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Browsing by Author "Cohen-Wolkowiez, Michael"
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Item Antibiotic Safety and Effectiveness in Premature Infants With Complicated Intraabdominal Infections(Wolters Kluwer, 2021) Smith, Michael J.; Boutzoukas, Angelique; Autmizguine, Julie; Hudak, Mark L.; Zinkhan, Erin; Bloom, Barry T.; Heresi, Gloria; Lavery, Adrian P.; Courtney, Sherry E.; Sokol, Gregory M.; Cotten, C. Michael; Bliss, Joseph M.; Mendley, Susan; Bendel, Catherine; Dammann, Christiane E. L.; Weitkamp, Jörn-Hendrik; Saxonhouse, Matthew A.; Mundakel, Gratias T.; Debski, Julie; Sharma, Gaurav; Erinjeri, Jinson; Gao, Jamie; Benjamin, Daniel K., Jr.; Hornik, Christoph P.; Smith, P. Brian; Cohen-Wolkowiez, Michael; Best Pharmaceuticals for Children Act—Pediatric Trials Network Steering Committee; Pediatrics, School of MedicineBackground: In premature infants, complicated intraabdominal infections (cIAIs) are a leading cause of morbidity and mortality. Although universally prescribed, the safety and effectiveness of commonly used antibiotic regimens have not been established in this population. Methods: Infants ≤33 weeks gestational age and <121 days postnatal age with cIAI were randomized to ≤10 days of ampicillin, gentamicin, and metronidazole (group 1); ampicillin, gentamicin, and clindamycin (group 2); or piperacillin-tazobactam and gentamicin (group 3) at doses stratified by postmenstrual age. Due to slow enrollment, a protocol amendment allowed eligible infants already receiving study regimens to enroll without randomization. The primary outcome was mortality within 30 days of study drug completion. Secondary outcomes included adverse events, outcomes of special interest, and therapeutic success (absence of death, negative cultures, and clinical cure score >4) 30 days after study drug completion. Results: One hundred eighty infants [128 randomized (R), 52 nonrandomized (NR)] were enrolled: 63 in group 1 (45 R, 18 NR), 47 in group 2 (41 R, 6 NR), and 70 in group 3 (42 R, 28 NR). Thirty-day mortality was 8%, 7%, and 9% in groups 1, 2, and 3, respectively. There were no differences in safety outcomes between antibiotic regimens. After adjusting for treatment group and gestational age, mortality rates through end of follow-up were 4.22 [95% confidence interval (CI): 1.39-12.13], 4.53 (95% CI: 1.21-15.50), and 4.07 (95% CI: 1.22-12.70) for groups 1, 2, and 3, respectively. Conclusions: Each of the antibiotic regimens are safe in premature infants with cIAI.Item Opportunistic dried blood spot sampling validates and optimizes a pediatric population pharmacokinetic model of metronidazole(American Society for Microbiology, 2024) Randell, Rachel L.; Balevic, Stephen J.; Greenberg, Rachel G.; Cohen-Wolkowiez, Michael; Thompson, Elizabeth J.; Venkatachalam, Saranya; Smith, Michael J.; Bendel, Catherine; Bliss, Joseph M.; Chaaban, Hala; Chhabra, Rakesh; Dammann, Christiane E. L.; Downey, L. Corbin; Hornik, Chi; Hussain, Naveed; Laughon, Matthew M.; Lavery, Adrian; Moya, Fernando; Saxonhouse, Matthew; Sokol, Gregory M.; Trembath, Andrea; Weitkamp, Joern-Hendrik; Hornik, Christoph P.; Best Pharmaceuticals for Children Act – Pediatric Trials Network Steering Committee; Pediatrics, School of MedicinePharmacokinetic models rarely undergo external validation in vulnerable populations such as critically ill infants, thereby limiting the accuracy, efficacy, and safety of model-informed dosing in real-world settings. Here, we describe an opportunistic approach using dried blood spots (DBS) to evaluate a population pharmacokinetic model of metronidazole in critically ill preterm infants of gestational age (GA) ≤31 weeks from the Metronidazole Pharmacokinetics in Premature Infants (PTN_METRO, NCT01222585) study. First, we used linear correlation to compare 42 paired DBS and plasma metronidazole concentrations from 21 preterm infants [mean (SD): post natal age 28.0 (21.7) days, GA 26.3 (2.4) weeks]. Using the resulting predictive equation, we estimated plasma metronidazole concentrations (ePlasma) from 399 DBS collected from 122 preterm and term infants [mean (SD): post natal age 16.7 (15.8) days, GA 31.4 (5.1) weeks] from the Antibiotic Safety in Infants with Complicated Intra-Abdominal Infections (SCAMP, NCT01994993) trial. When evaluating the PTN_METRO model using ePlasma from the SCAMP trial, we found that the model generally predicted ePlasma well in preterm infants with GA ≤31 weeks. When including ePlasma from term and preterm infants with GA >31 weeks, the model was optimized using a sigmoidal Emax maturation function of postmenstrual age on clearance and estimated the exponent of weight on volume of distribution. The optimized model supports existing dosing guidelines and adds new data to support a 6-hour dosing interval for infants with postmenstrual age >40 weeks. Using an opportunistic DBS to externally validate and optimize a metronidazole population pharmacokinetic model was feasible and useful in this vulnerable population.Item Safety of sildenafil in extremely premature infants: a phase I trial(Springer Nature, 2022-01) Jackson, Wesley; Gonzalez, Daniel; Smith, P. Brian; Ambalavanan, Namasivayam; Atz, Andrew M.; Sokol, Gregory M.; Hornik, Chi D.; Stewart, Dan; Mundakel, Gratias; Poindexter, Brenda B.; Ahlfeld, Shawn K.; Mills, Mary; Cohen-Wolkowiez, Michael; Martz, Karen; Hornik, Christoph P.; Laughon, Matthew M.; Pediatrics, School of MedicineObjective: To characterize the safety of sildenafil in premature infants. Study design: A phase I, open-label trial of sildenafil in premature infants receiving sildenafil per usual clinical care (cohort 1) or receiving a single IV dose of sildenafil (cohort 2). Safety was evaluated based on adverse events (AEs), transaminase levels, and mean arterial pressure monitoring. Results: Twenty-four infants in cohort 1 (n = 25) received enteral sildenafil. In cohort 2, infants received a single IV sildenafil dose of 0.25 mg/kg (n = 7) or 0.125 mg/kg (n = 2). In cohort 2, there was one serious AE related to study drug involving hypotension associated with a faster infusion rate than specified by the protocol. There were no AEs related to elevated transaminases. Conclusion: Sildenafil was well tolerated by the study population. Drug administration times and flush rates require careful attention to prevent infusion-related hypotension associated with faster infusions of IV sildenafil in premature infants.