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Clinical Journal of the American... Jul 2019Antimicrobial pharmacology and its effect on prescribing is quite complex. Selecting an antibiotic that will optimally treat an infection while minimizing adverse... (Review)
Review
Antimicrobial pharmacology and its effect on prescribing is quite complex. Selecting an antibiotic that will optimally treat an infection while minimizing adverse effects and the development of resistance is only the first step, as one must also consider the patient's individual pharmacokinetic alterations and the pharmacodynamic properties of the drug when prescribing it as well. Patients with CKD may have alterations in their protein binding, volumes of distribution, kidney clearance, and nonrenal clearance that necessitates antibiotic dose adjustments to prevent the development of toxicity. Knowledge of a drug's pharmacodynamics, defined as the relationship between drug exposure and antibacterial efficacy, provides some guidance regarding the optimal way to make dose adjustments. Different pharmacodynamic goals, such as maximizing the time that free (unbound) drug concentrations spend above the minimum inhibitory concentration (MIC) for time dependent drugs (, -lactams) or maximizing the free peak-to-MIC ratio for concentration-dependent antibiotics (, aminoglycosides), require different adjustment strategies; for instance, decreasing the dose while maintaining normal dosing frequency or giving normal (or even larger) doses less frequently, respectively. Patients receiving hemodialysis have other important prescribing considerations as well. The nephrologist or patient may prefer to receive antibiotics that can be administered intravenously toward the end of a dialysis session. Additionally, newer dialysis technologies and filters can increase drug removal more than originally reported. This review will discuss the place in therapy, mechanism of action, pharmacokinetic, pharmacodynamic, and other pharmacologic considerations encountered when prescribing commonly used antibiotics in patients with chronic kidney disease or ESKD.
Topics: Aminoglycosides; Anti-Bacterial Agents; Fluoroquinolones; Humans; Lipopeptides; Methicillin-Resistant Staphylococcus aureus; Renal Insufficiency, Chronic; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 30862698
DOI: 10.2215/CJN.08140718 -
International Journal of Environmental... Feb 2022(1) Background: pneumonia (PCP) has a substantial impact on the morbidity and mortality of patients, especially those with autoimmune disorders, thus requiring optimal... (Review)
Review
(1) Background: pneumonia (PCP) has a substantial impact on the morbidity and mortality of patients, especially those with autoimmune disorders, thus requiring optimal dosing strategies of Trimethoprim-Sulfamethoxazole (TMP-SMX). Therefore, to ensure the safety of TMP-SMX, there is a high demand to review current evidence in PCP patients with a focus on dose optimization strategies; (2) Methods: Various databases were searched from January 2000 to December 2021 for articles in English, focusing on the dose optimization of TMP-SMX. The data were collected in a specific form with predefined inclusion and exclusion criteria. The quality of each article was evaluated using a Newcastle-Ottawa Scale (NOS) for retrospective studies, Joanna Briggs Institute (JBI) critical checklist for case reports, and Cochrane bias tool for randomized clinical trials (RCTs); (3) Results: Thirteen studies met the inclusion criteria for final analysis. Of the 13 selected studies, nine were retrospective cohort studies, two case reports, and two randomized controlled trials (RCT). Most of the studies compared the high-dose with low-dose TMP-SMX therapy for PCP. We have found that a low dose of TMP-SMX provides satisfactory outcomes while reducing the mortality rate and PCP-associated adverse events. This strategy reduces the economic burden of illness and enhances patients' compliance to daily regimen plan; (4) Conclusions: The large-scale RCTs and cohort studies are required to improve dosing strategies to prevent initial occurrence of PCP or to prevent recurrence of PCP in immune compromised patients.
Topics: Cohort Studies; Humans; Pneumonia, Pneumocystis; Retrospective Studies; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 35270525
DOI: 10.3390/ijerph19052833 -
JAMA Jul 2021Determination of optimal treatment durations for common infectious diseases is an important strategy to preserve antibiotic effectiveness. (Comparative Study)
Comparative Study Randomized Controlled Trial
IMPORTANCE
Determination of optimal treatment durations for common infectious diseases is an important strategy to preserve antibiotic effectiveness.
OBJECTIVE
To determine whether 7 days of treatment is noninferior to 14 days when using ciprofloxacin or trimethoprim/sulfamethoxazole to treat urinary tract infection (UTI) in afebrile men.
DESIGN, SETTING, AND PARTICIPANTS
Randomized, double-blind, placebo-controlled noninferiority trial of afebrile men with presumed symptomatic UTI treated with ciprofloxacin or trimethoprim/sulfamethoxazole at 2 US Veterans Affairs medical centers (enrollment, April 2014 through December 2019; final follow-up, January 28, 2020). Of 1058 eligible men, 272 were randomized.
INTERVENTIONS
Participants continued the antibiotic prescribed by their treating clinician for 7 days of treatment and were randomized to receive continued antibiotic therapy (n = 136) or placebo (n = 136) for days 8 to 14 of treatment.
MAIN OUTCOMES AND MEASURES
The prespecified primary outcome was resolution of UTI symptoms by 14 days after completion of active antibiotic treatment. A noninferiority margin of 10% was selected. The as-treated population (participants who took ≥26 of 28 doses and missed no more than 2 consecutive doses) was used for the primary analysis, and a secondary analysis included all patients as randomized, regardless of treatment adherence. Secondary outcomes included recurrence of UTI symptoms and/or adverse events within 28 days of stopping study medication.
RESULTS
Among 272 patients (median [interquartile range] age, 69 [62-73] years) who were randomized, 100% completed the trial and 254 (93.4%) were included in the primary as-treated analysis. Symptom resolution occurred in 122/131 (93.1%) participants in the 7-day group vs 111/123 (90.2%) in the 14-day group (difference, 2.9% [1-sided 97.5% CI, -5.2% to ∞]), meeting the noninferiority criterion. In the secondary as-randomized analysis, symptom resolution occurred in 125/136 (91.9%) participants in the 7-day group vs 123/136 (90.4%) in the 14-day group (difference, 1.5% [1-sided 97.5% CI, -5.8% to ∞]) Recurrence of UTI symptoms occurred in 13/131 (9.9%) participants in the 7-day group vs 15/123 (12.9%) in the 14-day group (difference, -3.0% [95% CI, -10.8% to 6.2%]; P = .70). Adverse events occurred in 28/136 (20.6%) participants in the 7-day group vs 33/136 (24.3%) in the 14-day group.
CONCLUSIONS AND RELEVANCE
Among afebrile men with suspected UTI, treatment with ciprofloxacin or trimethoprim/sulfamethoxazole for 7 days was noninferior to 14 days of treatment with regard to resolution of UTI symptoms by 14 days after antibiotic therapy. The findings support the use of a 7-day course of ciprofloxacin or trimethoprim/sulfamethoxazole as an alternative to a 14-day course for treatment of afebrile men with UTI.
TRIAL REGISTRATION
ClinicalTrials.gov identifier: NCT01994538.
Topics: Aged; Anti-Bacterial Agents; Ciprofloxacin; Double-Blind Method; Drug Administration Schedule; Duration of Therapy; Humans; Male; Middle Aged; Trimethoprim, Sulfamethoxazole Drug Combination; Urinary Tract Infections; Urine
PubMed: 34313686
DOI: 10.1001/jama.2021.9899 -
Science Translational Medicine Dec 2021Although systemic antibiotics are critical in controlling infections and reducing morbidity and mortality, overuse of antibiotics is presumed to contribute to negative... (Randomized Controlled Trial)
Randomized Controlled Trial
Although systemic antibiotics are critical in controlling infections and reducing morbidity and mortality, overuse of antibiotics is presumed to contribute to negative repercussions such as selection of antimicrobial-resistant organisms and collateral damage to commensal microbes. In a prospective, randomized study of four clinically relevant antibiotic regimens [doxycycline (20 mg or 100 mg), cephalexin, or trimethoprim/sulfamethoxazole], we investigated microbial alterations on skin after administration of systemic antibiotics to healthy human volunteers. Samples from different skin and oral sites, as well as stool, were collected before, during, and up to 1 year after antibiotic use, and shotgun metagenomic sequencing was performed. Taxonomic analysis showed that subjects receiving doxycycline 100 mg and trimethoprim/sulfamethoxazole (TMP/SMX) exhibited greater changes to their skin microbial communities, as compared to those receiving other regimens or untreated controls. Oral and stool microbiota also demonstrated fluctuations after antibiotics. Bacterial culturing in combination with whole-genome sequencing revealed specific emergence, expansion, and persistence of antibiotic-resistant staphylococci harboring or and or genes in all subjects who received doxycycline 100 mg or TMP/SMX, respectively. Last, analysis of metagenomic data revealed an increase of genes involved in gene mobilization, indicating stress responses of microbes to antibiotics. Collectively, these findings demonstrate direct, long-lasting effects of antibiotics on skin microbial communities, highlighting the skin microbiome as a site for the development and persistence of antibiotic resistance and the risks of overprescribing.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Humans; Microbiota; Prospective Studies; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 34936382
DOI: 10.1126/scitranslmed.abd8077 -
Annals of the Rheumatic Diseases May 2023Severe infections contribute to morbidity and mortality in antineutrophil cytoplasm antibody-associated vasculitis (AAV). This study aimed to identify risk factors...
OBJECTIVES
Severe infections contribute to morbidity and mortality in antineutrophil cytoplasm antibody-associated vasculitis (AAV). This study aimed to identify risk factors associated with severe infections in participants of the Rituximab versus Cyclophosphamide for ANCA-Associated Vasculitis (RAVE) trial.
METHODS
Data on 197 patients recruited into the RAVE trial were analysed. Participants received either rituximab (RTX) or cyclophosphamide (CYC), followed by azathioprine (AZA). Clinical and laboratory data of patients with and without severe infections (≥grade 3, according to the Common Terminology Criteria for Adverse Events version 3.0) were compared. Risk factors for severe infections were investigated using Cox-regression models.
RESULTS
Eighteen of 22 (82%) severe infections occurred within 6 months after trial entry, most commonly respiratory tract infections (15/22, 68%). At baseline, lower absolute numbers of CD19+ cells were observed in patients with severe infections either receiving RTX or CYC/AZA at baseline, while CD5+B and CD3+T cells did not differ between groups. In Cox-regression analysis, higher baseline serum immunoglobulin M levels were associated with the risk of severe infections, whereby a higher baseline total CD19+B cell number and prophylaxis against with trimethoprim-sulfamethoxazole (TMP/SMX) with decreased risk of severe infections. Use of TMP/SMX was associated with lower risk of severe infections in both groups, receiving either RTX or CYC/AZA.
CONCLUSIONS
The use of low-dose TMP/SMX is associated with reduced risk of severe infections in patients with AAV treated with either RTX or CYC/AZA. Reduced B cell subpopulations at start of treatment might be a useful correlate of reduced immunocompetence.
Topics: Humans; Rituximab; Trimethoprim, Sulfamethoxazole Drug Combination; Antibodies, Monoclonal, Murine-Derived; Remission Induction; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Cyclophosphamide; Azathioprine; Risk Factors; Treatment Outcome
PubMed: 36702528
DOI: 10.1136/ard-2022-223401 -
Minerva Medica Aug 2021The antimicrobial trimethoprim is structurally related to potassium-sparing diuretics and may consequently lead to derangements in electrolyte and acid-base balance....
INTRODUCTION
The antimicrobial trimethoprim is structurally related to potassium-sparing diuretics and may consequently lead to derangements in electrolyte and acid-base balance. Since no report so far analyzed the literature documenting individual cases with electrolyte and acid-base derangements induced by trimethoprim, a systematic review was carried out.
EVIDENCE ACQUISITION
We retained 53 reports documenting 68 cases (42 males and 26 females 23 to 96 years of age) of electrolyte or acid-base derangements occurring on trimethoprim for about 5 days.
EVIDENCE SYNTHESIS
One hundred five electrolyte imbalances were detected in the 68 patients: hyperkalemia (>5.0 mmol/L) in 62 (91%), hyponatremia (<135 mmol/L) in 29 (43%) and metabolic acidosis (pH<7.38 and bicarbonate <19 mmol/L) in 14 (21%) cases. Following possible predisposing factors for electrolyte and acid-base abnormalities were found in 54 (79%) patients: high-dose trimethoprim, comedication with drugs that have been associated with electrolyte and acid-base derangements, preexisting kidney disease, age ≥80 years and diabetes mellitus.
CONCLUSIONS
High-dose trimethoprim, comedicated with drugs that have been associated with electrolyte and acid-base derangements, poor kidney function, age ≥80 years and diabetes mellitus predispose to trimethoprim-associated electrolyte and acid-base abnormalities. Clinicians must recognize patients at risk, possibly avoid drug combinations that may worsen the problem and monitor the laboratory values.
Topics: Acidosis; Adult; Aged; Aged, 80 and over; Anti-Infective Agents, Urinary; Bicarbonates; Diabetes Complications; Female; Humans; Hyperkalemia; Hyponatremia; Kidney Diseases; Male; Middle Aged; Trimethoprim; Young Adult
PubMed: 32697061
DOI: 10.23736/S0026-4806.20.06660-4 -
Health Technology Assessment... May 2022Daily, low-dose antibiotic prophylaxis is the current standard care for women with recurrent urinary tract infection. Emerging antimicrobial resistance is a global... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Daily, low-dose antibiotic prophylaxis is the current standard care for women with recurrent urinary tract infection. Emerging antimicrobial resistance is a global health concern, prompting research interest in non-antibiotic agents such as methenamine hippurate, but comparative data on their efficacy and safety are lacking.
OBJECTIVE
To assess the clinical effectiveness and cost-effectiveness of methenamine hippurate (Hiprex; Mylan NV, Canonsburg, PA, USA) compared with current standard care (antibiotic prophylaxis) for recurrent urinary tract infection prevention in adult women.
DESIGN
Multicentre, pragmatic, open-label, randomised, non-inferiority trial of 12 months' treatment with the allocated intervention, including an early, embedded qualitative study and a 6-month post-treatment observation phase. The predefined non-inferiority margin was one urinary tract infection per person-year.
SETTING
Eight UK NHS secondary care sites.
PARTICIPANTS
A total of 240 adult women with recurrent urinary tract infection requiring preventative treatment participated in the trial.
INTERVENTIONS
A central randomisation system allocated participants 1 : 1 to the experimental (methenamine hippurate: 1 g twice daily) or control (once-daily low-dose antibiotics: 50/100 mg of nitrofurantoin, 100 mg of trimethoprim or 250 mg of cefalexin) arm. Crossover between treatment arms was permitted.
MAIN OUTCOME MEASURES
The primary clinical outcome was incidence of symptomatic antibiotic-treated urinary tract infection during the 12-month treatment period. Cost-effectiveness was assessed by incremental cost per quality-adjusted life-year gained, extrapolated over the patient's expected lifetime using a Markov cohort model. Secondary outcomes included post-treatment urinary tract infections, total antibiotic use, microbiologically proven urinary tract infections, antimicrobial resistance, bacteriuria, hospitalisations and treatment satisfaction.
RESULTS
Primary modified intention-to-treat analysis comprised 205 (85%) randomised participants [102/120 (85%) participants in the antibiotics arm and 103/120 (86%) participants in the methenamine hippurate arm] with at least 6 months' data available. During treatment, the incidence rate of symptomatic, antibiotic-treated urinary tract infections decreased substantially in both arms to 1.38 episodes per person-year (95% confidence interval 1.05 to 1.72 episodes per person-year) for methenamine hippurate and 0.89 episodes per person year (95% confidence interval 0.65 to 1.12 episodes per person-year) for antibiotics (absolute difference 0.49; 90% confidence interval 0.15 to 0.84). This absolute difference did not exceed the predefined, strict, non-inferiority limit of one urinary tract infection per person-year. On average, methenamine hippurate was less costly and more effective than antibiotics in terms of quality-adjusted life-years gained; however, this finding was not consistent over the longer term. The urinary tract infection incidence rate 6 months after treatment completion was 1.72 episodes per year in the methenamine hippurate arm and 1.19 in the antibiotics arm. During treatment, 52% of urine samples taken during symptomatic urinary tract infections were microbiologically confirmed and higher proportions of participants taking daily antibiotics (46/64; 72%) demonstrated antibiotic resistance in cultured from perineal swabs than participants in the methenamine hippurate arm (39/70; 56%) (-value = 0.05). Urine cultures revealed that during treatment higher proportions of participants and samples from the antibiotic arm grew resistant to trimethoprim/co-trimoxazole and cephalosporins, respectively. Conversely, post treatment, higher proportions of participants in the methenamine hippurate arm (9/45; 20%) demonstrated multidrug resistance in isolated from perineal swabs than participants in the antibiotic arm (2/39; 5%) ( = 0.06). All other secondary outcomes and adverse events were similar in both arms.
LIMITATIONS
This trial could not define whether or not one particular antibiotic was more beneficial, and progressive data loss hampered economic evaluation.
CONCLUSIONS
This large, randomised, pragmatic trial in a routine NHS setting has clearly shown that methenamine hippurate is not inferior to current standard care (daily low-dose antibiotics) in preventing recurrent urinary tract infections in women. The results suggest that antimicrobial resistance is proportionally higher in women taking prophylactic antibiotics.
RECOMMENDATIONS FOR RESEARCH
Future research should include evaluation of other non-antibiotic preventative treatments in well-defined homogeneous patient groups, preferably with the comparator of daily antibiotics.
TRIAL REGISTRATION
This trial is registered as ISRCTN70219762 and EudraCT 2015-003487-36.
FUNDING
This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in ; Vol. 26, No. 23. See the NIHR Journals Library website for further project information.
Topics: Adult; Anti-Bacterial Agents; Antibiotic Prophylaxis; Cost-Benefit Analysis; Escherichia coli; Female; Hippurates; Humans; Male; Methenamine; Trimethoprim; Urinary Tract Infections
PubMed: 35535708
DOI: 10.3310/QOIZ6538 -
JAMA Network Open Oct 2020Oral β-lactam antibiotics are traditionally not recommended to treat Enterobacterales bacteremia because of concerns over subtherapeutic serum concentrations, but there...
IMPORTANCE
Oral β-lactam antibiotics are traditionally not recommended to treat Enterobacterales bacteremia because of concerns over subtherapeutic serum concentrations, but there is a lack of outcomes data, specifically after initial treatment with parenteral antibiotics. Given the limited data and increasing limitations of fluoroquinolones or trimethoprim-sulfamethoxazole (TMP-SMX), oral β-lactam antibiotics may be a valuable additional treatment option.
OBJECTIVE
To compare definitive therapy with oral β-lactam antibiotics vs fluoroquinolones or TMP-SMX for Enterobacterales bacteremia from a suspected urine source.
DESIGN, SETTING, AND PARTICIPANTS
A retrospective cohort study was conducted from January 1, 2007, to September 30, 2015, at 114 Veterans Affairs hospitals among 4089 adults with Escherichia coli, Klebsiella spp, or Proteus spp bacteremia and matching urine culture results. Additional inclusion criteria were receipt of active parenteral antibiotic(s) followed by conversion to an oral antibiotic. Exclusion criteria were previous Enterobacterales bacteremia, urologic abscess, or chronic prostatitis. Data were analyzed from April 15, 2019, to July 26, 2020.
EXPOSURES
Conversion of therapy to an oral β-lactam antibiotic vs fluoroquinolones or TMP-SMX after 1 to 5 days of parenteral antibiotics.
MAIN OUTCOMES AND MEASURES
The main outcome was a composite of either 30-day all-cause mortality or 30-day recurrent bacteremia. Propensity-based overlap weights were used to adjust for differences between groups. Log binomial regression models were used to estimate adjusted relative risks (aRRs) and adjusted risk differences (aRDs).
RESULTS
Of the 4089 eligible patients (3731 men [91.2%]; median age, 71 years [interquartile range, 63-81 years]), 955 received an oral β-lactam antibiotic, and 3134 received fluoroquinolones or TMP-SMX. The primary outcome occurred for 42 patients (4.4%) who received β-lactam antibiotics and 94 patients (3.0%) who received fluoroquinolones or TMP-SMX (aRD, 0.99% [95% CI, -0.42% to 2.40%]; aRR, 1.31 [95% CI, 0.87-1.95]). Mortality rates were 3.0% (n = 29) for patients receiving β-lactam antibiotics vs 2.6% (n = 82) for those receiving fluoroquinolones or TMP-SMX (aRD, 0.06% [95% CI, -1.13% to 1.26%]; aRR, 1.02 [95% CI, 0.67-1.56]). Recurrent bacteremia rates were 1.5% (n = 14) among those receiving β-lactam antibiotics vs 0.4% (n = 12) among those receiving fluoroquinolones or TMP-SMX (aRD, 1.03% [95% CI, 0.24%-1.82%]; aRR, 3.43 [95% CI, 0.42-27.90]).
CONCLUSIONS AND RELEVANCE
In this cohort study of adults with E coli, Klebsiella spp, or Proteus spp bacteremia from a suspected urine source, the relative risk of recurrent bacteremia was not significantly higher with β-lactam antibiotics compared with fluoroquinolones or TMP-SMX, and the absolute risk and risk difference were small (ie, <3%). No significant difference in mortality was observed. Oral β-lactam antibiotics may be a reasonable step-down treatment option, primarily when alternative options are limited by resistance or adverse effects. Further study is needed because statistical power was limited owing to a low number of recurrent bacteremia events.
Topics: Aged; Aged, 80 and over; Anti-Bacterial Agents; Anti-Infective Agents, Urinary; Cohort Studies; Drug Resistance, Multiple, Bacterial; Enterobacteriaceae Infections; Female; Humans; Male; Middle Aged; Retrospective Studies; Trimethoprim, Sulfamethoxazole Drug Combination; Urinary Tract Infections; beta-Lactams
PubMed: 33030555
DOI: 10.1001/jamanetworkopen.2020.20166 -
Annals of Family Medicine Apr 2022Context: Rising antibiotic resistance has transcended hospital boundaries and impacted individuals with community acquired urinary tract infections (UTI). Scant data on...
Context: Rising antibiotic resistance has transcended hospital boundaries and impacted individuals with community acquired urinary tract infections (UTI). Scant data on antibiotic resistance in outpatient settings exists and most studies in the United States (U.S.) have identified predictors of resistance in acute-care settings. Objective: Determine the antibiogram among Escherichia coli isolates and factors associated with ciprofloxacin and trimethoprim-sulfamethoxazole (TMP-SMX) resistant gram-negative urinary isolates. Study Design: Retrospective cohort study. Setting: Two primary care, safety-net clinics in Houston, TX between 11/2018 and 3/2020. Population studied: Patients aged 18 and older presenting with provider suspected uncomplicated or complicated UTI. Outcome measures: Resistance and predictors of resistance to UTI-relevant antibiotics. Results: Among 1265 cultures collected, 372 (28.4%) were positive. We detected E. coli (50.3%) and Group B Streptococcus (18.6%) most frequently. Our patient population consisted mostly of Hispanic (75.7%) females (92.5%) born outside the U.S. (67.3%) with a mean age of 47. Among patients with E. coli isolated (n=189), antibiotic resistance was highest to ampicillin (63%), TMP-SMX (44%), ciprofloxacin (31%), and cefazolin (30%); no or low resistance against amikacin (0%), fosfomycin (0%), and nitrofurantoin (2.7%) was detected. Approximately 12% of E. coli isolates were extended-spectrum beta-lactamase positive. Having a prior UTI caused by a TMP-SMX resistant gram-negative organism and being born outside the U.S increased the odds of TMP-SMX resistance by 3.71 (95% confidence interval: 1.6-9.2) and 3.08 (95% CI: 1.6-6.3), respectively. Having a complicated UTI (odds ratio (OR): 3.58; 95% CI: 1.1-12.1), prior fluoroquinolone use (OR: 6.81; 95% CI: 1.7-34.1) and a prior UTI with ciprofloxacin resistance (OR: 7.84; 95% CI: 3.2-20.7) increased the odds of having a ciprofloxacin resistance. Conclusion: The Infectious Disease Society of America cautions against prescribing an antibiotic if regional resistance exceeds 20%. We constructed an antibiogram and found resistance surpassed this threshold for TMP-SMX and ciprofloxacin and identified factors associated with resistance to these agents. Assessing these characteristics during clinical decision making may improve antibiotic-organism susceptibility concordance in primary care.
Topics: Female; Humans; United States; Middle Aged; Male; Ciprofloxacin; Trimethoprim, Sulfamethoxazole Drug Combination; Escherichia coli; Retrospective Studies; Outpatients; Escherichia coli Infections; Drug Resistance, Bacterial; Urinary Tract Infections; Anti-Bacterial Agents; Microbial Sensitivity Tests
PubMed: 36944052
DOI: 10.1370/afm.20.s1.3177 -
The disposition of trimethoprim and sulfadiazine in neonatal foals after intravenous administration.Veterinary Medicine and Science May 2022Septicaemia in the neonatal foal is caused by both Gram positive and Gram negative bacteria. The life-threatening nature of this condition requires treatment to be...
BACKGROUND
Septicaemia in the neonatal foal is caused by both Gram positive and Gram negative bacteria. The life-threatening nature of this condition requires treatment to be initiated with broad spectrum antimicrobial drugs pending antimicrobial susceptibility testing. Potentiated sulphonamides, for example, trimethoprim combined with sulfadiazine, could be clinically relevant options but their pharmacokinetics in the neonatal foal are unknown.
OBJECTIVES
To describe the plasma disposition of trimethoprim and sulfadiazine in neonatal foals and to relate the results to patterns in the minimum inhibitory concentration (MIC) for Escherichia coli, a recognized pathogen in neonatal foal sepsis.
METHOD
A total of five doses of trimethoprim (2.5 mg/kg) and sulfadiazine (12.5 mg/kg) were administered intravenously every 12 h to eight neonatal foals that were 3 days old at inclusion. A non-linear mixed effects model was fitted to the trimethoprim and sulfadiazine experimental data. The 24 h area under the free plasma trimethoprim and sulfadiazine concentration-time curves (fAUC) and the pharmacokinetic/pharmacodynamik (PK/PD)-index fAUC/MIC was calculated to evaluate the potential clinical benefits of the administered dose.
RESULTS
For trimethoprim, the typical values were 1.99 L/kg, 0.33 L/h·kg and 4.2 h for the apparent volume of distribution, clearance and terminal half-life, respectively. The 24 h fAUC for trimethoprim was 11.3 μg·h/ml (7.2-15.2) and the fAUC/MIC ratio for E. coli was 23 (16.4-29.2) (population mean (range)). For sulfadiazine, the typical values were 0.61 L/kg, 0.09 L/h·kg and 5.3 h for the apparent volume of distribution, clearance and terminal half-life, respectively. The 24 h fAUC for sulfadiazine was 246.8 μg·h/ml (175.6-335.4).
CONCLUSION
For trimethoprim, the plasma exposure is insufficient in some foals to successfully treat bacterial infections with an MIC-value of 0.5 μg/ml using the studied dosing regimen.
Topics: Administration, Intravenous; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Escherichia coli; Gram-Negative Bacteria; Gram-Positive Bacteria; Horses; Sulfadiazine; Trimethoprim
PubMed: 35152563
DOI: 10.1002/vms3.763