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The OPTIMAL TDM Study: Determining Optimal Beta-lactam Plasma Concentrations Through Therapeutic Drug Monitoring

Completed
Conditions
Therapeutic Drug Monitoring
Imipenem
Efficacy
Piperacillin
Amoxicillin
Cefepime
Beta-lactam Antibiotics
Toxicity
Flucloxacillin
Meropenem
Interventions
Other: The study is observational.
Registration Number
NCT03790631
Lead Sponsor
University of Geneva, Switzerland
Brief Summary

Little is known of beta-lactam antibiotics' true therapeutic plasma concentration range. The aims of this study are to define evidence-based, safe and effective upper and lower limits of the plasma concentrations of imipenem, meropenem, amoxicillin, flucloxacillin, piperacillin, ceftazidime and cefepime in patients at increased risk of serious bacterial infections and currently understudied pharmacokinetics (the critically ill, the elderly, and the immunosuppressed).

This prospective observational study will include adult patients with suspected or confirmed systemic bacterial infection receiving one of the above-named antibiotics and hospitalized in intensive-care, step-down, or hematology-oncology units of the Geneva University Hospitals (HUG).

Eligible patients will be identified via the electronic health record (EHR). Patients receiving traditional intermittent dosing or prolonged infusions will undergo TDM for at least one intermediate (mid-interval) and one trough level at 24 hours (-12 or +48 hours) after the therapy's start. Patients receiving continuous infusions will undergo TDM for at least one steady-state level. Clinical course will be observed for 30 days from the start of the study antibiotic (1st day of study antibiotic =day 1).

The primary outcome is incidence of clinical toxicity through day 30 after start of study antibiotic (as stratified by BL trough concentration). Secondary outcomes are listed below.

Detailed Description

Little is known of beta-lactam antibiotics' true therapeutic plasma concentration range. The aims of this study are to define evidence-based, safe and effective upper and lower limits of the plasma concentrations of imipenem, meropenem, amoxicillin, flucloxacillin, piperacillin, ceftazidime and cefepime in patients at increased risk of serious bacterial infections and currently understudied pharmacokinetics (the critically ill, the elderly, and the immunosuppressed).

This prospective observational study will include adult patients with suspected or confirmed systemic bacterial infection receiving one of the above-named antibiotics and hospitalized in intensive-care, step-down, or hematology-oncology units of the Geneva University Hospitals (HUG).

Eligible patients will be identified via the electronic health record (EHR). Patients receiving traditional intermittent dosing or prolonged infusions will undergo TDM for at least one intermediate (mid-interval) and one trough level at 24 hours (-12 or +48 hours) after the therapy's start. Patients receiving continuous infusions will undergo TDM for at least one steady-state level. Clinical course will be observed for 30 days from the start of the study antibiotic (1st day of study antibiotic =day 1).

The primary outcome is incidence of clinical toxicity through day 30 after start of study antibiotic (as stratified by BL trough concentration). Secondary outcomes are listed below.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
771
Inclusion Criteria
  • Hospitalized patients with suspected or confirmed systemic bacterial infection:
  1. Receiving either imipenem-cilastatin, meropenem, amoxicillin (±clavulanic acid), flucloxacillin, piperacillin-tazobactam, ceftazidime or cefepime
  2. Aged ≥18 years
  3. Requiring intensive or intermediate-intensive (step-down) care OR severely immunosuppressed (see definitions)
Exclusion Criteria
  1. Planned imminent transfer to an outside hospital
  2. Poor prognosis with life expectancy <1 week and/or intended transition to palliative care

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Arm && Interventions
GroupInterventionDescription
flucloxacillin TDMThe study is observational.Adult patients receiving flucloxacillin for suspected or confirmed bacterial infection. TDM will be performed to assess intermediate and trough levels once the patient is at steady-state.
piperacillin TDMThe study is observational.Adult patients receiving piperacillin (with or without tazobactam) for suspected or confirmed bacterial infection. TDM will be performed to assess intermediate and trough levels once the patient is at steady-state.
amoxicillin TDMThe study is observational.Adult patients receiving amoxicillin for suspected or confirmed bacterial infection. TDM will be performed to assess intermediate and trough levels once the patient is at steady-state.
ceftazidime TDMThe study is observational.Adult patients receiving ceftazidime for suspected or confirmed bacterial infection. TDM will be performed to assess intermediate and trough levels once the patient is at steady-state.
meropenem TDMThe study is observational.Adult patients receiving meropenem for suspected or confirmed bacterial infection. TDM will be performed to assess intermediate and trough levels once the patient is at steady-state.
cefepime TDMThe study is observational.Adult patients receiving cefepime for suspected or confirmed bacterial infection. TDM will be performed to assess intermediate and trough levels once the patient is at steady-state.
imipenem TDMThe study is observational.Adult patients receiving imipenem for suspected or confirmed bacterial infection. TDM will be performed to assess intermediate and trough levels once the patient is at steady-state.
Primary Outcome Measures
NameTimeMethod
Incidence of clinical toxicity through day 30 after start of study antibioticday 30 after start of antibiotic

Incidence of clinical toxicity through day 30 after start of study antibiotic (as stratified by BL trough concentration)

Secondary Outcome Measures
NameTimeMethod
The correlation of free versus total flucloxacillin concentrationsday 30

The correlation of free versus total flucloxacillin concentrations (in a subset of patients, free flucloxacillin plasma levels will also be measured and compared to those of total flucloxacillin).

Incidence of clinical toxicity of piperacillin-tazobactam when co-administered with vancomycinday 30

Incidence of clinical toxicity of piperacillin-tazobactam (and other beta-lactam antibiotics) when co-administered with vancomycin

Incidence of emergence of resistanceday 30

Prevalence of emerging resistance to study antibiotics in clinical isolates (from baseline)

Median intermediate and trough plasma concentrations of tazobactamthrough day 30

In a subset of patients receiving piperacillin/tazobactam, median intermediate and trough plasma concentrations of tazobactam (beta-lactamase inhibitor) in proportion to piperacillin in patients receiving piperacillin-tazobactam

clinical response in patients with neutropenic fever: incidence of clinical cure in this subpopulationday 30

Clinical response (as in outcome no. 2) in the subgroup of patients with neutropenic fever at the time of BL therapy. ("Clinical response" is either clinical cure (resolution of symptoms) or clinical failure (lack of improvement in signs and symptoms of infection OR recurrence of signs/symptoms of infection after initial improvement OR death in the 30-day study period considered at least possibly due to the infection).)

30-day mortality attributable to the treated infectionday 30

30-day mortality attributable to the treated infection

30-day all-cause mortalityday 30

30-day all-cause mortality

incidence of reversible toxicityday 30

Proportion of adverse events (AE) that are reversible after discontinuation of the relevant BL antibiotic

Clinical response: incidence of clinical cureday 30

Clinical response to therapy through day 30 will be measured study-wide. "Clinical response" is either clinical cure (resolution of symptoms) or clinical failure (lack of improvement in signs and symptoms of infection OR recurrence of signs/symptoms of infection after initial improvement OR death in the 30-day study period considered at least possibly due to the infection). Where the MIC is unavailable, EUCAST epidemiologic cutoffs (ECOFF) will be used; if no organism is isolated, non-species-related breakpoints for targeted organisms (e.g., Pseudomonas aeruginosa) will be used.

Incidence of Clostridium difficile infectionday 30

Incidence of Clostridium difficile infection

Incidence of undetectable beta-lactam plasma concentrationsday 30

Proportion of patients with undetectable beta-lactam trough and/or intermediate concentrations

Incidence of off-label prescribingday 30

Proportion of patients for whom (a) beta-lactam dosing is "off-label" according to Swiss recommendations and (b) there are no dosing recommendations (e.g., hemofiltration)

Beta-lactam trough concentration/minimal inhibitory concentration (MIC) indexday 1 (±1)

The trough beta-lactam (BL) concentration/minimal inhibitory concentration (MIC) index on day 1 (±1) will be measured in all patients for later correlation analyses with clinical outcomes (clinical success versus failure).

Trial Locations

Locations (1)

Geneva University Hospitals

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Geneva, Switzerland

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