{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T16:27:17Z","timestamp":1786724837183,"version":"build-2736575974"},"reference-count":45,"publisher":"Oxford University Press (OUP)","issue":"9","license":[{"start":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T00:00:00Z","timestamp":1785801600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"funder":[{"DOI":"10.13039\/501100000156","name":"Fonds de Recherche du Qu\u00e9bec-Sant\u00e9","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100000156","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100012779","name":"R\u00e9seau Qu\u00e9b\u00e9cois de Recherche sur les M\u00e9dicaments","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100012779","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001805","name":"Canada Foundation for Innovation","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100001805","id-type":"DOI","asserted-by":"publisher"}]},{"name":"CSHP Research and Education Foundation"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,8,4]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Ciprofloxacin is one of the few orally available antibiotics with activity against Pseudomonas aeruginosa. This study developed a population pharmacokinetic (popPK) model for oral ciprofloxacin in older adults and evaluated whether standard regimens achieve the pharmacokinetic\/pharmacodynamic (PK\/PD) target of 24\u2005h area under the concentration\u2013time curve over minimal inhibitory concentration (AUC0-24\/MIC) \u2265\u202f125.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>This was a prospective pilot study in patients \u226575\u2005years taking oral ciprofloxacin at the McGill University Health Centre, Canada. Plasma samples were collected at steady state (peak, mid-interval, trough) and data fitting was performed using NONMEM with stochastic approximation expectation\u2013maximization. Monte Carlo simulations (n\u200a=\u200a1000) assessed the probability of target attainment (PTA) for standard dosing regimens of 250\u2013750\u2005mg q12h across MICs of 0.125\u20132\u2005mg\/L.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Fifteen patients (median age 82\u2005years, weight 75\u2005kg, creatinine clearance 46\u2005mL\/min) contributed 42 plasma concentrations to the analysis. A one-compartment model with first-order absorption and elimination best described the data. Population mean apparent clearance and volume of distribution were 14.3 L\/h and 247 L, respectively (resulting in a 12\u2005h half-life), with high interindividual variability (IIV: 75.2% and 36.0%). The absorption rate constant was fixed to 2.5\u2005h\u22121. No covariate effects were retained in the final model. At the P. aeruginosa clinical MIC breakpoint of 0.5\u2005mg\/L, standard regimens achieved PTAs of 18.7% (250\u2005mg q12h), 56.6% (500\u2005mg q12h), and 76.5% (750\u2005mg q12h).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>This first popPK model for oral ciprofloxacin specifically in older adults demonstrates that simulated standard dosing regimens fail to achieve PK\/PD targets for P. aeruginosa. The large IIV, increased drug exposure and low target attainment support implementation of therapeutic drug monitoring in this population.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/jac\/dkag283","type":"journal-article","created":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T11:38:49Z","timestamp":1785843529000},"source":"Crossref","is-referenced-by-count":0,"title":["Do current oral ciprofloxacin regimens achieve pharmacokinetic\/pharmacodynamic targets within safe exposure limits in older adults with\n                    <i>Pseudomonas aeruginosa<\/i>\n                    infection? A population pharmacokinetic analysis"],"prefix":"10.1093","volume":"81","author":[{"given":"Mehdi","family":"El Hassani","sequence":"first","affiliation":[{"name":"Faculty of Pharmacy, Universit\u00e9 de Montr\u00e9al , Montr\u00e9al ,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2474-2186","authenticated-orcid":false,"given":"Daniel J G","family":"Thirion","sequence":"additional","affiliation":[{"name":"Faculty of Pharmacy, Universit\u00e9 de Montr\u00e9al , Montr\u00e9al ,","place":["Canada"]},{"name":"Department of Pharmacy, McGill University Health Centre , Montr\u00e9al ,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aysenur","family":"Yaliniz","sequence":"additional","affiliation":[{"name":"Faculty of Pharmacy, Universit\u00e9 de Montr\u00e9al , Montr\u00e9al ,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katherine","family":"Desforges","sequence":"additional","affiliation":[{"name":"Faculty of Pharmacy, Universit\u00e9 de Montr\u00e9al , Montr\u00e9al ,","place":["Canada"]},{"name":"Department of Pharmacy, McGill University Health Centre , Montr\u00e9al ,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jos\u00e9e","family":"Verdon","sequence":"additional","affiliation":[{"name":"Department of Medicine, McGill University Health Centre , Montr\u00e9al ,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0783-0624","authenticated-orcid":false,"given":"Emily G","family":"McDonald","sequence":"additional","affiliation":[{"name":"Department of Medicine, McGill University Health Centre , Montr\u00e9al 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