Implementation of a clinical pharmacokinetics unit in a third-level hospital
Pdf
European Statement
Clinical Pharmacy Services
Author(s)
María Calvo Arbeloa, Ana Isabel Idoate Grijalba, Mónica Uxue Beunza Sola, Daniel Fresán Restituto, Regina Juanbeltz Zurbano, Diana Tejada Marín , Andrea Rodriguez Esquiroz, Maite Sarobe Carricas
Why was it done?
Patients with special characteristics show a great variability in pharmacokinetic and pharmacodynamics (PK/PD) parameters, which may influence the efficacy and safety of antibiotic therapy.
What was done?
A Clinical Unit of Pharmacokinetics was implemented in the Service of Pharmacy (PS) for therapeutic drug monitoring (TDM) in patients.
How was it done?
1. Selection of drugs to be monitored: Antimicrobials (Vancomycin, amikacin, linezolid and voriconazole), Immunosuppressants (tacrolimus), Antineoplastics (methotrexate) and digoxin.
2. Installation of the Abbottbase Pharmacokinetic System (Pks®) software.
3. Creation in the Computerised Clinical History (CCH) a sheet for collecting anthropometric and pharmacological data and pharmacokinetic interpretation of the results obtained.
4. Creation in CCH of a consultation option for clinicians to request monitoring from the PS.
5. Formative session for clinicians and nurses.
What has been achieved?
To begin with the unit, we selected three drugs: vancomycin, amikacin and voriconazole. The hospital pharmacist or the clinician chose the susceptible patients.
Between December 2021 and September 2022, 171 determinations were made in 73 patients: 134 (78.36%) for vancomycin, 24 (14.06%) for amikacin and 13 (7.60%) for voriconazole. Forty-six (63.01%) patients were men and the mean age was 56.58 (17-97) years- old. Eighteen (24.66%) patients were obese. The mean creatinine level was 0.82 (0.4-2.69) mg/ml and glomerular filtration according to the Cockcroft and Gault formula was 81.16 (23.68-161.98) ml/min/m².
For vancomycin, 45 (88.24%) patients started the treatment with a standard dose of 1000 mg every 12 hours. In first determinations, 27 (52.94%) were under-therapeutic and 20 (42.55%) were overdosed. After modifying the dosage regimen, 35 (74.47%) were in range, 3 (6.38%) under-therapeutic and 13 (27.66%) supra-therapeutic.
In case of amikacin, 17 (85%) patients started with a standard dose (1000 mg every 24 hours) achieving target levels only in one case. All were under-therapeutic. After modifying the dosage regimen, we achieved the objective in all of them.
For voriconazole 3 patients were monitored. In 10 (43.5%) determinations, a change in dosage regimen was suggested due to subtherapeutic levels. All (100%) of the recommendations given by the PS were accepted.
What next?
The implementation of the unit in our hospital shows the usefulness and the need to extend pharmacokinetic monitoring to other medical services and drugs.