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

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

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT03790631
Acronym
OPTIMAL TDM
Enrollment
771
Registered
2018-12-31
Start date
2019-01-14
Completion date
2023-12-31
Last updated
2025-05-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Amoxicillin, Beta-lactam Antibiotics, Cefepime, Ceftazidime, Efficacy, Flucloxacillin, Imipenem, Meropenem, Piperacillin, Therapeutic Drug Monitoring, Toxicity

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.

Interventions

OTHERThe study is observational.

The study is observational.

Sponsors

University Hospital, Geneva
CollaboratorOTHER
University of Geneva, Switzerland
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

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

Design outcomes

Primary

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

Secondary

MeasureTime frameDescription
clinical response in patients with neutropenic fever: incidence of clinical cure in this subpopulationday 30Clinical 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 3030-day mortality attributable to the treated infection
30-day all-cause mortalityday 3030-day all-cause mortality
incidence of reversible toxicityday 30Proportion of adverse events (AE) that are reversible after discontinuation of the relevant BL antibiotic
Incidence of Clostridium difficile infectionday 30Incidence of Clostridium difficile infection
Incidence of clinical toxicity of piperacillin-tazobactam when co-administered with vancomycinday 30Incidence of clinical toxicity of piperacillin-tazobactam (and other beta-lactam antibiotics) when co-administered with vancomycin
Clinical response: incidence of clinical cureday 30Clinical 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 undetectable beta-lactam plasma concentrationsday 30Proportion of patients with undetectable beta-lactam trough and/or intermediate concentrations
Incidence of off-label prescribingday 30Proportion 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)
The correlation of free versus total flucloxacillin concentrationsday 30The 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).
Median intermediate and trough plasma concentrations of tazobactamthrough day 30In 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
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).
Incidence of emergence of resistanceday 30Prevalence of emerging resistance to study antibiotics in clinical isolates (from baseline)

Countries

Switzerland

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 12, 2026