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Aim: To identify older patients’ risk factors for drug-related readmissions and assess the preventability of older patients’ drug-related revisits. Methods: Post-hoc analysis of a randomised clinical trial with patients aged ≥ 65 years at eight wards within four hospitals in Sweden. The primary outcome used to identify risk factors was drug-related readmission within 12 months post-discharge. A Cox proportional hazards model was made with sociodemographic and clinical baseline characteristics. Four hundred trial participants were randomly selected and their revisits (admissions and emergency department visits) were assessed to identify potentially preventable drug-related revisits, related diseases and causes. Results: Among 2,637 patients (median age (interquartile range) 81 (74–87) years), 582 (22%) experienced a drug-related readmission within 12 months. Sixteen risk factors (hazard ratio > 1, p < 0.05) related to age, previous hospital visits, medication use, multimorbidity and cardiovascular, liver, lung and peptic ulcer disease were identified. The 400 patients experienced a total of 522 hospital revisits, of which 85 (16%) were potentially preventable drug-related revisits. The two most prevalent diseases and causes related to preventable revisits were heart failure (n=24, 28%) and chronic obstructive pulmonary disease (n=13, 15%), and inadequate treatment (n=23, 27%) and insufficient or no follow-up (n=22, 26%). Conclusion: Risk factors for drug-related readmissions in older hospitalised patients were age, previous hospital visits, medication use and multiple diseases. Potentially preventable drug-related hospital revisits are common and might be prevented through adequate medication use and follow-up in older patients with cardiovascular or lung disease.

Johanna Sulku,1,2 Christer Janson,3 Håkan Melhus,4 Andrei Malinovschi,5 Björn Ställberg,6 Kristina Bröms,2,6 Marieann Högman,3 Karin Lisspers,6 Margareta Hammarlund-Udenaes,1 Elisabet I Nielsen1 1Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden; 2Centre for Research and Development, Uppsala University/Region Gävleborg, Gävle, Sweden; 3Department of Medical Sciences, Respiratory, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden; 4Department of Medical Sciences, Clinical Pharmacogenomics and Osteoporosis, Uppsala University, Uppsala, Sweden; 5Department of Medical Sciences, Clinical Physiology, Uppsala University, Uppsala, Sweden; 6Department of Public Health and Caring Sciences, Family Medicine and Preventive Medicine, Uppsala University, Uppsala, SwedenCorrespondence: Johanna SulkuDepartment of Pharmaceutical Biosciences, Faculty of Pharmacy, Uppsala University, Box 591, Uppsala SE-751 24, SwedenTel +46 73 635 7075Fax +46 26 531 237Email johanna.sulku@farmbio.uu.sePurpose: Inhaled corticosteroids (ICS) are often more widely prescribed in the treatment of chronic obstructive pulmonary disease (COPD) than what is recommended in the guidelines. The aim of this study was to evaluate the appropriateness of ICS treatment in COPD patients using the algorithm proposed by the International Primary Care Respiratory Group (IPCRG) and to identify factors associated with ICS treatment.Patients and methods: Appropriateness of ICS therapy was studied with respect to concomitant asthma, history of exacerbations and blood eosinophils (B-Eos) in a Swedish cohort of primary and secondary care patients with COPD. Factors associated with ICS were investigated using multivariable logistic regression.Results: Triple treatment was found to be the most common treatment combination, used by 46% of the 561 included patients, and in total 63% were using ICS. When applying the IPCRG algorithm, there was a possible indication for discontinuation of ICS in 55% of the patients with ICS treatment. Of the patients not using ICS, 18% had an indication for starting such treatment. The strongest factors associated with ICS therapy were frequent exacerbations (aOR 8.61, 95% CI 4.06, 20.67), secondary care contacts (aOR 6.99, 95% CI 2.48, 25.28) and very severe airflow limitation (aOR 5.91, 95% CI 1.53, 26.58).Conclusion: More than half of the COPD patients on ICS met the criteria where withdrawal of the treatment could be tried. There was, however, also a subgroup of patients not using ICS for whom there was an indication for starting ICS treatment. Patients using ICS were characterized by more frequent exacerbations and lower lung function.Keywords: ICS, pharmacological management, inappropriate therapy, chronic obstructive pulmonary disease, IPCRG

The release of inflammatory bacterial products, such as lipopolysaccharide (LPS)/endotoxin, may be increased upon the administration of antibiotics. An improved quantitative understanding of endotoxin release and its relation to antibiotic exposure and bacterial growth/killing may be gained by an integrated analysis of these processes. The aim of this work was to establish a mathematical model that relates Escherichia coli growth/killing dynamics at various cefuroxime concentrations to endotoxin release in vitro Fifty-two time-kill experiments informed bacterial and endotoxin time courses and included both static (0×, 0.5×, 1×, 2×, 10×, and 50× MIC) and dynamic (0×, 15×, and 30× MIC) cefuroxime concentrations. A model for the antibiotic-bacterium interaction was established, and antibiotic-induced bacterial killing followed a sigmoidal Emax relation to the cefuroxime concentration (MIC-specific 50% effective concentration [EC50], maximum antibiotic-induced killing rate [E max] = 3.26 h-1 and γ = 3.37). Endotoxin release was assessed in relation to the bacterial processes of growth, antibiotic-induced bacterial killing, and natural bacterial death and found to be quantitatively related to bacterial growth (0.000292 endotoxin units [EU]/CFU) and antibiotic-induced bacterial killing (0.00636 EU/CFU). Increased release following the administration of a second cefuroxime dose was described by the formation and subsequent antibiotic-induced killing of filaments (0.295 EU/CFU). Release due to growth was instantaneous, while release due to antibiotic-induced killing was delayed (mean transit time of 7.63 h). To conclude, the in vitro release of endotoxin is related to bacterial growth and antibiotic-induced killing, with higher rates of release upon the killing of formed filaments. Endotoxin release over 24 h is lowest when antibiotic exposure rapidly eradicates bacteria, while increased release is predicted to occur when growth and antibiotic-induced killing occur simultaneously.

Lack of effective treatment for multidrug-resistant Klebsiella pneumoniae (MDR-Kp) necessitates finding and optimising combination therapies of old antibiotics. The aims of this study were to quantify the combined effect of polymyxin B and minocycline by building an in silico semi-mechanistic pharmacokinetic/pharmacodynamic (PKPD) model and to predict bacterial kinetics when exposed to the drugs alone and in combination at clinically achievable unbound drug concentration-time profiles. A clinical K. pneumoniae strain resistant to polymyxin B [minimum inhibitory concentration (MIC) = 16 mg/L] and minocycline (MIC = 16 mg/L) was selected for extensive in vitro static time-kill experiments. The strain was exposed to concentrations of 0.0625-48 ? MIC, with seven samples taken per experiment for viable counts during 0-28 h. These observations allowed the development of the PKPD model. The final PKPD model included drug-induced adaptive resistance for both drugs. Both the minocycline-induced bacterial killing and resistance onset rate constants were increased when polymyxin B was co-administered, whereas polymyxin B parameters were unaffected. Predictions at clinically used dosages from the developed PKPD model showed no or limited antibacterial effect with monotherapy, whilst combination therapy kept bacteria below the starting inoculum for 20 h at high dosages [polymyxin B 2.5 mg/kg + 1.5 mg/kg every 12 h (q12h); minocycline 400 mg + 200 mg q12h, loading + maintenance doses]. This study suggests that polymyxin B and minocycline in combination may be of clinical benefit in the treatment of infections by MDR-Kp and for isolates that are non-susceptible to either drug alone. (C) 2020 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Antibiotic combination therapy is used for severe infections caused by multidrug-resistant (MDR) Gram-negative bacteria, yet data regarding which combinations are most effective are lacking. This study aimed to evaluate the in vitro efficacy of polymyxin B in combination with 13 other antibiotics against four clinical strains of MDR Pseudomonas aeruginosa. We evaluated the interactions of polymyxin B in combination with amikacin, aztreonam, cefepime, chloramphenicol, ciprofloxacin, fosfomycin, linezolid, meropenem, minocycline, rifampin, temocillin, thiamphenicol, or trimethoprim by automated time-lapse microscopy using predefined cutoff values indicating inhibition of growth (

Endotoxin, a component of the outer membrane of Gram-negative bacteria, has been extensively studied as a stimulator of the innate immune response. However, the temporal aspects and exposure-response relationship of endotoxin and resulting cytokine induction and tolerance development is less well defined. The aim of this work was to establish an in silico model that simultaneously captures and connects the in vivo time-courses of endotoxin, tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and associated tolerance development. Data from six studies of porcine endotoxemia in anesthetized piglets (n = 116) were combined and used in the analysis, with purified endotoxin (Escherichia coli O111: B4) being infused intravenously for 1-30 h in rates of 0.063-16.0 mu g/kg/h across studies. All data were modelled simultaneously by means of importance sampling in the non-linear mixed effects modelling software NONMEM. The infused endotoxin followed one-compartment disposition and non-linear elimination, and stimulated the production of TNF-alpha to describe the rapid increase in plasma concentration. Tolerance development, observed as declining TNF-alpha concentration with continued infusion of endotoxin, was also driven by endotoxin as a concentration-dependent increase in the potency parameter related to TNF-alpha production (EC50). Production of IL-6 was stimulated by both endotoxin and TNF-a, and four consecutive transit compartments described delayed increase in plasma IL-6. A model which simultaneously account for the time-courses of endotoxin and two immune response markers, the cytokines TNF-alpha and IL-6, as well as the development of endotoxin tolerance, was successfully established. This model-based approach is unique in its description of the time-courses and their interrelation and may be applied within research on immune response to bacterial endotoxin, or in pre-clinical pharmaceutical research when dealing with study design or translational aspects.