Antibiotic Dosing in Geriatric Patients At the Emergency Department
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Blood sampling, Sputum sample, Hemoculture, Urine sample.
- Who it may be relevant to
- Registry conditions: Elderly Infection, Frailty, Frail Elderly Syndrome, Infection, Bacterial. Basic parameters: from 75 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Belgium
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
In this pilot study, we will investigate whether - with the current dosing regimens, used in the Ghent University Hospital - pharmacodynamic targets regarding beta-lactam antibiotics (more specific Amoxicilline-Clavulanate, Piperacillin-Tazobactam and Temocillin) are attained in frail patients admitted to the geriatric department.
Detailed description
In drug research studies, older people - and especially patients with a geriatric profile or frailty risk - are very frequently excluded. Moreover, drug dosing is often extrapolated from studies in younger adults with failure to consider potential differences in pharmacokinetics (PK) and pharmacodynamics (PD).
Studies on dosing of beta-lactam antibiotics in geriatric or frail patients aged 75 years or older have, to the best of our knowledge, never been performed.
In this pilot study, we will investigate whether - with the current dosing regimens, used in the Ghent University Hospital - pharmacodynamic targets regarding beta-lactam antibiotics (more specific Amoxicilline-Clavulanate, Piperacillin-Tazobactam and Temocillin) are attained in frail patients admitted to the geriatric department.
This monocentric, prospective, observational trial is currently ongoing at the emergency department and geriatric department of the Ghent University Hospital.
Amoxicillin/clavulanic acid 1000/200mg of piperacillin-tazobactam 4000mg or temocillin 2000mg was infused intravenously over 30 minutes using a syringe pump. The standard dosing regimes were used.
An infusion catheter of minimum 18-gauge was placed in the contralateral arm to the arm in which the antibiotic dose was administered. Blood samples were collected from this catheter at first dose and assumed steady state conditions. Steady state was assumed to be reached after minimal 24h (\> 4 doses at four - six hourly interval) of therapy. The goal was to obtain 5 first dose and 5 steady dose samples in every patient.
Material for bacteriological analysis, such as blood cultures, urine samples, sputum, were collected in every patient according to standard care. In case of bacterial growth, MIC's were measured on the reported strains when possible.
Amoxicillin, clavulanic acid, piperacillin, tazobactam and temocillin were measured using a validated ultra-performance liquid chromatographic method with tandem mass spectrometric detection.
Serum creatinine, cystatin C, procalcitonin, infection parameters (CRP, WBC count) and albumin were obtained from standard blood samples performed in these patients at day one and also later on during their therapy.
Three frailty score systems (KATZ, Geriatric 8 - G8, Cumulative Illness Rating Scale - CIRS) were calculated.
Interventions
- Diagnostic test Blood sampling
At predefined time points through a venous catheter already in place. Max. volume to be withdrawn: Maximum 4ml/sample. Maximum 10 samples/patient. A last blood sample will be taken, if necessary, after the end of antibiotic therapy, between day 7 and day 14. Though blood results preferably will be used from available data from tests already done during standard treatment. Samples are collected in lithium-heparin tubes (without gel) and centrifuged immediately (within a maximum of 30 minutes af - Diagnostic test Sputum sample
Bacteriological specimen, such as blood cultures, urine samples, sputum ea., which are usually collected in every patient according to standard care will be retained. If there is bacterial growth, MIC's will be calculated on these strains for study purpose. - Diagnostic test Hemoculture
Bacteriological specimen, such as blood cultures, urine samples, sputum ea., which are usually collected in every patient according to standard care will be retained. If there is bacterial growth, MIC's will be calculated on these strains for study purpose. - Diagnostic test Urine sample
Bacteriological specimen, such as blood cultures, urine samples, sputum ea., which are usually collected in every patient according to standard care will be retained. If there is bacterial growth, MIC's will be calculated on these strains for study purpose.
Primary outcome measures
- Blood concentrations of amoxicillin-clavulanate. [Time frame: Within the first 12 hours (early dose) of treatment and after 24 - 48 hours of treatment (steady state)]
- Blood concentrations of piperacillin-tazobactam. [Time frame: Within the first 12 hours (early dose) of treatment and after 24 - 48 hours of treatment (steady state)]
- Blood concentrations of temocillin. [Time frame: Within the first 12 hours (early dose) of treatment and after 24 - 48 hours of treatment (steady state)]
Secondary outcome measures (4)
- Measured total and unbound concentrations of beta-lactam antibiotics. [Time frame: Within the first 12 hours (early dose) of treatment and after 24 - 48 hours of treatment (steady state)]
- Response to antimicrobial therapy. [Time frame: The end of individual antibiotic therapy with an average of 1 week]
- Achievement of pharmacodynamic targets measured by questionnaire, vital signs, blood results and side effects. [Time frame: The end of individual antibiotic therapy with an average of 1 week]
- Clearance of betalactam antibiotics. [Time frame: Within the first 12 hours (early dose) of treatment and after 24 - 48 hours of treatment (steady state)]
Eligibility criteria
Inclusion criteria
- Patients presenting at the emergency department and later on admitted to the geriatric department
- Patient age 75 years or older
- Patients with geriatric profile according to KATZ scale, G8 screening test or CIRS score.
- Patient receiving antibiotic treatment (amoxicillin-clavulanate, piperacillin-tazobactam)
- Intravenous access available for blood sampling. For measurement of the peak concentration an intravenous access other than the drug infusion line is required.
Exclusion criteria
- Admission to other units than the geriatric department incl. the ICU.
- Absence of informed consent
- Known hypersensitivity to beta-lactam antibiotics
- Patients who received oral amoxicillin-clavulanate prior to admission will not be included in the iv. amoxicillin-clavulanate group.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
Belgium · 1 center
- University Hospital Ghent — Ghent
Publications
- De Clercq A, Desmet T, Boelens J, Somers A, Stove V, Verougstraete N, Brys A, Petrovic M, De Paepe P, De Cock PA. Risk factors for suboptimal target attainment of commonly used ss-lactam antibiotics in older adults: a prospective cohort study. J Antimicrob Chemother. 2026 Feb 2;81(3):dkag048. doi: 10.1093/jac/dkag048. PMID 41692875
Identifiers
NCT: NCT04436991 · EC/2017/1369 (BC-01030)