Drug-drug interactions involving CYP3A4 and p-glycoprotein in hospitalized elderly patients

Pharmacokinetics and pharmacodynamics of drug‒drug interactions in hospitalized older adults treated with direct oral anticoagulants

PURPOSE

Polypharmacy is a frequent situation in older adults that increases the risk of drug-drug interactions (DDIs), both pharmacokinetic (PK) and pharmacodynamic (PD). Direct oral anticoagulants (DOACs) are frequently prescribed in older adults, mainly because of the high prevalence of atrial fibrillation (AF). DOACs are subject to cytochrome P450 3A4 (CYP3A4)- and/or P-glycoprotein (P-gp)-mediated PK DDIs and PD DDIs when co-administered with drugs that interfere with platelet function. The aim of our study was to assess the prevalence of DDIs involving DOACs in older adults and the associated risk factors at admission and discharge.

METHODS

This was a cross-sectional study conducted in an acute geriatric unit between January 1, 2018 and December 31, 2022, including patients over 75 years of age treated with DOACs at admission and/or discharge, for whom a comprehensive collection of co-medications was performed.

RESULTS

From 909 hospitalizations collected, the prevalence of PK DDIs involving DOACs was 16.9% at admission and 20.7% at discharge, and the prevalence of PD DDIs was 20.7% at admission and 20.2% at discharge. Factors associated with DDIs were bleeding history [adjusted odds ratio (ORa) 1.74, 95% confidence interval (CI) 1.13-2.68], number of drugs > 6 (ORa 2.54, 95% CI 1.88-3.46) and reduced dose of DOACs (ORa 0.39, 95% CI 0.28-0.54) at admission and age > 87 years (ORa 0.74, 95% CI 0.55-0.99), number of drugs > 6 (ORa 2.01, 95% CI 1.48-2.72) and reduced dose of DOACs (ORa 0.41, 95% CI 0.30-0.57) at discharge.

CONCLUSION

This study provides an indication of the prevalence of DDIs as well as the profile of DDIs and patients treated with DOACs.

Appropriateness of direct oral anticoagulant prescribing in older subjects with atrial fibrillation discharged from acute medical wards

AIMS

Knowledge on the prescriptive practice of direct oral anticoagulants (DOACs) in older subjects with atrial fibrillation (AF) hospitalized in acute medical wards is limited. This study aimed to evaluate the prevalence and appropriateness of DOAC prescriptions in hospitalized older subjects with AF, discharged from acute medical wards.

METHODS

We analysed a cohort of 609 subjects with AF, aged ≥65 years (mean age 85 years) enrolled from 39 geriatric and nephrology wards in Italy. DOAC prescriptive appropriateness was evaluated according to the summary of product characteristics (smPC), 2019 Beers and STOPP criteria, and drug-drug interactions (DDIs).

RESULTS

At hospital discharge, 33% of patients with AF were prescribed with DOAC, 26% with vitamin-K antagonist, while 41% did not receive any anticoagulant. Among subjects on DOAC therapy, 31% presented a violation of the smPC criteria (mainly underdosage-17%), while 48% and 18% presented a Beers/STOPP inappropriate prescription, or a DDI, respectively. Older age, lower body mass index (BMI), cancer and higher estimated glomerular filtration rate (eGFR) were independently associated with DOAC underdosage or missed prescription (age: adjusted odds ratio [aOR] 1.06, 95% confidence interval [95% CI] 1.00-1.12 for underdosage; eGFR: aOR 1.04, 95% CI 1.02-1.07 for underdosage; BMI: aOR 0.95, 95% CI 0.91-0.99 for missed prescription; cancer: aOR 1.93, 95% CI 1.19-3.13 for missed prescription).

CONCLUSIONS

This study showed a suboptimal DOAC prescriptive practice in older in-patients, with frequent missed prescription and DOAC underdosage. Contrary to current recommendations, physicians appear overly concerned by bleeding risk in real-life older and frailer subjects. Strategies should be developed to promote appropriate DOAC prescription in the hospital setting.

Prevalence and factors associated with inappropriate dosing of apixaban and rivaroxaban in hospitalized older adults with atrial fibrillation: a cross-sectional study

INTRODUCTION

Atrial fibrillation (AF) is a common condition among older adults, requiring anticoagulation therapy to prevent thromboembolic events. Direct oral anticoagulants (DOACs) are now recommended as first-line therapy for this purpose. Apixaban and rivaroxaban are two direct-factor Xa inhibitors whose dosing is based on various factors (age, weight, creatinine, and creatinine clearance) that can affect the pharmacokinetics of the medication. This study aimed to evaluate factors associated with inappropriate dosing of apixaban or rivaroxaban based on the summary of product characteristics.

METHODS

A retrospective, single-center study included 777 hospitalizations of patients treated with apixaban or rivaroxaban for AF between 1 January 2018 and 31 December 2022. Primary endpoint assessed whether the dose of apixaban or rivaroxaban was within the summary of product characteristics used by European Medicine Agency (EMA).

RESULTS

Inappropriate dosing of apixaban or rivaroxaban is noted for approximately 30% of hospitalizations mostly underdosing. Factors associated with the risk of inappropriate dosing were the presence of cognitive impairment [adjusted odds ratio (OR*) 1.65, 95% confidence interval (CI) 1.19-2.29, p value (p) = 0.002], weight per kilogram increase (OR* 1.03, 95% CI 1.01-1.04, p < 0.0001), and history of bleeding under apixaban or rivaroxaban (OR* 1.94, 95% CI 1.24-3.03, p = 0.003).

CONCLUSION

This study highlighted the high prevalence of inappropriate apixaban or rivaroxaban doses in older adults, particularly underdosing, which increases the risk of thromboembolism.

TICBase: Integrated Resource for Data on Drug and Environmental Chemical Interactions with Mammalian Drug Transporters

Environmental health science seeks to predict how environmental toxins, chemical toxicants, and prescription drugs accumulate and interact within the body. Xenobiotic transporters of the ATP-binding cassette (ABC) and solute carrier (SLC) superfamilies are major determinants of the uptake and disposition of xenobiotics across the kingdoms of life. The goal of this study was to integrate drug and environmental chemical interactions of mammalian ABC and SLC proteins in a centralized, integrative database. We built upon an existing publicly accessible platform-the "TransPortal"-which was updated with novel data and searchable features on transporter-interfering chemicals from manually curated literature data. The integrated resource TransPortal-TICBase (https://transportal.compbio.ucsf.edu) now contains information on 46 different mammalian xenobiotic transporters of the ABC- and SLC-type superfamilies, including 13 newly added rodent and 2 additional human drug transporters, 126 clinical drug-drug interactions, and a more than quadrupled expansion of the initial in vitro chemical interaction data from 1,402 to 6,296 total interactions. Based on our updated database, environmental interference with major human and rodent drug transporters occurs across the ABC- and SLC-type superfamilies, with kinetics indicating that some chemicals, such as the ionic liquid 1-hexylpyridinium chloride and the antiseptic chlorhexidine, can act as strong inhibitors with potencies similar or even higher than pharmacological model inhibitors. The new integrated web portal serves as a central repository of current and emerging data for interactions of prescription drugs and environmental chemicals with human drug transporters. This archive has important implications for predicting adverse drug-drug and drug-environmental chemical interactions and can serve as a reference website for the broader scientific community of clinicians and researchers.

Importance of cytochrome 3A4 and 2D6-mediated drug-drug interactions in oxycodone consumption among older adults hospitalized for hip fracture: a cross-sectional study

Hip fracture is a common injury and represents a major health problem with an increasing incidence. In older adults, opioids such as oxycodone are often preferred to other analgesics such as tramadol because of a lower risk of delirium. Different parameters, such as inhibition of cytochrome P450 (CYP450) 2D6 and/or 3A4, can potentially lead to pharmacokinetic variations of oxycodone representing a risk of adverse drugs effects or lack of drug response. There is a risk of drug-drug interactions involving CYP450 in older adults due to the high prevalence of polypharmacy. This study sought to identify patient characteristics that influence oxycodone administration. A single-center observational study included 355 patients with a hip fracture hospitalized in a geriatric postoperative unit. Composite endpoint based on form, duration, and timing to intake separated patients into three groups: "no oxycodone", "low oxycodone ", and "high oxycodone ". CYP450 interactions were studied based on a composite variable defining the most involved CYP450 pathways between CYP2D6 and CYP3A4. CYP450 interactions with CYP2D6 pathway involved were associated with the risk of "high oxycodone" [odds ratio adjusted on age and the type of hip fracture (OR*) 4.52, 95% confidence interval (CI) 1.39-16.83, p = 0.02)], as well as serum albumin levels (OR* 1.09, 95% CI 1.02-1.17, p = 0.01). Cognitive impairment was negatively associated with the risk of "high oxycodone" (OR* 0.38, 95% CI 0.18-0.77, p = 0.02). This study showed an association between CYP2D6 interactions and higher oxycodone consumption indirectly reflecting the existence of uncontrolled postoperative pain.

Maximizing patient safety when prescribing opioids for pain management

ABSTRACT

Cytochrome P450 enzyme metabolism is altered by environmental and genetic factors, which can affect the efficacy and safety of opioids. This article describes CYP polymorphisms and how pharmacogenetic testing could be used to help clinicians make safer decisions about opioid use in patients.

Assessment of potential drug–drug interactions among outpatients in a tertiary care hospital: focusing on the role of P-glycoprotein and CYP3a4 (retrospective observational study)

Background

Selecting a medicine has a significant impact on the quality of therapy including efficacy and safety. P-glycoprotein and CYP3A4 share several common substrates known as bi-substrates. Both play major role in the pharmacokinetics and pharmacodynamics when over or under expressed.

Objective

The study aimed to assess the Drug–Drug Interaction (DDI) related to P-glycoprotein (P-gp) and Cytochrome P450-3A4 (CYP3A4), to predict their clinical outcomes and also to discover prospective predictors of pDDIs.

Methods

The subjects in this retrospective study ranged in age from 18 to 95 years with polypharmacy prescriptions. Information was gathered through patient medical records. Based on Micromedex and previous literature studies, medications prescribed to the patients were observed for pDDIs according to risk rating scale for drug interactions.

Results

A total of 504 patients (160 males and 344 females) were included in the study. The mean of pDDI seen in the patients was 1.66 ± 1.48 and total 825 pDDIs were discovered. The factors significantly associated with having ≥1 pDDIs included: taking ≥5 medicines (OR 1.747), increased age (OR 1.026) increased comorbidities (OR 1.73).

Conclusion

In prescriptions, a considerable number of probable DDI were discovered. Therefore, careful selection of drugs and identification of mechanisms for DDI is needed to lower the frequency of pDDI.

The Chinese herb Styrax triggers pharmacokinetic herb-drug interactions via inhibiting intestinal CYP3A

Human cytochrome P450 3A4 (hCYP3A4) is a predominant enzyme to trigger clinically relevant drug/herb-drug interactions (DDIs or HDIs). Although a number of herbal medicines have been found with strong anti-hCYP3A4 effects in vitro, the in vivo modulatory effects of herbal medicines on hCYP3A4 and their potential risks to trigger HDIs are rarely investigated. Herein, we demonstrate a case study to efficiently find the herbal medicine(s) with potent hCYP3A4 inhibition in vitro and to accurately assess the potential HDIs risk in vivo. Following screening over 100 herbal medicines, the Chinese herb Styrax was found with the most potent hCYP3A4 inhibition in HLMs. In vitro assays demonstrated that Styrax could potently inhibit mammalian CYP3A in liver and intestinal microsomes from both humans and rats. In vivo pharmacokinetic assays showed that Styrax (i.g., 100 mg/kg) significantly elevated the plasma exposure of two CYP3A-substrate drugs (midazolam and felodipine) when midazolam or felodipine was administered orally. By contrast, the plasma exposure of either midazolam or felodipine was hardly affected by Styrax (i.g.) when the victim drug was administered intravenously. Further investigations demonstrated that seven pentacyclic triterpenoid acids (PTAs) in Styrax were key substances responsible for CYP3A inhibition, while these PTAs could be exposed to intestinal tract at relatively high exposure levels but their exposure levels in rat plasma and liver were extremely low. These findings well explained why Styrax (i.g.) could elevate the plasma exposure of victim drugs only when these agents were orally administrated. Collectively, our findings demonstrate that Styrax can modulate the pharmacokinetic behavior of CYP3A-substrate drugs via inhibiting intestinal CYP3A, which is very helpful for the clinical pharmacologists to better assess the HDIs triggered by Styrax or Styrax-related herbal products.

Potential drug-drug interactions in drug therapy for older adults with chronic coronary syndrome at hospital discharge: A real-world study

Introduction: Polypharmacy are commonly observed among older adults with cardiovascular disease. However, multiple medications lead to increased risk of drug-drug interactions (DDIs). Therefore, identification and prevention actions related to harmful DDIs are expected in older adults. The study aimed to describe the prevalence of potential DDIs (pDDIs) in discharge prescriptions among older adults with chronic coronary syndrome (CCS).

Methods: A single-center cross-sectional study was performed in a tertiary public hospital in Beijing, China. CCS patients aged 65 years and above who were admitted to cardiology wards over a 3-month period and alive at discharge were included. Electronic medical records and discharge prescriptions were reviewed. pDDIs were evaluated through the Lexi-Interact online.

Results: pDDIs were identified in 72.9% of the 402 individuals (n = 293). A total of 864 pDDIs were obtained. 72.1% of patients were found with C DDIs (n = 290) and 20.3% were categorized in D and X DDIs (n = 82). The only X DDI was between cyclosporine and atorvastatin. Under category D, glycemia alterations within antidiabetics and increased chances of bleeding with antithrombotic were the most common. Concomitant use of clopidogrel and calcium channel blockers was a frequent situation within category C, followed by synergic blood pressure lowering agents and increased rosuvastatin concentration induced by clopidogrel.

Conclusion: DDIs exposure was common in older CCS. DDIs screening tools should be introduced to alert potential adverse effects. Prescribers need to rigorously review or modulate therapies to prevent DDI-related adverse outcomes. Clinical pharmacists should be more involved in complex drug regimen management.

Evaluation of commonly used cardiovascular drugs in inhibiting vonoprazan metabolism in vitro and in vivo

As a novel acid-suppressing drug, vonoprazan shows the potential to replace traditional proton-pump inhibitors. With its widespread use, some adverse effects that require further study have emerged due to drug–drug interactions. Our study is the first experiment that evaluated the drug–drug interactions of eleven common cardiovascular drugs that inhibit vonoprazan metabolism in vitro and in vivo. Rat liver microsome incubation and molecular simulation docking were applied to explore the inhibition mechanism. Amlodipine and nifedipine showed inhibitory effects on vonoprazan metabolism in both rat and human liver microsomes in the first evaluation part in vitro. The inhibition mechanism analysis results demonstrated that amlodipine and nifedipine might inhibit the metabolism of vonoprazan by a mixed type of competitive and non-competitive inhibition. However, the pharmacokinetic data of the vonoprazan prototype revealed that amlodipine affected vonoprazan in vivo while nifedipine did not. Thus, more attention should be paid when amlodipine is prescribed with vonoprazan. Furthermore, the changes in its carboxylic acid metabolites MI hinted at a complex situation. Molecular simulation suggested the CYP2B6 enzyme may contribute more to this than CYP3A4, and further inhibitory experiments preliminarily verified this speculation. In conclusion, the use of vonoprazan with cardiovascular drugs, especially amlodipine, should receive particular attention in clinical prescriptions.

Potent Inhibition of Human Cytochrome P450 3A4 by Biflavone Components from Ginkgo Biloba and Selaginella Tamariscina

CYP3A4-mediated Phase I biotransformation is the rate-limiting step of elimination for many commonly used clinically agents. The modulatory effects of herbal medicines on CYP3A4 activity are one of the risk factors affecting the safe use of drug and herbal medicine. In the present study, the inhibitory effects of nearly hundred kinds of herbal medicines against CYP3A4 were evaluated based on a visual high-throughput screening method. Furthermore, biflavone components including bilobetin (7-demethylginkgetin, DGK), ginkgetin (GK), isoginkgetin (IGK), and amentoflavone (AMF) were identified as the main inhibitory components of Ginkgo biloba L. (GB) and Selaginella tamariscina (P. Beauv.) Spring (ST), which displayed very strong inhibitory effects toward CYP3A4. The inhibitory effects of these biflavones on clinical drugs that mainly undergo CYP3A4-dependent metabolism were evaluated. The IC₅₀ of GK toward tamoxifen, gefitinib and ticagrelor were found to be of 0.478 ± 0.003, 0.869 ± 0.001, and 1.61 ± 0.039 μM, respectively. These results suggest the potential pharmacokinetic interactions between the identified biflavones and clinical drugs undergoing CYP3A4-mediated biotransformation. The obtained information is important for guiding the rational use of herbal medicine in combination with synthetic pharmaceuticals.

RDW-based clinical score to predict long-term survival in community-acquired pneumonia: a European derivation and validation study

An excess long-term mortality has been observed in patients who were discharged after a community-acquired pneumonia (CAP), even after adjusting for age and comorbidities. We aimed to derive and validate a clinical score to predict long-term mortality in patients with CAP discharged from a general ward. In this retrospective observational study, we derived a clinical risk score from 315 CAP patients discharged from the Internal Medicine ward of Cuneo Hospital, Italy, in 2015-2016 (derivation cohort), which was validated in a cohort of 276 patients discharged from the pneumology service of the Barakaldo Hospital, Spain, from 2015 to 2017, and from two internal medicine wards at the Turin University and Cuneo Hospital, Italy, in 2017. The main outcome was the 18-month follow-up all-cause death. Cox multivariate analysis was used to identify the predictive variables and develop the clinical risk score in the derivation cohort, which we applied in the validation cohort. In the derivation cohort (median age: 79 years, 54% males, median CURB-65 = 2), 18-month mortality was 32%, and 18% in the validation cohort (median age 76 years, 55% males, median CURB-65 = 2). Cox multivariate analysis identified the red blood cell distribution width (RDW), temperature, altered mental status, and Charlson Comorbidity Index as independent predictors. The derived score showed good discrimination (c-index 0.76, 95% CI 0.70-0.81; and 0.83, 95% CI 0.78-0.87, in the derivation and validation cohort, respectively), and calibration. We derived and validated a simple clinical score including RDW, to predict long-term mortality in patients discharged for CAP from a general ward.

Direct Oral Anticoagulants versus Vitamin K Antagonists in Patients Aged 80 Years and Older

The effectiveness of direct oral anticoagulants (DOAC) is non-inferior to vitamin K antagonists (VKA) to treat atrial fibrillation and venous thromboembolism (VTE). In this cross-sectional study, we compared older persons taking DOACs to those taking VKAs. We included ambulatory individuals ≥80 years, affiliated to Mutualité Sociale Agricole of Burgundy, who were refunded for a medical prescription in September 2017. The demographic conditions, registered chronic diseases (RCD), and number and types of prescribed drugs were compared in the DOAC group and VKA group. Of the 3190 included individuals, 1279 (40%) were prescribed DOACs and 1911 (60%) VKAs. Individuals taking VKAs were older than those taking DOACs (87.11 vs. 86.35 years). In the DOAC group, there were more women (51.92% vs. 48.25%) (p = 0.043), less RCD (89.60% vs. 92.73%) (p = 0.002), less VTE (1.80% vs. 6.59%), less severe heart failure (58.09% vs. 67.87%), less severe hypertension (18.22% vs. 23.60%), less severe kidney diseases (1.49% vs. 3.82%), and fewer drugs per prescription (6.15 vs. 6.66) (p < 0.01 for all). The DOAC group were also less likely to be taking angiotensin receptor blockers (10.79% vs. 13.97%), furosemide (40.81% vs. 49.66%) or digoxin (10.32% vs. 13.66%) than the VKA group (p = 0.009, p < 0.001, and p = 0.005). DOACs were less prescribed than VKAs. Individuals taking VKAs were older and had more severe comorbidities and more drugs per prescription than those taking DOACs.

Immunization and Drug Metabolizing Enzymes: Focus on Hepatic Cytochrome P450 3A

OBJECTIVE

Infectious disease emergencies like the 2013-2016 Ebola epidemic and the 2009 influenza and current SARS-CoV-2 pandemics illustrate that vaccines are now given to diverse populations with preexisting pathologies requiring pharmacological management. Many natural biomolecules (steroid hormones, fatty acids, vitamins) and ~60% of prescribed medications are processed by hepatic cytochrome P450 (CYP) 3A4. The objective of this work was to determine the impact of infection and vaccines on drug metabolism.

METHODS

The impact of an adenovirus-based vaccine expressing Ebola glycoprotein (AdEBO) and H1N1 and H3N2 influenza viruses on hepatic CYP 3A4 and associated nuclear receptors was evaluated in human hepatocytes (HC-04 cells) and in mice.

RESULTS

CYP3A activity was suppressed by 55% in mice 24 h after administration of mouse-adapted H1N1, while ˂10% activity remained in HC-04 cells after infection with H1N1 and H3N2 due to global suppression of cellular translation capacity, indicated by reduction (70%, H1N1, 56%, H3N2) of phosphorylated eukaryotic translation initiation factor 4e (eIF4E). AdEBO suppressed CYP3A activity in vivo (44%) and in vitro (26%) 24 hours after infection.

CONCLUSION

As the clinical evaluation of vaccines for SARS-CoV-2 and other global pathogens rise, studies to evaluate the impact of new vaccines and emerging pathogens on CYP3A4 and other metabolic enzymes are warranted to avoid therapeutic failures that could further compromise the public health during infectious disease emergencies.

The multifaceted spectrum of liver cirrhosis in older hospitalised patients: analysis of the REPOSI registry

BACKGROUND

Knowledge on the main clinical and prognostic characteristics of older multimorbid subjects with liver cirrhosis (LC) admitted to acute medical wards is scarce.

OBJECTIVES

To estimate the prevalence of LC among older patients admitted to acute medical wards and to assess the main clinical characteristics of LC along with its association with major clinical outcomes and to explore the possibility that well-distinguished phenotypic profiles of LC have classificatory and prognostic properties.

METHODS

A cohort of 6,193 older subjects hospitalised between 2010 and 2018 and included in the REPOSI registry was analysed.

RESULTS

LC was diagnosed in 315 patients (5%). LC was associated with rehospitalisation (age-sex adjusted hazard ratio, [aHR] 1.44; 95% CI, 1.10-1.88) and with mortality after discharge, independently of all confounders (multiple aHR, 2.1; 95% CI, 1.37-3.22), but not with in-hospital mortality and incident disability. Three main clinical phenotypes of LC patients were recognised: relatively fit subjects (FIT, N = 150), subjects characterised by poor social support (PSS, N = 89) and, finally, subjects with disability and multimorbidity (D&M, N = 76). PSS subjects had an increased incident disability (35% vs 13%, P < 0.05) compared to FIT. D&M patients had a higher mortality (in-hospital: 12% vs 3%/1%, P < 0.01; post-discharge: 41% vs 12%/15%, P < 0.01) and less rehospitalisation (10% vs 32%/34%, P < 0.01) compared to PSS and FIT.

CONCLUSIONS

LC has a relatively low prevalence in older hospitalised subjects but, when present, accounts for worse post-discharge outcomes. Phenotypic analysis unravelled the heterogeneity of LC older population and the association of selected phenotypes with different clinical and prognostic features.

Potentially Inappropriate Medications, Drug-Drug Interactions, and Anticholinergic Burden in Elderly Hospitalized Patients: Does an Association Exist with Post-Discharge Health Outcomes?

BACKGROUND

Polypharmacy is very common in elderly patients and is associated with detrimental outcomes.

OBJECTIVE

Our objective was to evaluate the associations between a large panel of therapy quality indicators, including explicit lists of potentially inappropriate medications (PIMs; Beers criteria and Screening Tool of Older Persons' potentially inappropriate Prescriptions [STOPP] criteria), the Anticholinergic Cognitive Burden (ACB) score, and the number of drug-drug interactions (DDIs), with respect to mortality, rehospitalization, and physical function decline within 3 months from hospital discharge in a cohort of hospitalized elderly patients.

METHODS

We studied 2631 individuals aged ≥ 65 years (median age 79.6; males 48.6%) enrolled in the REPOSI registry. The relationships with mortality and rehospitalization were evaluated using Cox regressions, and relationships with functional status change (as percentage variation of Barthel Index [BI]) were evaluated using mixed linear models.

RESULTS

None of the studied indicators was associated with mortality and rehospitalization. Conversely, only ACB was associated with physical function decline, even after correction for confounders (adjusted mean BI variation of - 7.55%; 95% confidence interval [CI] - 12.37 to - 2.47). The number of medications at discharge, particularly polypharmacy (more than five drugs daily), were the only therapy-related factors associated with mortality (adjusted hazard ratio [aHR] 1.05 [95% CI 1.01-1.10] and 1.70 [95% CI 1.12-2.58], respectively) and rehospitalization (aHR 1.05 [95% CI 1.01-1.08] and 1.31 [95% CI 1.01-1.71], respectively).

CONCLUSION

Polypharmacy, a very simple measure, outperformed sophisticated PIM and DDI indicators of quality of therapy as a correlate of primary clinical outcomes, whereas ACB was associated with physical function decline. Thus, innovative approaches to the definition and research of PIMs and DDIs are eagerly awaited from the perspective of averaging the quantitative burden and qualitative interaction of drugs.

The Prescription of Vitamin K Antagonists in a Very Old Population: A Cross-Sectional Study of 8696 Ambulatory Subjects Aged Over 85 Years

We compared very elderly people taking vitamin K antagonists (VKA) and those not taking VKA (noVKA). Individuals were included in the noVKA group if there was no VKA on their reimbursed prescriptions during the study period. We also compared three subgroups, constituted by VKA type (fluindione, warfarin, or acenocoumarol). We included individuals aged over 85 years, affiliated to Mutualité Sociale Agricole of Burgundy, who were refunded for prescribed VKA in September 2017. The VKA and noVKA groups were compared in terms of demographic conditions, registered chronic diseases (RCD), number of drugs per prescription and cardiovascular medications. The three VKA subgroups were compared for the same items plus laboratory monitoring, novel and refill VKA prescriptions, and prescriber specialty. Of the 8696 included individuals, 1157 (13.30%) were prescribed VKA. Mean age was 90 years. The noVKA group had fewer women (53.67 vs 66.08%), more RCD (93.43 vs. 71.96%) and more drugs per prescription (6.65 vs. 5.18) than the VKA group (all p < 0.01). Except for direct oral anticoagulants and platelet aggregation inhibitors, the VKA group took significantly more cardiovascular medications. The most commonly prescribed VKA was fluindione (59.46%). Mean age was higher in the warfarin (90.42) than in the acenocoumarol (89.83) or fluindione (89.71) subgroups (p < 0.01). No differences were observed for sex (women were predominant) or RCD. 13% of subjects in this population had a VKA prescription. Fluindione was the most commonly prescribed VKA.

Predictors of tacrolimus pharmacokinetic variability: current evidences and future perspectives

INTRODUCTION

In kidney transplantation, tacrolimus (TAC) is at the cornerstone of current immunosuppressive strategies. Though because of its narrow therapeutic index, it is critical to ensure that TAC levels are maintained within this sharp window through reactive adjustments. This would allow maximizing efficiency while limiting drug-associated toxicity. However, TAC high intra- and inter-patient pharmacokinetic (PK) variability makes it more laborious to accurately predict the appropriate dosage required for a given patient.

AREAS COVERED

This review summarizes the state-of-the-art knowledge regarding drug interactions, demographic and pharmacogenetics factors as predictors of TAC PK. We provide a scoring index for each association to grade its relevance and we present practical recommendations, when possible for clinical practice.

EXPERT OPINION

The management of TAC concentration in transplanted kidney patients is as critical as it is challenging. Recommendations based on rigorous scientific evidences are lacking as knowledge of potential predictors remains limited outside of DDIs. Awareness of these limitations should pave the way for studies looking at demographic and pharmacogenetic factors as well as gut microbiota composition in order to promote tailored treatment plans. Therapeutic approaches considering patients' clinical singularities may help allowing to maintain appropriate concentration of TAC.

Changes in Treatment of Very Elderly Patients Six Weeks after Discharge from Geriatrics Department

We assessed the prescriptions of patients hospitalized in a geriatric unit and subsequently discharged. This prospective and observational study was conducted over a two-month period in the geriatrics department (acute and rehabilitation units) of a university hospital. Patients discharged from this department were included over a two-month period. Prescriptions were analyzed at admission and discharge from the geriatrics department (DGD), and six weeks after DGD. We included 209 patients, 63% female, aged 86.8 years. The mean number of medications prescribed was significantly higher at DGD than at admission (7.8 vs. 7.1, p = 0.003). During hospitalization, 1217 prescriptions were changed (average 5.8 medications/patient): 52.8% were initiations, 39.3% were discontinuations, and 7.9% were dose adjustments. A total of 156 of the 209 patients initially enrolled completed the study. Among these patients, 81 (51.9%) had the same prescriptions six weeks after DGD. In univariate analysis, medications were changed more frequently in patients with cognitive impairment (p = 0.04) and in patients for whom the hospital report did not indicate in-hospital modifications (p = 0.007). Multivariate analysis found that six weeks after DGD, there were significantly more drug changes for patients for whom there were changes in prescription during hospitalization (p < 0.001). A total of 169 medications were changed (mean number of medications changed per patient: 1.1): 52.7% discontinuations, 34.3% initiations, and 13% dosage modifications. The drug regimens were often changed during hospitalization in the geriatrics department, and a majority of these changes were maintained six weeks after DGD. Improvements in patient adherence and hospital-general practitioner communication are necessary to promote continuity of care and to optimize patient supervision after hospital discharge.

Potentially inappropriate medication in older participants of the Berlin Aging Study II (BASE-II) - Sex differences and associations with morbidity and medication use

Introduction

Multimorbidity in advanced age and the need for drug treatment may lead to polypharmacy, while pharmacokinetic and pharmacodynamic changes may increase the risk of adverse drug events (ADEs).

Objective

The aim of this study was to determine the proportion of subjects using potentially inappropriate medication (PIM) in a cohort of older and predominantly healthy adults in relation to polypharmacy and morbidity.

Methods

Cross-sectional data were available from 1,382 study participants (median age 69 years, IQR 67–71, 51.3% females) of the Berlin Aging Study II (BASE-II). PIM was classified according to the EU(7)-PIM and German PRISCUS (representing a subset of the former) list. Polypharmacy was defined as the concomitant use of at least five drugs. A morbidity index (MI) largely based on the Charlson Index was applied to evaluate the morbidity burden.

Results

Overall, 24.1% of the participants were affected by polypharmacy. On average, men used 2 (IQR 1–4) and women 3 drugs (IQR 1–5). According to PRISCUS and EU(7)-PIM, 5.9% and 22.6% of participants received at least one PIM, while use was significantly more prevalent in females (25.5%) compared to males (19.6%) considering EU(7)-PIM (p = 0.01). In addition, morbidity in males receiving PIM according to EU(7)-PIM was higher (median MI 1, IQR 1–3) compared to males without PIM use (median MI 1, IQR 0–2, p<0.001).

Conclusion

PIM use occurred more frequently in women than in men, while it was associated with higher morbidity in males. As expected, EU(7)-PIM identifies more subjects as PIM users than the PRISCUS list but further studies are needed to investigate the differential impact of both lists on ADEs and outcome.

Key points

We found PIM use to be associated with a higher number of regular medications and with increased morbidity. Additionally, we detected a higher prevalence of PIM use in females compared to males, suggesting that women and people needing intensive drug treatment are patient groups, who are particularly affected by PIM use.