Understanding and preventing drug interactions in elderly patients

Anticonvulsant effect of (±) citronellal possibly through the GABAergic and voltage-gated sodium channel receptor interaction pathways: In vivo and in silico studies

This study aimed to investigate the anticonvulsant effects of citronellal (CIT) and possible underlying mechanisms through an isoniazid (INH)-induced seizure (convulsion) via in vivo and in silico studies. For this, convulsions were induced by the oral administration of INH (300 mg/kg) to the mice. The animals were treated orally with different doses of CIT (50, 100, and 200 mg/kg). Vehicle served as a negative control (NC), while diazepam (DZP) (2 mg/kg) and carbamazepine (CAR) (80 mg/kg) were provided (p.o.) as positive controls (PC). A combination therapy of CIT (middle dose) with DZP and CAR was also given to two separate groups of animals to estimate the synergistic or antagonistic effects. Molecular docking and visualization of ligand-receptor interactions are also estimated through different computational tools. The results of the in vivo study showed that CIT dose-dependently significantly (p < 0.05) exhibited a higher onset of seizures while reducing the frequency and duration of seizures in mice compared to the NC group. Besides these, in combination therapy, CIT significantly antagonized the activity of CAR and DZP, leading to a reduction in the onset of seizures and an increase in their frequency and duration compared to treatment with CAR and DZP alone. Additionally, molecular docking revealed that the CIT exhibited a moderate binding affinity (-5.8 kcal/mol) towards the GABAA receptor and a relative binding affinity (-5.3 kcal/mol) towards the voltage-gated sodium channel receptor by forming several bonds. In conclusion, CIT showed moderate anticonvulsant activity in INH-induced convulsion animals, possibly by enhancing GABAA receptor activity and inhibiting the voltage-gated sodium channel receptor.

Clinical pharmacokinetics and drug-drug interactions of tyrosine-kinase inhibitors in chronic myeloid leukemia: A clinical perspective

In the past decade, numerous tyrosine kinase inhibitors (TKIs) have been introduced in the treatment of chronic myeloid leukemia. Given the significant interpatient variability in TKIs pharmacokinetics, potential drug-drug interactions (DDIs) can greatly impact patient therapy. This review aims to discuss the pharmacokinetic characteristics of TKIs, specifically focusing on their absorption, distribution, metabolism, and excretion profiles. Additionally, it provides a comprehensive overview of the utilization of TKIs in special populations such as the elderly, children, and patients with liver or kidney dysfunction. We also highlight known or suspected DDIs between TKIs and other drugs, highlighting various clinically relevant interactions. Moreover, specific recommendations are provided to guide haemato-oncologists, oncologists, and clinical pharmacists in managing DDIs during TKI treatment in daily clinical practice.

Changing Trends Towards Herbal Supplements: An Insight into Safety and Herb-drug Interaction

Herbs have been used as sustenance and medicine for a very long time, often in conjunction with other prescribed medications. Even though they are thought to be natural and secure, many of these herbs can interact with other medications and cause potentially dangerous adverse effects or decrease the benefits of the medication. The complex and diverse pharmacological functions carried out by the active ingredients in herbs unavoidably alter the pharmacokinetics of chemical drugs when administered in vivo. Drug transporter expression has a direct impact on how medications are absorbed, distributed, metabolized, and excreted in living organisms. Changes in substrate pharmacokinetics can affect the effectiveness and toxicity of a drug when the active ingredients of a herb inhibit or stimulate the expression of transporters. By reviewing published clinical and preclinical studies, this review aims to raise awareness of herbdrug interactions and discuss their evidence-based mechanisms and clinical consequences. More clinical information on herb-drug interactions is required to make choices regarding patient safety as the incidence and severity of herb-drug interactions are rising due to an increase in the use of herbal preparations globally.This review seeks to increase understanding of herb-drug interactions and explore their evidence-based mechanisms and clinical implications by reviewing published clinical and preclinical studies. The incidence and severity of herb-drug interactions are on the rise due to an increase in the use of herbal preparations worldwide, necessitating the need for more clinical data on these interactions in order to make decisions regarding patient safety. Healthcare workers and patients will become more alert to potential interactions as their knowledge of pharmacokinetic herb-drug interactions grows. The study's objective is to raise readers' awareness of possible interactions between herbal supplements and prescription medications who regularly take them.

Drug-drug interactions and the risk of adverse drug reaction-related hospital admissions in the older population

AIMS

The aims of this study were to estimate potentially clinically important drug-drug interaction (DDI) prevalence, and the average causal effect of DDI exposure on adverse drug reaction (ADR)-related hospital admission, and to examine differences in health-related quality of life (HRQoL) and length of stay (LOS) per DDI exposure in an older (≥65 years) population acutely hospitalized.

METHODS

This was a cross-sectional study conducted among 798 older individuals acutely admitted to hospital in Ireland between 2016 and 2017. Medication (current/recently discontinued/over-the-counter) and clinical data (e.g., creatinine clearance) were available. DDIs were identified using the British National Formulary (BNF) and Stockley's Drug Interactions. Causal inference models for DDI exposure on ADR-related hospital admission were developed using directed acyclic graphs. Multivariable logistic regression was used to estimate the average causal effect. Differences in HRQoL (EQ-5D) and LOS per DDI exposure were examined non-parametrically. DDI prevalence, adjusted odds ratios (aOR), and 95% confidence intervals (CIs) are reported.

RESULTS

A total of 782 (98.0%) individuals using two or more drugs were included. Mean age was 80.9 (SD ± 7.5) years (range: 66-105); 52.2% were female; and 45.1% (n = 353) had an ADR-related admission. At admission, 316 (40.4% [95% CI: 37.0-43.9]) patients had at least one DDI. The average causal effect of DDI exposure on ADR-related hospital admission was aOR = 1.21 [95% CI: 0.89-1.64]. This was significantly increased by exposure to: DDIs which increase bleeding risk (aOR = 2.00 [1.26-3.12]); aspirin-warfarin (aOR = 2.78 [1.37-5.65]); and esomeprazole-escitalopram (aOR = 3.22 [1.13-10.25]. DDI-exposed patients had lower HRQoL (mean EQ-5D = 0.49 [±0.39]) compared those non-DDI-exposed (mean EQ-5D = 0.57 [±0.41]), (P = .03); and greater median LOS in hospital (8 [IQR5-16]days) compared those non-DDI-exposed (7 [IQR 4-14] days),(P = .04).

CONCLUSIONS

Potentially clinically important DDIs carry an increased average causal effect on ADR-related admission, significantly (two-fold) by exposure to DDIs that increase bleeding risk, which should be targeted for medicine optimization.

An examination of cannabis-related information typically asked by consumers at retail cannabis locations: A Canadian survey of budtenders and managers

Background

Since cannabis has been legalized in Canada for medicinal and recreational use, there has been an increased demand on pharmacists for cannabis counselling. The aim of the study was to examine typical questions posed by consumers to managers and budtenders working at licensed recreational cannabis stores in Canada and to assess how often consumers seek unlicensed medical advice to treat various conditions using cannabis.

Methods

An online survey was synthesized, consisting of 22 questions capturing demographics and Likert scale responses to survey questions, and was distributed online across Canada from January to June 2021.

Results

There were 211 survey respondents: 91 budtenders and 120 managers. A total of 87.7% (n = 185) of respondents indicated that they receive questions related to cannabis use for medical purposes and/or perceived medical benefit, with the same number indicating that they have been told by a customer that their physician sent them to obtain a cannabis-containing product for medical purposes. The most common cannabis component asked about in an average day was THC (42% of responses).

Conclusion

An alarming proportion of budtenders and managers in Canada report that they are fielding medical cannabis questions. This situation has the potential to put individuals at risk for drug-drug interactions and drug-disease interactions and to increase unnecessary hospitalizations due to adverse effects.

Prevalence of Drug-Drug Interactions in Older Community-Dwelling Individuals: A Systematic Review and Meta-analysis

BACKGROUND

Drug-drug interactions (DDIs) can lead to medication-related harm, and the older population is at greatest risk. We conducted a systematic review and meta-analysis to estimate DDI prevalence and identify common DDIs in older community-dwelling adults.

METHODS

PubMed and EMBASE were searched for observational studies published between 01/01/2010 and 10/05/2021 reporting DDI prevalence in community-dwelling individuals aged ≥ 65 years. Nursing home and inpatient hospital studies were excluded. Study quality was assessed using the Joanna Briggs Institute critical appraisal tool. Meta-analysis was performed using a random-effects model with logit transformation. Heterogeneity was evaluated using Cochran's Q and I². DDI prevalence and 95% confidence intervals (CIs) are presented. All analyses were performed in R (version 4.1.2).

RESULTS

There were 5144 unique articles identified. Thirty-three studies involving 17,011,291 community-dwelling individuals aged ≥ 65 years met inclusion criteria. Thirty-one studies reported DDI prevalence at the study-participant level, estimates ranged from 0.8% to 90.6%. The pooled DDI prevalence was 28.8% (95% CI 19.3-40.7), with significant heterogeneity (p < 0.10; I² = 100%; tau² = 2.13) largely explained by the different DDI identification methods. Therefore, 26 studies were qualitatively synthesised and seven studies were eligible for separate meta-analyses. In a meta-analysis of three studies (N = 1122) using Micromedex^®, pooled DDI prevalence was 57.8% (95% CI 52.2-63.2; I² = 69.6%, p < 0.01). In a meta-analysis of two studies (N = 809,113) using Lexi-Interact^®, pooled DDI prevalence was 30.3% (95% CI 30.2-30.4; I² = 6.8%). In a meta-analysis of two studies (N = 947) using the 2015 American Geriatrics Society Beers criteria^®, pooled DDI prevalence was 16.6% (95% CI 5.6-40.2; I² = 97.5%, p < 0.01). Common DDIs frequently involved cardiovascular drugs, including ACE inhibitor-potassium-sparing diuretic; amiodarone-digoxin; and amiodarone-warfarin.

CONCLUSIONS

DDIs are prevalent among older community-dwelling individuals; however, the methodology used to estimate these events varies considerably. A standardised methodology is needed to allow meaningful measurement and comparison of DDI prevalence.

Complexity and clinical significance of drug-drug interactions (DDIs) in oncology: challenging issues in the care of patients regarding cancer-associated thrombosis (CAT)

Cancer patients have an increased risk of developing venous thromboembolic events. Anticoagulation management includes prophylactic or therapeutic doses of low molecular weight heparins (LMWHs) or direct oral anticoagulants (DOACs). However, the management of thrombosis in patients with cancer is complex due to various individual and disease-related factors, including drug–drug interactions (DDIs). Furthermore, DDIs may impact both, cancer and venous thrombosis, treatment effectiveness and safety; their relevance is highlighted by the advances in cancer therapeutics. Given that these new oncology drugs are extensively used, more attention should be given to monitoring potential DDIs to minimize risks. Recognition of DDIs is of utmost importance in an era of rapid developments in cancer treatments and introduction of novel treatments and protocols. When managing cancer-associated thrombosis (CAT), the concomitant use of a DOAC and a moderate or strong modulator (inhibitor or inducer) of CYP3A4 or a P-glycoprotein (P-gp) is most likely to be associated with significant DDIs. Therefore, LMWHs remain the first-line option for the long-term management of CAT under these circumstances and physicians must consider utilizing LMWHs as first line. This review describes the risk of DDIs and their potential impact and outcomes in patients with cancer associated thrombosis (CAT) receiving anticoagulation.

Time-Trends of Drug-Drug Interactions among Elderly Outpatients in the Piedmont Region (Italy): A Population-Based Study

Adverse drug reactions (ADRs) are a major health problem in the primary care setting, particularly among the elderly population. While the high frequency of ADRs in the elderly has several causes, a major and common determinant is polypharmacy, which can in turn increase the risk of drug-drug interactions (DDIs). In this paper, we analyzed the drugs prescriptions dispensed to elderly outpatients, to assess changes in the prevalence of selected DDIs in the period 2013−2019. Overall, about 15% of the patients aged >65 years were poly-treated. Among them, a decreasing trend in prevalence was observed for the majority of DDIs during the study period. This trend was particularly noticeable for DDIs involving fluoroquinolones and vitamin K antagonists, where a sharp reduction of over 40% was observed. On the opposite, a small increase in prevalence was observed for the association of antidiabetics and beta-blocking agents and for that of clopidogrel and PPIs. While the occurrence of most of the considered DDIs among poly-treated elderly decreased over time, the prevalence of some of them is still worrying. The complexity of the national drug formularies, as well as the increased number of prescribing actors that are involved, further urges the update of DDI lists to be used to monitor drug appropriateness and reduce avoidable ADRs.

Application of 3D Hepatic Plate-Like Liver Model for Statin-Induced Hepatotoxicity Evaluation

Background: Drug-induced liver injury is one of the main reasons of withdrawals of drugs in postmarketing stages. However, an experimental model(s) which can accurately recapitulates liver functions and reflects the level of drug hepatotoxicity is lack. In this study, we assessed drug hepatotoxicity using a novel three-dimensional hepatic plate-like hydrogel fiber (3D-P) co-culture system.

Methods: During the 28-days culture period, the liver-specific functions, hepatocyte polarity, sensitivity of drug-induced toxicity of 3D-P co-culture system were evaluated with 2D co-culture, collagen sandwich co-culture, 3D hybrid hydrogel fiber co-culture and human primary hepatocytes as controls. High-content imaging and analysis (HCA) methods were used to explore the hepatotoxicity mechanism of five statins.

Results: The 3D-P co-culture system showed enhancing liver-specific functions, cytochrome P450 enzymes (CYPs) metabolic activity and bile excretion, which were considered to result from improved hepatocyte polarity. Three of the statins may cause acute or chronic hepatotoxicity by via different mechanisms, such as cholestatic liver injury.

Conclusion: Our 3D-P co-culture system is characterized by its biomimetic hepatic plate-like structure, long-term stable liver specificity, and prominent bile secretion function, making it applicable for acute/chronic drug hepatotoxicity assessments.

The Prevalence of Polypharmacy and Potential Drug-Drug Interactions among Iranian Cancer Patients: which Patients Were at Risk?

INTRODUCTION

Drug-Drug interactions (DDIs) are one of the considerable consequences of polypharmacy. Due to the influence of polypharmacy and drug interactions on cancer treatment and patients` health outcomes, the present study aimed to determine the prevalence of polypharmacy and potential DDIs among adult cancer patients in Kerman province, southeast of Iran.

METHODS

In this cross-sectional study, 315 cancer patients who referred to Kerman city oncology clinics were assessed in 2018. Data were collected through face-to-face interviews and medical charts were reviewed. Polypharmacy was defined as the use of at least five drugs simultaneously. Potential DDIs were checked using the "Drugs.com" online database. A bivariable and a multivariable logistic regression were used to determine the associated factors of outcome variables, polypharmacy status and potential DDI in SPSS software version 23.

RESULTS

Of 315 cancer patients, 191 patients (60.6%; 95% CI:54.9, 66) used at least five drugs during chemotherapy courses. The prevalence of potential DDIs was 59.6% (n = 140, 95% CI: 53.6-66.0. Experience co-morbid diseases (OR:6.60; 95%CI: 3.82, 11.42; P-value ≤0.0001), and positive metastatic status (OR:2.80; 95%CI: 1.62, 4.82; P-value ≤0.0001) could predict the polypharmacy during chemotherapy courses. Patients who suffered gastrointestinal cancers (OR:5.55; 95%CI: 2.26, 13.62; P-value ≤0.0001) and the number of prescribed or Over The Counter (OTC) drugs (OR:1.29; 95%CI: 1.12, 1.48; P-value <0.0001) predicted the occurrence of potential DDIs among cancer patients.

CONCLUSION

Regarding the high prevalence of polypharmacy and potential drug interactions among Iranian cancer patients during chemotherapy courses, it is advisable for physicians, nurses, and pharmacists to be vigilant to improve prescribing patterns. In addition, with intensive monitoring, alternative treatment strategies can be replaced.

Prevalence and Factors Associated with Potential Drug-Drug Interactions in Older Community-Dwelling Adults: A Prospective Cohort Study

Background

Older patients are at increased risk of drug-drug interactions (DDIs) due to polypharmacy. Cardiovascular and central nervous system (CNS) drugs are commonly implicated in serious DDIs.

Objectives

This study aimed to determine the prevalence and factors associated with potential ‘severe’ cardiovascular and CNS DDIs among older (≥ 70 years) community-dwellers.

Methods

This was a prospective cohort study using linked data from a national pharmacy claims database and waves 1 and 2 of The Irish LongituDinal study on Ageing (TILDA). ‘Severe’ cardiovascular and CNS DDIs were identified using the British National Formulary 77 and Stockley’s Drug Interactions. The prevalence of ‘severe’ DDIs (any DDI vs. none) was calculated. Logistic regression was used to examine the association between sociodemographic, functional ability, and medication-related factors and the risk of DDI exposure between waves 1 and 2.

Results

A total of 1466 patients were included [mean age (standard deviation) = 78 (5.5) years; female n = 795, 54.2%]. In total, 332 community-dwellers aged ≥ 70 years [22.65%, 95% confidence interval (CI) 20.58–24.86] were potentially exposed to at least one ‘severe’ cardiovascular or CNS DDI, with more than half (54.82%) of this cohort dispensed the same DDI for a prolonged time (≥ 3 consecutive claims). Aspirin-warfarin was the most frequently dispensed (co-prescribed) DDI (n = 34, 10.24%, 95% CI 7.39–14.00), followed by atorvastatin-clarithromycin (n = 19, 5.72%, 95% CI 3.64–8.81). Polypharmacy [≥ 10 vs. < 5 drugs, odds ratio (OR) 13.40, 95% CI 8.22–21.85] and depression (depressed vs. not, OR 2.12, 95% CI 1.34–3.34) were significantly associated with these DDIs, after multivariable adjustment.

Conclusion

‘Severe’ cardiovascular and CNS DDIs are prevalent in older community-dwellers in Ireland, and those with polypharmacy and depression are at a significantly increased risk.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40266-021-00898-8.

Adverse Drug Reactions of Acetylcholinesterase Inhibitors in Older People Living with Dementia: A Comprehensive Literature Review

The rising of global geriatric population has contributed to increased prevalence of dementia. Dementia is a neurodegenerative disease, which is characterized by progressive deterioration of cognitive functions, such as judgment, language, memory, attention and visuospatial ability. Dementia not only has profoundly devastating physical and psychological health outcomes, but it also poses a considerable healthcare expenditure and burdens. Acetylcholinesterase inhibitors (AChEIs), or so-called anti-dementia medications, have been developed to delay the progression of neurocognitive disorders and to decrease healthcare needs. AChEIs have been widely prescribed in clinical practice for the treatment of Alzheimer's disease, which account for 70% of dementia. The rising use of AChEIs results in increased adverse drug reactions (ADRs) such as cardiovascular and gastrointestinal adverse effects, resulting from overstimulation of peripheral cholinergic activity and muscarinic receptor activation. Changes in pharmacokinetics (PK), pharmacodynamics (PD) and pharmacogenetics (PGx), and occurrence of drug interactions are said to be major risk factors of ADRs of AChEIs in this population. To date, comprehensive reviews in ADRs of AChEIs have so far been scarcely studied. Therefore, we aimed to recapitulate and update the diverse aspects of AChEIs, including the mechanisms of action, characteristics and risk factors of ADRs, and preventive strategies of their ADRs. The collation of this knowledge is essential to facilitate efforts to reduce ADRs of AChEIs.

[Usefulness of the summary of product characteristics as a tool to improve prescription in elderly patients]

BACKGROUND AND OBJECTIVE

The Drug Technical Data Sheet should contribute to a safe and effective use of medications in the elderly, providing accurate information on the prescription, on the possible benefits or risks of the medications, or failing that, communicating the lack of information on their use in this group. The aim of this article was to quantify the specific information for people over 65 years of age included in the data sheets of the drugs available in Spain, and enables an adequate prescription in this population.

MATERIALS AND METHODS

A multidisciplinary group reviewed all the Technical Data Sheets of drugs approved by the Spanish Agency for Medicines and Health Devices (AEMPS). The quality of the information was classified into 4 categories: information specifically referring to the population over 65 years old; information specifically referring to the population over 80 years old; recommendations not specific to the elderly; and specific information for the elderly.

RESULTS

A total of 1,462 Technical Sheets were reviewed, of which 48% had information regarding prescription in the elderly. Information on the use in patients over 80 years old was present in 1.23% of the sheets. Only 6.83% of all the sheets reviewed included specific recommendations for the elderly.

CONCLUSIONS

There is little specific information regarding prescription in the elderly in the technical data sheets of drugs prescribed/sold in Spain. To improve knowledge in this field, data must be provided in the sheets that are based on the scientific literature, clinical trials for the elderly, or pharmacovigilance studies focused on this population.

High Risk of Drug-drug interactions among Hospitalized Patients with kidney Diseases at a Nigerian Teaching Hospital: A Call for Action

Background

Potential drug-drug interactions (DDIs) are increasingly common in clinical practice, especially among individuals with chronic conditions, such as chronic kidney dysfunction. However, data relating to DDIs among chronically ill patients are limited in Nigeria. We, therefore, investigated the prevalence and pattern of DDIs among patients with kidney diseases on admission at a tertiary hospital in Lagos, Nigeria.

Materials and Methods

This was a prospective observational study involving 61 adults with kidney diseases and on admission in medical wards of the study center, over a 3-month period. Data extractions were with a purposefully designed pro forma to extract relevant data on demographic, clinical, and dosing regimens of the prescribed drugs for individual patients. Potential DDIs were identified, and their severity was rated using the MICROMEDEX^® software database (IBM^® Watson-Truven Health Analytics), which is available online with limited access.

Results

Of the 61 patients evaluated, majority were males (34; 55.7%), were elderly (26; 42.6%), and had chronic kidney disease Stage 3 (40; 65.5%). The most common cause of kidney disease was hypertension (20; 32.8%). Out of the 542 prescriptions received by the patients, potential DDI was observed in 508 (93.7%) prescriptions. Clinically significant drug interactions (CSDIs) were detected in 486 (85.7%) prescriptions. Pharmacodynamic DDIs (466; 91.7%) were the most common. Pill burden exceeding 25 pills/day was present in nine (14.8%) patients. The severities of the potential DDIs were major (135; 24.9%), moderate (333; 61.4%), and minor (38; 7.1%). Only two different potential DDIs were rated X (contraindicated).

Conclusion

Exposure to drugs with potential DDIs was very common among patients with kidney diseases. Most of the CSDIs observed were of major severity. The use of DDI checker before prescribing drugs for individuals with kidney diseases could avert clinically significant interactions.

The impact of drug interactions on adverse effects of oral oxycodone in male geriatric patients

WHAT IS KNOWN AND OBJECTIVE

With increased opioid use, drug-drug interactions (DDIs) and associated adverse events are growing among geriatric patients. However, the clinical significance of potential metabolic DDIs associated with opioid use has not been fully evaluated among geriatric patients. Particularly, cytochrome (CYP) P450 enzymes are important in drug metabolism of oxycodone and a black box warning for oxycodone reveals serious risks associated with drug-oxycodone interactions. This study focused on the use of oxycodone in geriatric patients to evaluate its adverse drug reactions (ADRs) and DDIs associated with CYP P450 enzymes.

METHODS

A retrospective cohort study using patients treated at Korea Veterans Hospital was performed. Data from male patients aged 65 years and older who received oxycodone were analysed. Binomial variables describing patient-related characteristics, drug-related characteristics and CYP-mediating drugs were constructed. Associations between these variables and the frequency of ADRs were determined. The odds ratio (OR) and adjusted odds ratio (AOR) were calculated from univariable and multivariable analyses, respectively.

RESULTS AND DISCUSSION

Among 111 patients, 32.4% experienced at least one ADR. The most common ADR was gastrointestinal-related (n = 21), followed by dizziness and drowsiness (n = 8). Use of either CYP2D6 inhibitors or CYP3A4 inhibitors increased the rate of ADRs by 20.4 and 25.4 times, respectively. In the case of patients taking both inhibitors, the adjusted OR was 48.6, and the attributable risk was 97.9%.

WHAT IS NEW AND CONCLUSION

This study suggests that inappropriate combinations of oxycodone with CYP2D6 inhibitors and/or CYP3A4 inhibitors may warrant treatment modification to avoid ADRs in geriatric patients. Clinicians should monitor any signs of ADRs that may reflect DDIs while a geriatric patient is taking oxycodone.

Testosterone Replacement Therapy and the Risk of Hypoglycemia

We report the case of a 45-year-old man with a history of Klinefelter syndrome undergoing testosterone replacement therapy, and with type 2 diabetes treated with metformin with poor metabolic control. When vildagliptin was added to his treatment, he presented hypoglycemia after the testosterone injection. We highlight this not widely reported drug interaction between hypoglycemic agents and testosterone.

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

Polypharmacy is very common in older patients and may be associated with drug-drug interactions. Hepatic cytochrome P450 (notably 3A4 subtype, CYP3A4) is a key enzyme which metabolizes most drugs; P-glycoprotein (P-gp) is a transporter which significantly influences distribution and bioavailability of many drugs. In this study, we assess the prevalence and patterns of potential interactions observed in an hospitalized older cohort (Registro Politerapia Società Italiana di Medicina Interna) exposed to at least two interacting drugs involving CYP3A4 and P-gp at admission, during hospitalization and at discharge. Individuals aged 65 and older (N-4039; mean age 79.2; male 48.1%), hospitalized between 2010 and 2016, were selected. The most common combinations of interacting drugs (relative frequency > 5%) and socio-demographic and clinical factors associated with the interactions were reported. The prevalence of interactions for CYP3A4 was 7.9% on admission, 10.3% during the stay and 10.7% at discharge; the corresponding figures for P-gp interactions were 2.2%, 3.8% and 3.8%. The most frequent interactions were amiodarone-statin for CYP3A4 and atorvastatin-verapamil-diltiazem for P-gp. The prevalence of some interactions, mainly those involving cardiovascular drugs, decreased at discharge, whereas that of others, e.g. those involving neuropsychiatric drugs, increased. The strongest factor associated with interactions was polypharmacy (OR 6.7, 95% CI 5.0-9.2). In conclusion, hospital admission is associated with an increased prevalence, but also a changing pattern of interactions concerning CYP3A4 and P-gp in elderly. Educational strategies and appropriate use of dedicated software seem desirable to limit drug interactions and the inherent risk of adverse events in older patients.

Evaluation of Potential Drug-Drug Interactions with Medications Prescribed to Geriatric Patients in a Tertiary Care Hospital

Background and Objectives

The drugs most commonly implicated in major potential interactions are those used in the day-to-day clinical management of elderly patients with chronic diseases. This study is planned to evaluate the profile of drug-drug interactions in the medications prescribed to elderly population and also to identify the possible predictors for potential drug-drug interactions in the elderly.

Methods

This cross-sectional study included patients aged above 60 years with a minimum of two drugs in the prescriptions. Data were collected from medical prescriptions and patients' medical records. The data collected included demographic characteristics such as age, gender, height, weight, educational status, socioeconomic status, medical history, and medications prescribed. The prescriptions were analyzed for the potential drug interactions using Lexi-Interact™ Online, an online software to check drug-drug interactions.

Results

A total of 209 patients were included in the study, among them 104 (49.8%) were males and 105 (50.2%) were females. The mean number of medications received was 6.53 ± 2.15 per prescription. Around 138 (66%) patients received more than six medications. The mean number of potential drug interactions seen in the prescription of these patients was 3.17 ± 2.78. Around 18.2% patients had more than five drug interactions. Major drug interactions were observed in 21.42% of cases. Around 3.02% of drug interactions belonged to risk category X, i.e., to be avoided. Logistic regression analysis showed that age above 70 years was associated with the presence of drug interactions. Increased number of medication was independently associated with the occurrence of drug interactions. The presence of drug interactions was not associated with increased number of comorbidities.

Conclusion

A significant number of potential drug-drug interactions were seen in the prescriptions of elderly patients. Increasing age and polypharmacy were identified as the predictors of potential drug interactions.

Treating Diffuse Large B Cell Lymphoma in the Very Old or Frail Patients

OPINION STATEMENT

R-CHOP has been the standard of care for diffuse large B cell lymphoma (DLBCL), curing approximately 60% of patients for more than 2 decades. However, the optimal treatment of patients who are too frail to tolerate this regimen and/or are not candidates for anthracycline therapy continues to be debated. MInT and GELA trials established addition of rituximab to CHOP in DLBCL but excluded patients older than 80 years. Multiple regimens have been tried with varying success in the very elderly, including R-mini-CHOP, R-mini CEOP, R-split CHOP, pre-phase strategies, and R-GCVP. However, there has not been a randomized trial among these strategies. Although addition of novel agents including ibrutinib, brentuximab vedotin, lenalidomide, and many others on the horizon holds promise in this population, none have been tested in a randomized setting or have results awaited. There is also a lack of a validated and easy to use clinical tool in this population to predict patients who will not tolerate R-CHOP. Identifying patients who will not tolerate R-CHOP early with the help of tools like CGA, along with integrating biology-based treatment (ibrutinib, lenalidomide in activated B cell type DLBCL) is being investigated in this population.

The prevalence of major drug-drug interactions in older adults with cancer and the role of clinical decision support software

OBJECTIVES

Drug-drug interactions (DDIs) represent an escalating concern for older adults attributed to polypharmacy, multi-morbidity and organ dysfunction. Few studies have evaluated the prevalence of major DDIs and the variability between DDI detection software which confuses management.

MATERIALS AND METHODS

Prevalence of major DDIs was examined as a secondary analysis of outpatients aged ≥65 years. Demographic and clinical information was collected from electronic health records including age, sex, race, cancer type, comorbidities, and medications. All DDIs were screened by a clinical pharmacist using Lexi-Interact® and Micromedex®. Major DDIs were defined as Lexi-Interact® category D or X and/or Micromedex® category major or contraindication. Summary statistics of patient characteristics and DDIs were computed.

RESULTS

Our cohort included 142 patients (mean age, 77.7 years; 56% women, 73% Caucasian). The mean medications was 9.8 including 6.7 prescriptions, 2.6 non-prescriptions, and 0.5 herbals. Lexi-Interact® identified 310 major DDIs in 69% of patients (n = 98) with an average of 2.2 DDIs per patient. Micromedex® identified 315 major DDIs in 61% of patients (n = 87) with an average of 2.2 DDIs per patient. DDIs mostly involved opioids, antiplatelets, electrolyte supplements, antiemetics, and antidepressants. Variability existed with the severity rating reporting of the clinical decision support software.

CONCLUSIONS

There was a high prevalence of major DDIs in older adults with cancer. Utilizing clinical decision support software was beneficial for detecting DDIs however, variability existed with severity reporting. Future studies need to identify the relevant DDIs with clinical implications in order to optimize medication safety in this population.

Therapeutic challenges in the mature patient

With the tremendous increase in the proportion of seniors in the global population, geriatric health care has become of greater interest and concern. Increased emphasis on geriatric medicine, along with the growth in the development of age-related skin disorders, has led to particular attention for geriatric, dermatology and dermatopharmacology. An aging population has brought many therapeutic challenges that we need to recognize and overcome by applying geropharmacologic principles. The purpose of this paper is to inform dermatologists of the age-related changes in the pharmacokinetics of common dermatologic drugs, their various interactions potentially occurring in the elderly, and the principles and evidence-based strategies for detection, management, and prevention to improve medication adherence. By implementing these principles and strategies, we can ensure the best and the safest treatment to promote the desired therapeutic outcome and improved quality of life for this fragile subpopulation.

Is Excessive Polypharmacy a Transient or Persistent Phenomenon? A Nationwide Cohort Study in Taiwan

Objectives: Target populations with persistent polypharmacy should be identified prior to implementing strategies against inappropriate medication use, yet limited information regarding such populations is available. The main objectives were to explore the trends of excessive polypharmacy, whether transient or persistent, at the individual level. The secondary objectives were to identify the factors associated with persistently excessive polypharmacy and to estimate the probabilities for repeatedly excessive polypharmacy.

Methods: Retrospective cohort analyses of excessive polypharmacy, defined as prescription of ≥ 10 medicines at an ambulatory visit, from 2001 to 2013 were conducted using a nationally representative claims database in Taiwan. Survival analyses with log-rank test of adult patients with first-time excessive polypharmacy were conducted to predict the probabilities, stratified by age and sex, of having repeatedly excessive polypharmacy.

Results: During the study period, excessive polypharmacy occurred in 5.4% of patients for the first time. Among them, 63.9% had repeatedly excessive polypharmacy and the probabilities were higher in men and old people. Men versus women, and old versus middle-aged and young people had shorter median excessive polypharmacy-free times (9.4 vs. 5.5 months, 5.3 vs. 10.1 and 35.0 months, both p < 0.001). Overall, the probabilities of having no repeatedly excessive polypharmacy within 3 months, 6 months, and 1 year were 59.9, 53.6, and 48.1%, respectively.

Conclusion: Although male and old patients were more likely to have persistently excessive polypharmacy, most cases of excessive polypharmacy were transient or did not re-appear in the short run. Systemic deprescribing measures should be tailored to at-risk groups.

[Anticoagulation in geriatric patients with atrial fibrillation : With what and for whom no more?]

Based on established risk scores, such as the CHA₂DS₂-VASc score, the indications for oral anticoagulation are given for patients over 65 years old with atrial fibrillation and even more so for patients over 75 years old. Before beginning anticoagulation a geriatric assessment for evaluation of the cognitive ability, the activities of daily living and the risk of falling should be made because of the known complications of anticoagulation. Geriatric patients with non-valvular atrial fibrillation (AF) are increasingly being treated with non-vitamin K antagonist oral anticoagulants (NOAC) to prevent ischemic stroke. The European Society for Cardiology (ESC) guidelines for the management of AF recommended NOACs as the preferred treatment and vitamin K antagonists (VKA) only as an alternative option. Meanwhile, apixaban, rivaroxaban, and edoxaban as factor Xa inhibitors and dabigatran as a thrombin inhibitor, are more commonly used in clinical practice in patients with AF. Although, these drugs have pharmacodynamics and pharmacokinetic similarities and are often grouped together, it is important to recognize that the pharmacology and dose regimens differ between compounds. Especially in elderly patients the new drugs have interesting advantages compared to VKA, i. e., less drug-drug interactions with concomitant medication and a more favorable risk-benefit ratio mostly driven by the reduction of bleeding. Treatment of anticoagulation in elderly patients requires weighing the serious risk of stroke with an equally high risk of major bleeding and pharmacoeconomic considerations. The easier practicality of NOACs in routine practice must be emphasized as no international normalized ratio (INR) monitoring is necessary and the interruption of treatment for planned interventions is uncomplicated. A regular monitoring of the indications for NOACs is indispensable (as for all other medications). Especially elderly patients have the greatest benefit from NOAC along with a low renal elimination rate and they should certainly not be withheld from elderly patients who have a clear need for oral anticoagulation.

Comparative pharmacokinetics study of anastrozole after single administration and combination with celecoxib

1. There are numerous investigations demonstrating that the cyclooxygenase-2 (COX-2) inhibitors might enhance the efficiency of anastrozole in breast cancer. Hence, this study was conducted to investigate the comparative pharmacokinetics of anastrozole after single administration and combination with celecoxib. 2. A simple protein precipitation procedure was adopted for the sample preparation with satisfactory extraction recovery for both anastrozole and the internal standard, and then anastrozole was separated and analysed on an ACQUITY BEH UPLC C₁₈ column (50 × 2.0 mm, 1.7 μm, Waters) within 2 min. The calibration curves showed good linarites (r = 0.994). Intra- and inter-day precision were within 4.93 and 13.83%, respectively. The mean extraction recoveries across QC levels were within 91.4%, and the matrix effects were within 94.5%. 3. Results showed that the method was reliable to determine anastrozole in rat plasma. Compared with rats in single administration group, no significant difference was found in the combination group. It is workable to use celecoxib combined with anastrozole in clinical therapy.

Interações medicamentosas potenciais entre medicamentos psicotrópicos dispensados

RESUMO Objetivo Estimar a frequência e caracterizar as interações medicamentosas potenciais entre fármacos psicotrópicos sujeitos a controle especial pela portaria 344/98 da Agência Nacional de Vigilância Sanitária (Anvisa), os quais foram prescritos e dispensados em uma farmácia pública do Município de Cascavel, Paraná. Métodos Estudo retrospectivo com desenho seccional foi realizado em uma Farmácia Pública Municipal. A amostra foi composta por prescrições de medicamentos sujeitos a controle especial, dispensados entre primeiro de julho a 31 de agosto de 2010. As prescrições retidas na farmácia foram analisadas retrospectivamente e as informações, coletadas. As interações medicamentosas potenciais foram identificadas em 824 prescrições. Resultados As prescrições eram na maioria para pacientes do sexo feminino e com idade entre 19 e 59 anos. Em relação à especialidade do prescritor, 30,6% foram prescritas por psiquiatra. Em 77,9% das prescrições identificou-se pelo menos uma interação medicamentosa potencial. Foram descritas 54 diferentes interações medicamentosas potenciais, sendo 34 graves e 20 moderadas. Encontrou-se uma correlação linear entre medicamentos prescritos e interações medicamentosas potenciais (p valor < 0,001). Conclusão O presente estudo identificou uma alta frequência de interações medicamentosas potenciais envolvendo fármacos de controle especial e uma associação positiva entre o número de fármacos prescritos com a maior frequência dessas interações.

Pharmacokinetics of Chemotherapy in the Older Patient

Background

The number of individuals aged 65 years and older is growing rapidly, and the majority of cancers are diagnosed in this age group. Age-related changes in physiology can affect chemotherapy pharmacokinetics and pharmacodynamics in older patients.

Methods

We review the literature regarding the impact of age on the pharmacokinetics of commonly used chemotherapy drugs and discuss age-related changes in physiology and pharmacology that can affect chemotherapy tolerance in older patients.

Results

The data on age-related changes in chemotherapy pharmacokinetics are conflicting. While a few studies report age-related differences in chemotherapy pharmacokinetics, most found no significant difference or subtle differences in pharmacokinetics with aging. A difference in pharmacodynamics was commonly seen, however, with older patients at increased risk of myelosuppression and toxicity from age-related decline in organ function. The majority of these studies were performed in a small cohort of patients, thus limiting the generalizability of these results.

Conclusions

Additional studies are needed to address the pharmacokinetics and pharmacodynamics of cancer therapies in the older patient. Multicenter pharmacokinetic studies of adequate sample size, which include a thorough evaluation of physiologic factors and geriatric assessment parameters, would provide further insight into the factors affecting treatment tolerance. These studies would also help to guide appropriate chemotherapy dosing and interventions in order to maximize efficacy and minimize toxicity in the older patient.

Prevalence and Determinants of the Use of Lipid-Lowering Agents in a Population of Older Hospitalized Patients: the Findings from the REPOSI (REgistro POliterapie Società Italiana di Medicina Interna) Study

BACKGROUND

Older patients are prone to multimorbidity and polypharmacy, with an inherent risk of adverse events and drug interactions. To the best of our knowledge, available information on the appropriateness of lipid-lowering treatment is extremely limited.

AIM

The aim of the present study was to quantify and characterize lipid-lowering drug use in a population of complex in-hospital older patients.

METHODS

We analyzed data from 87 units of internal medicine or geriatric medicine in the REPOSI (Registro Politerapie della Società Italiana di Medicina Interna) study, with reference to the 2010 and 2012 patient cohorts. Lipid-lowering drug use was closely correlated with the clinical profiles, including multimorbidity markers and polypharmacy.

RESULTS

2171 patients aged >65 years were enrolled (1057 males, 1114 females, mean age 78.6 years). The patients treated with lipid-lowering drugs amounted to 508 subjects (23.4%), with no gender difference. Atorvastatin (39.3%) and simvastatin (34.0%) were the most widely used statin drugs. Likelihood of treatment was associated with polypharmacy (≥5 drugs) and with higher Cumulative Illness Rating Scale (CIRS) score. At logistic regression analysis, the presence of coronary heart disease, peripheral vascular disease, and hypertension were significantly correlated with lipid-lowering drug use, whereas age showed an inverse correlation. Diabetes was not associated with drug treatment.

CONCLUSIONS

In this in-hospital cohort, the use of lipid-lowering agents was mainly driven by patients' clinical history, most notably the presence of clinically overt manifestations of atherosclerosis. Increasing age seems to be associated with lower prescription rates. This might be indicative of cautious behavior towards a potentially toxic treatment regimen.

Examining the relationship between therapeutic self-care and adverse events for home care clients in Ontario, Canada: a retrospective cohort study

Background

In an era of a rapidly aging population who requires home care services, clients must possess or develop therapeutic self-care ability in order to manage their health conditions safely in their homes. Therapeutic self-care is the ability to take medications as prescribed and to recognize and manage symptoms that may be experienced, such as pain. The purpose of this research study was to investigate whether therapeutic self-care ability explained variation in the frequency and types of adverse events experienced by home care clients.

Methods

A retrospective cohort design was used, utilizing secondary databases available for Ontario home care clients from the years 2010 to 2012. The data were derived from (1) Health Outcomes for Better Information and Care; (2) Resident Assessment Instrument-Home Care; (3) National Ambulatory Care Reporting System; and (4) Discharge Abstract Database. Descriptive analysis was used to identify the types and prevalence of adverse events experienced by home care clients. Logistic regression analysis was used to examine the association between therapeutic self-care ability and the occurrence of adverse events in home care.

Results

The results indicated that low therapeutic self-care ability was associated with an increase in adverse events. In particular, logistic regression results indicated that low therapeutic self-care ability was associated with an increase in clients experiencing: (1) unplanned hospital visits; (2) a decline in activities of daily living; (3) falls; (4) unintended weight loss, and (5) non-compliance with medication.

Conclusions

This study advances the understanding about the role of therapeutic self-care ability in supporting the safety of home care clients. High levels of therapeutic self-care ability can be a protective factor against the occurrence of adverse events among home care clients. A clear understanding of the nature of the relationship between therapeutic self-care ability and adverse events helps to pinpoint the areas of home care service delivery required to improve clients’ health and functioning. Such knowledge is vital for informing health care leaders about effective strategies that promote therapeutic self-care, as well as providing evidence for policy formulation in relation to risk mitigation in home care.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-017-2103-9) contains supplementary material, which is available to authorized users.

Polypharmacotherapy and blood products as risk factors for venous thromboembolism in postsurgical patients: a case-control study

Background After surgical procedures, patients are at high risk of developing venous thromboembolism, clinically manifested as deep vein thrombosis (DVT) or pulmonary embolism (PE). Objective To evaluate the influence of polypharmacotherapy, comorbidity, drug treatments, packed red blood cells application, adequacy of thromboprophylaxis, and patient characteristics on the occurrence of DVT or PE in postsurgical patients. Setting The surgical department at Murska Sobota General Hospital, Slovenia. Methods In this retrospective case control study, the records of 286 surgical patients were analysed: DVT or PE group (n = 144) and control group (n = 142). The number of prescribed drugs and drug-drug interactions were reviewed, together with prescription of low-molecular-weight heparins. The odds ratios (OR) of risk factors for DVT or PE were calculated using a multivariable logistic regression model. Main outcome measure Risk factors assessment for the occurrence of DVT or PE in surgical patients. Results Polypharmacotherapy (OR 2.02, 95% CI 1.03-3.96, p = 0.040) and packed red blood cells application (OR 3.44, 95% CI 1.46-8.10, p = 0.005) were associated with an increased risk of PE or DVT after surgery. Inadequate thromboprophylaxis with low-molecular-weight heparins significantly increased the likelihood of DVT or PE (OR 2.50, 95% CI 1.41-4.43, p = 0.002). There were no differences between the groups concerning the treatment with nonsteroidal anti-inflammatory drugs, benzodiazepines or antipsychotics. Conclusions Patients with polypharmacotherapy and patients receiving red blood cells should be monitored more closely after surgery as they are more likely to develop DVT or PE.

[Safety of antirheumatic drug treatment in the elderly]

Mainly due to the general demographic changes and decreasing mortality in rheumatic diseases based on therapeutic progress, the proportion of older patients treated by rheumatologists is growing. Drug treatment in the elderly, however, harbors certain risks including age-specific pharmacokinetic features and high rates of multimorbidity and polypharmacy resulting in a risk of drug interactions and adherence problems. Nevertheless, older patients suffering from rheumatic diseases ought to be treated with the same intensity and same targets as the younger counterparts. Bearing all these facts in mind it is a balancing act for rheumatologists to find an optimal treatment for the individual elderly patient. Fear of risks should not lead to hesitant use of drugs leaving these patients alone with treatment deficits, as some studies have suggested.

Metoprolol decreases the plasma exposure of metformin via the induction of liver, kidney and muscle uptake in rats

Drug interactions are one of the commonest causes of side effects, particularly in long-term therapy. The aim of the current study was to investigate the possible effects of metoprolol on the pharmacokinetics of metformin in rats and to clarify the mechanism of drug interaction. In this study, rats were treated with metformin alone or in combination with metoprolol. Plasma, urine and tissue concentrations of metformin were determined by HPLC. Western blotting and real-time qPCR were used to evaluate the expression of rOCTs and rMATE1. The results showed that, after single or 7-day repeated administration, the plasma concentrations of metformin in the co-administration group were significantly decreased compared with that in the metformin group. However, the parameter V/F of metformin in the co-administration group was markedly increased compared with that in the metformin group. The hepatic, renal and muscular K_p of metformin were markedly elevated after co-administration with metoprolol. Consistently, metformin uptake in rat kidney slices was significantly induced by metoprolol. In addition, multiple administrations of metoprolol significantly reduced the expression of rMATE1 in rat kidney as well as the urinary excretion of metformin. Importantly, after long-term administration, lactic acid and uric acid levels in the co-administration group were increased by 25% and 26%, respectively, compared with that in the metformin group. These results indicate that metoprolol can decrease the plasma concentration of metformin via the induction of hepatic, renal and muscular uptake, and long-term co-administration of metformin and metoprolol can cause elevated lactic acid and uric acid levels. Copyright © 2016 John Wiley & Sons, Ltd.

Potentially severe drug-drug interactions among older people and associations in assisted living facilities in Finland: a cross-sectional study

OBJECTIVE

This study aims to assess potentially severe class D drug-drug interactions (DDDIs) in residents 65 years or older in assisted living facilities with the use of a Swedish and Finnish drug-drug interaction database (SFINX).

DESIGN

A cross-sectional study of residents in assisted living facilities in Helsinki, Finland.

SETTING

A total of 1327 residents were assessed in this study. Drugs were classified according to the Anatomical Therapeutic Chemical (ATC) classification system and DDDIs were coded according to the SFINX.

MAIN OUTCOME MEASURES

Prevalence of DDDIs, associated factors and 3-year mortality among residents.

RESULTS

Of the participants (mean age was 82.7 years, 78.3% were females), 5.9% (N = 78) are at risk for DDDIs, with a total of 86 interactions. Participants with DDDIs had been prescribed a higher number of drugs (10.8 (SD 3.8) vs. 7.9 (SD 3.7), p < 0.001). A larger proportion of residents with DDDIs suffered from rheumatoid arthritis or osteoarthritis than those not exposed to DDDIs (24.7% vs. 15.4%, p = 0.030). The most frequent DDDIs were related to the concomitant use of potassium with amiloride (N = 12) or spironolactone (N = 12). Carbamazepine (N = 13) and methotrexate (N = 9) treatments were also frequently linked to DDDIs. During the follow-up, no differences in mortality emerged between the participants exposed to DDDIs and the participants not exposed to DDDIs.

CONCLUSIONS

Of the residents in assisted living, 5.9% were exposed to DDDIs associated with the use of a higher number of drugs. Physicians should be trained to find safer alternatives to drugs associated with DDDIs. KEY POINTS   Potentially severe, class D drug-drug interactions (DDDIs) have been defined in the SFINX database as clinically relevant drug interactions that should be avoided.  • Of the residents in assisted living, 5.9% were exposed to DDDIs that were associated with the use of a higher number of drugs.  • The most frequent DDDIs were related to the concomitant use of potassium with amiloride or spironolactone. Carbamazepine and methotrexate were also linked to DDDIs.  • No difference in mortality was observed between residents exposed to DDDIs and residents not exposed to DDDIs.

Potential drug-drug interactions among elderly patients admitted to medical ward of Ayder Referral Hospital, Northern Ethiopia: a cross sectional study

BACKGROUND

The elderly are considered as special population, as they differ from younger adults in terms of comorbidity, polypharmacy, pharmacokinetics, vulnerability to drug-drug interactions and adverse drug reactions. Despite the fact that the elderly patients are at high risk of having drug interaction and potential adverse outcomes, studies in this regard are scarce in resource limited settings like Ethiopia. The aim of this study was to assess the prevalence and determinants of potential drug-drug interaction in elderly patients admitted to medical ward of Ayder Referral Hospital in Northern Ethiopia.

METHODS

A cross sectional study was conducted among elderly inpatients aged 60 years and above. The study was conducted from February to May 2014. Prescribed drugs being taken concurrently for at least 24 h were included and checked for drug-drug interaction using Micromedex® 2.0 online drug reference. Data were analyzed using statistical software, statistical package for social sciences for windows version 20. Logistic regression model was used to analyze factors associated with occurrence of drug interaction. P value of <0.05 was considered statistically significant.

RESULTS

A total of 140 patients were participated in the study. The mean age (±standard deviation) of participants was 68 (±7) years. Majority (61.4 %) of patients were diagnosed with cardiovascular and/or renal diseases. A total of 814 drugs were prescribed with a mean of 6 (±4) medications per patient during a 13 (±9) days of hospital stay. About two-third (62.2 %) of the respondents were exposed to at least one potential drug-drug interaction. Among these 3.6, 32.9 and 25.7 % of patients had taken contraindicated drug combination, at least one major and at least one moderate drug-drug interaction, respectively. Patients with five or more prescribed medications were four times at risk of having drug-drug interaction (P = 0.00; adjusted odds ratio 4.047; 95 % confidence interval 1.867-8.775).

CONCLUSION

Drug-drug interaction in elderly patients was common in this resource limited set-up. Awareness creation and clinical pharmacist involvement in minimizing the risk associated with potentially harmful drug combinations are needed.

Factors associated with quality of life in patients with severe asthma: the impact of pharmacotherapy

OBJECTIVE:

To identify, characterize, and quantify associations of various factors with quality of life (QoL) in patients with asthma, according to the pharmacotherapy employed.

METHODS:

This was a cross-sectional study involving 49 patients (≥ 18 years of age) with severe uncontrolled or refractory asthma treated at a specialized outpatient clinic of the Brazilian Unified Health Care System, regularly using high doses of inhaled corticosteroids (ICs) or other medications, and presenting comorbidities. At a single time point, QoL was assessed with the Asthma Quality of Life Questionnaire (AQLQ). The overall AQLQ score and those of its domains were correlated with demographic variables (gender and age); Asthma Control Questionnaire score; pharmacotherapy (initial IC dose, inhaler devices, and polytherapy); and comorbidities.

RESULTS:

Better AQLQ scores were associated with asthma control-overall (OR = 0.38; 95% CI: 0.004-0.341; p < 0.001), "symptoms" domain (OR = 0.086; 95% CI: 0.016-0.476; p = 0.001), and "emotional function" domain (OR = 0.086; 95% CI: 0.016-0.476; p = 0.001)-and with IC dose ≤ 800 µg-"activity limitation" domain (OR = 0.249; 95% CI: 0.070-0.885; p = 0.029). Worse AQLQ scores were associated with polytherapy-"activity limitation" domain (OR = 3.651; 95% CI: 1.061-12.561; p = 0.036)-and number of comorbidities ≤ 5-"environmental stimuli" domain (OR = 5.042; 95% CI: 1.316-19.317; p = 0.015).

CONCLUSIONS:

Our results, the importance of this issue, and the lack of studies taking pharmacotherapy into consideration warrant longitudinal studies to establish a causal relationship between the identified factors and QoL in asthma patients.

Evaluation of potential drug- drug interactions among Palestinian hemodialysis patients

BACKGROUND

The aims of this study are to find the prevalence of potential drug-drug interactions (DDIs) in patients with Hemodialysis and identify factors associated with these interactions if present.

METHODS

The study was an observational- retrospective cohort study that was conducted in ten hemodialysis units in the West bank, Palestine, between June and August 2015. The data collection form was completed by interviewing the patients in addition to reviewing their medical records. Potential DDIs were reviewed. SPSS program was used for data analysis.

RESULTS

The study included 275 patients, a total of 930 potential interactions were identified in 245 (89.1 %) patients. Patients were prescribed 1-15 drugs with a mean (± SD) of 7.87 ± 2.44, calcium carbonate was the most common drug prescribed. The most common potential interaction in 114 (41.5 %) patients was Calcium Carbonate/Amlodipine followed by Calcium Carbonate/Aspirin in 76 (27.6 %) cases. Most patients (89.9 %) of the patients had one or more comorbid diseases; hypertension, diabetes and gout were the most common. Univariate analysis showed that the number of potential DDIs were related to the number of diseases, the number of prescribed drugs (P value <0.0001) and the age of the patient (P value = 0.015). The results of multiple linear regression showed a significant positive association between number of potential DDIs with the total number of medications (r = 0.242; p < 0.001).

CONCLUSION

The prevalence of potential drug- drug interactions among hemodialysis patients is very common; they are highly expected and depend on the number of drugs taken by the patients. Many of these potential interactions are considered as preventable drug- related problems, so screening for potential interactions and monitoring regularly is highly needed.

Clinically and pharmacologically relevant interactions of antidiabetic drugs

Patients with type 2 diabetes mellitus often require multifactorial pharmacological treatment due to different comorbidities. An increasing number of concomitantly taken medications elevate the risk of the patient experiencing adverse drug effects or drug interactions. Drug interactions can be divided into pharmacokinetic and pharmacodynamic interactions affecting cytochrome (CYP) enzymes, absorption properties, transporter activities and receptor affinities. Furthermore, nutrition, herbal supplements, patient's age and gender are of clinical importance. Relevant drug interactions are predominantly related to sulfonylureas, thiazolidinediones and glinides. Although metformin has a very low interaction potential, caution is advised when drugs that impair renal function are used concomitantly. With the exception of saxagliptin, dipeptidyl peptidase-4 (DPP-4) inhibitors also show a low interaction potential, but all drugs affecting the drug transporter P-glycoprotein should be used with caution. Incretin mimetics and sodium-glucose cotransporter-2 (SGLT-2) inhibitors comprise a very low interaction potential and are therefore recommended as an ideal combination partner from the clinical-pharmacologic point of view.

[New oral anticoagulants for prophylaxis of stroke. Results of an expert conference on practical use in geriatric patients]

Geriatric patients with non-valvular atrial fibrillation (AF) are increasingly being treated with novel oral anticoagulants (NOAC) to prevent ischemic stroke. This article highlights the outcome of an expert meeting on the practical use of NOAC in elderly patients. An interdisciplinary group of experts discussed the current situation of stroke prevention in geriatric patients and its practical management in daily clinical practice. The topic was examined through focused impulse presentations and critical analyses as the basis for the expert consensus. The key issues are summarized in this paper. The European Society of Cardiology (ESC) guidelines from 2012 for the management of patients with non-valvular AF recommend NOAC as the preferred treatment and vitamin K antagonists (VKA) only as an alternative option. Currently, the NOAC factor Xa inhibitors apixaban and rivaroxaban and the thrombin inhibitor dabigatran are more commonly used in clinical practice for patients with AF. Although these drugs have many similarities and are often grouped together it is important to recognize that the pharmacology and dose regimes differ between compounds. Especially n elderly patients NOAC drugs have some advantages compared to VKA, e.g. less drug-drug interactions with concomitant medication and a more favorable risk-benefit ratio mostly driven by the reduction of bleeding. Treatment of anticoagulation in geriatric patients requires weighing the serious risk of stroke against an equally high risk of major bleeding and pharmacoeconomic considerations. Geriatric patients in particular have the greatest benefit from NOAC, which can also be administered in cases of reduced renal function. Regular control of the indications is indispensable, as also for all other medications of the patient. The use of NOAC should certainly not be withheld from geriatric patients who have a clear need for oral anticoagulation.

Pharmacoepidemiologic Methods for Studying the Health Effects of Drug-Drug Interactions

A drug-drug interaction (DDI) occurs when one or more drugs affect the pharmacokinetics (the body's effect on the drug) and/or pharmacodynamics (the drug's effect on the body) of one or more other drugs. Pharmacoepidemiologic studies are the principal way of studying the health effects of potential DDIs. This article discusses aspects of pharmacoepidemiologic research designs that are particularly salient to the design and interpretation of pharmacoepidemiologic studies of DDIs.