P Mian1, M J van Esdonk2,3, K T Olkkola4, B C M de Winter5, A Liukas6, I Spriet7, D Tibboel1, M Petrovic8, B C P Koch5, K Allegaert1,9,10. 1. Intensive Care and Department of Paediatric Surgery, Erasmus MC Sophia Children's Hospital, Rotterdam, The Netherlands. 2. Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands. 3. Centre for Human Drug Research, Leiden, The Netherlands. 4. Department of Anaesthesiology, Intensive Care and Pain Medicine University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland. 5. Department of Hospital Pharmacy, Erasmus MC, Rotterdam, The Netherlands. 6. Department of Anaesthesiology, Turku University Hospital, Turku, Finland. 7. Clinical Pharmacology and Pharmacotherapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven and Pharmacy Department, University Hospital Leuven, Leuven, Belgium. 8. Department of Geriatrics, Ghent University Hospital, Ghent, Belgium. 9. Department of Development and Regeneration, KU Leuven, Leuven, Belgium. 10. Department of Paediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, Rotterdam, The Netherlands.
Abstract
AIMS: Paracetamol is the analgesic most used by older people. The physiological changes occurring with ageing influence the pharmacokinetics (PK) of paracetamol and its variability. We performed a population PK-analysis to describe the PK of intravenous (IV) paracetamol in fit older people. Simulations were performed to illustrate target attainment and variability of paracetamol exposure following current dosing regimens (1000 mg every 6 h, every 8 h) using steady-state concentration (Css-mean ) of 10 mg l-1 as target for effective analgesia. METHODS: A population PK-analysis, using NONMEM 7.2, was performed based on 601 concentrations of paracetamol from 30 fit older people (median age 77.3 years, range [61.8-88.5], body weight 79 kg [60-107]). All had received an IV paracetamol dose of 1000 mg (over 15 min) after elective knee surgery. RESULTS: A two-compartment PK-model best described the data. Volume of distribution of paracetamol increased exponentially with body weight. Clearance was not influenced by any covariate. Simulations of the standardized dosing regimens resulted in a Css of 9.2 mg l-1 and 7.2 mg l-1 , for every 6 h and every 8 h respectively. Variability in paracetamol PK resulted in Css above 5.4 and 4.1 mg l-1 , respectively, in 90% of the population and above 15.5 and 11.7, respectively, in 10% at these dosing regimens. CONCLUSIONS: The target concentration was achieved in the average patient with 1000 mg every 6 h, while every 8 h resulted in underdosing for the majority of the population. Furthermore, due to a large (unexplained) interindividual variability in paracetamol PK a relevant proportion of the fit older people remained either under- or over exposed.
AIMS: Paracetamol is the analgesic most used by older people. The physiological changes occurring with ageing influence the pharmacokinetics (PK) of paracetamol and its variability. We performed a population PK-analysis to describe the PK of intravenous (IV) paracetamol in fit older people. Simulations were performed to illustrate target attainment and variability of paracetamol exposure following current dosing regimens (1000 mg every 6 h, every 8 h) using steady-state concentration (Css-mean ) of 10 mg l-1 as target for effective analgesia. METHODS: A population PK-analysis, using NONMEM 7.2, was performed based on 601 concentrations of paracetamol from 30 fit older people (median age 77.3 years, range [61.8-88.5], body weight 79 kg [60-107]). All had received an IV paracetamol dose of 1000 mg (over 15 min) after elective knee surgery. RESULTS: A two-compartment PK-model best described the data. Volume of distribution of paracetamol increased exponentially with body weight. Clearance was not influenced by any covariate. Simulations of the standardized dosing regimens resulted in a Css of 9.2 mg l-1 and 7.2 mg l-1 , for every 6 h and every 8 h respectively. Variability in paracetamol PK resulted in Css above 5.4 and 4.1 mg l-1 , respectively, in 90% of the population and above 15.5 and 11.7, respectively, in 10% at these dosing regimens. CONCLUSIONS: The target concentration was achieved in the average patient with 1000 mg every 6 h, while every 8 h resulted in underdosing for the majority of the population. Furthermore, due to a large (unexplained) interindividual variability in paracetamol PK a relevant proportion of the fit older people remained either under- or over exposed.
Authors: Simon D Harding; Joanna L Sharman; Elena Faccenda; Chris Southan; Adam J Pawson; Sam Ireland; Alasdair J G Gray; Liam Bruce; Stephen P H Alexander; Stephen Anderton; Clare Bryant; Anthony P Davenport; Christian Doerig; Doriano Fabbro; Francesca Levi-Schaffer; Michael Spedding; Jamie A Davies Journal: Nucleic Acids Res Date: 2018-01-04 Impact factor: 16.971
Authors: L T van der Heijden; P Mian; J Hias; B C M de Winter; J Tournoy; L Van der Linden; D Tibboel; K Walgraeve; J Flamaing; B C P Koch; K Allegaert; I Spriet Journal: Drugs Aging Date: 2021-12-17 Impact factor: 3.923
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