomized controlled trials, observational studies, and case series that had an emphasis on insomnia in an older population. Search terms included medications approved by the US Food and Drug Administration for insomnia: benzodiazepines (triazolam, estazolam, temazepam, flurazepam, and quazepam), nonbenzodiazepine receptor agonists (non-BzRAs; zaleplon, zolpidem, and eszopiclone), suvorexant, ramelteon, doxepin and trazodone. Off-label drugs such as other antidepressants, antihistamines, antipsychotics, gabapentin, pramipexole, tiagabine, valerian, and melatonin were also included. FINDINGS Cognitive behavioral therapy and sleep hygiene are considered initial therapy for insomnia. Benzodiazepines are discouraged in the geriatric population, especially for long-term use. Although non-BzRAs have improved safety profiles compared with benzodiazepines, their side effects include dementia, serious injury, and fractures, which should limit their use. Ramelteon has a minimal adverse effect profile and is effective for sleep-onset latency and increased total sleep time, making it a valuable first-line option. Although the data on suvorexant are limited, this drug improves sleep maintenance and has mild adverse effects, including somnolence; residual daytime sedation has been reported, however. Sedating low-dose antidepressants should only be used for insomnia when the patient has comorbid depression. Antipsychotic agents, pramipexole, and tiagabine have all been used for insomnia, but none has been extensively studied in an older population, and all have considerable adverse effects. Gabapentin may be useful in patients with restless leg syndrome or chronic neuropathic pain and insomnia. Diphenhydramine should be avoided in the elderly. Valerian and melatonin are unregulated products that have a small impact on sleep latency and can produce residual sedation. IMPLICATIONS An ideal treatment for insomnia should help to improve sleep latency and sleep duration with limited awakenings and be without significant adverse effects such as daytime somnolence or decreased alertness. Cognitive behavioral therapy should always be first line treatment. Clinical inertia regarding previous prominent use of benzodiazepines and non-BzRAs will be a significant challenge for patients accustomed to their issuance. The future direction of insomnia treatment should have an emphasis on nonpharmacologic interventions, treating comorbid conditions, and focusing therapy on using benzodiazepines and non-BzRAs as last resorts.
Clinical Therapeutics | 2015
Christine A. Ruh; Ganapathi Parameswaran; Amy L. Wojciechowski; Kari A. Mergenhagen
PURPOSE The use of outpatient parenteral antibiotic therapy (OPAT) programs has become more frequent because of benefits in costs with equivalent clinical outcomes compared with inpatient care. The purpose of this study was to evaluate the outcomes of our program. A modified pharmacoeconomic analysis was performed to compare costs of our program with hospital or rehabilitation facility care. METHODS This was a retrospective chart review of 96 courses of OPAT between April 1, 2011, and July 31, 2013. Clinical failures were defined as readmission or death due to worsening infection or readmission secondary to adverse drug event (ADE) to antibiotic therapy. This does not include those patients readmitted for reasons not associated with OPAT therapy, including comorbidities or elective procedures. Baseline characteristics and program-specific data were analyzed. Statistically significant variables were built into a multivariate logistic regression model to determine predictors of failure. A pharmacoeconomic analysis was performed with the use of billing records. FINDINGS Of the total episodes evaluated, 17 (17.71%) clinically failed therapy, and 79 (82.29%) were considered a success. In the multivariate analysis, number of laboratory draws (P = 0.02) and occurrence of drug reaction were significant in the final model, P = 0.02 and P = 0.001, respectively. The presence an adverse drug reaction increases the odds of failure (OR = 10.10; 95% CI, 2.69-44.90). Compared with inpatient or rehabilitation care, the cost savings was
Case Reports | 2017
Kari Kurtzhalts; Kari A. Mergenhagen; Akshay Manohar; Charles S. Berenson
6,932,552.03 or
Infectious diseases | 2017
Iffat Shafiq; Zackery P. Bulman; Sarah L. Spitznogle; Justin E. Osorio; Irene S. Reilly; Alan J. Lesse; Ganapathi Parameswaran; Kari A. Mergenhagen; Brian T. Tsuji
2,649,870.68, respectively. IMPLICATIONS In our study, patients tolerated OPAT well, with a low number of failures due to ADE. The clinical outcomes and cost savings of our program indicate that OPAT can be a viable alternative to long-term inpatient antimicrobial therapy.
Anaerobe | 2014
Amy L. Wojciechowski; Ganapathi Parameswaran; Arun Mattappallil; Kari A. Mergenhagen
New antibiotic options are needed for the treatment of multidrug-resistant (MDR) Pseudomonas infections. We present a case of a man aged 64 years with a bladder fistula due to radiation, ultimately causing osteomyelitis of the pubic symphysis. Repeated antibiotic courses, without correcting the fistula, resulted in infection with MDR Pseudomonas aeruginosa. He was successfully treated for his osteomyelitis through cystectomy, aggressive debridement and a prolonged course of antimicrobials directed at the MDR Pseudomonas isolate.
Case Reports | 2016
Caroline R Brotzki; Kari A. Mergenhagen; Zackery P. Bulman; Brian T. Tsuji; Charles S. Berenson
Abstract There is an urgent need to optimize therapeutic options in patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia who have failed conventional therapy. Two clinical isolates were obtained from a 68-year-old male with persistent MRSA bacteremia before and after the development of daptomycin nonsusceptibility. The pharmacodynamic activity of monotherapies and combinations of ceftaroline, daptomycin, cefoxitin, nafcillin and vancomycin were evaluated in time-kill experiments versus 108 CFU/mL of the pre- and post-daptomycin nonsusceptible MRSA isolates. Cefoxitin, nafcillin and vancomycin alone or in combination with ceftaroline failed to generate prolonged bactericidal activity against the post-daptomycin nonsusceptible isolate whereas a ceftaroline–daptomycin combination resulted in 6, 24 and 48 h log10(CFU/mL) reductions of 3.90, 4.40 and 6.32. Population analysis profiles revealed a daptomycin heteroresistant subpopulation of the pre-daptomycin nonsusceptible MRSA isolate that expanded by >10,000× on daptomycin agar containing 2–16 mg/L in the post-daptomycin nonsusceptible isolate. Daptomycin and ceftaroline combinations may be promising against persistent MRSA bacteremia.
Antimicrobial Agents and Chemotherapy | 2015
Jennifer L. Schroeck; Christine A. Ruh; John A. Sellick; Michael C. Ott; Arun Mattappallil; Kari A. Mergenhagen
The impact of corticosteroid use on the incidence of Clostridium difficile-associated diarrhea (CDAD) was examined retrospectively in 532 patients receiving antibiotic treatment for respiratory infections. As determined by logistic regression, corticosteroids were associated with a decreased incidence of CDAD (Odds Ratio 0.12, 95% Confidence Interval 0.006-0.95).
/data/revues/07356757/unassign/S0735675718303280/ | 2018
Brittany Cieri; Erin L. Conway; John A. Sellick; Kari A. Mergenhagen
Infective endocarditis caused by Proteus mirabilis is a rare and poorly reported disease, with no well-defined effective antibiotic regimen. Here, we present a case of P. mirabilis aortic valve endocarditis. We reviewed prior cases and treatment regimens, and devised effective treatment, which was guided by in vitro sensitivity and synergy testing on the pathogen. Our patient survived without complications or the need for a surgical intervention.
Open Forum Infectious Diseases | 2017
Saloni Patel; Michael C. Ott; Kari A. Mergenhagen
We thank [Sanchez et al.][1] ([1][2]) for their comments on our paper ([2][3]) and apologize for the confusion as to the definitions used in that study. The time frame of the retrospective chart review was 2009 to 2011. We chose to assess appropriateness of antibiotics based on criteria available at
Open Forum Infectious Diseases | 2016
Zackery P. Bulman; Kari A. Mergenhagen; Alan J. Lesse; Ganapathi Parameswaran; Brian T. Tsuji