Relevant Drug-drug Interactions Research Articles

Detection and management of clinically relevant drug-drug interactions with direct oral anticoagulants: an intervention study in community pharmacies

IntroductionDirect oral anticoagulants (DOACs) are increasingly used and can be involved in clinically relevant drug-drug interactions (DDIs) that increase the risk of major bleeding or thromboembolism. Skilled drug interaction management is essential to ensure safe and effective use of DOACs. In this study, we aimed to investigate the impact of the detection and management of DDIs with DOACs in a real-life community pharmacy setting on the pharmacotherapy of DOAC users. MethodsWe conducted an intervention study in 201 community pharmacies in Belgium. On random days, patients purchasing DOACs or drugs known to interact with them were screened. When a DDI with the DOAC was detected, the pharmacist contacted the prescribing physician to discuss the management of the interaction. A previously developed practice-oriented DDI list accompanied by management plans for ambulatory care was used for both screening and management of the DDIs. ResultsIn total, 751 patients were included, among whom 875 DDIs were identified, primarily pharmacodynamic DDIs (95.7 %). Predominant interacting drug classes included selective serotonin or serotonin and norepinephrine reuptake inhibitors (32.9 %), antiplatelets (30.9 %), and non-steroidal anti-inflammatory drugs (28.9 %). In 43.0 % of DDIs, an intervention was decided upon. At three-month follow-up, proposed pharmacotherapy changes had been implemented in 79.1 % of these DDIs. ConclusionsThis study demonstrates that active screening and management of DDIs with DOACs in community pharmacies, in close collaboration with prescribing physicians, resulted in changes in pharmacotherapy in a substantial number of patients. This may contribute significantly to the safer utilisation of DOACs in high-risk populations.

DeepARV: ensemble deep learning to predict drug-drug interaction of clinical relevance with antiretroviral therapy

Drug-drug interaction (DDI) may result in clinical toxicity or treatment failure of antiretroviral therapy (ARV) or comedications. Despite the high number of possible drug combinations, only a limited number of clinical DDI studies are conducted. Computational prediction of DDIs could provide key evidence for the rational management of complex therapies. Our study aimed to assess the potential of deep learning approaches to predict DDIs of clinical relevance between ARVs and comedications. DDI severity grading between 30,142 drug pairs was extracted from the Liverpool HIV Drug Interaction database. Two feature construction techniques were employed: 1) drug similarity profiles by comparing Morgan fingerprints, and 2) embeddings from SMILES of each drug via ChemBERTa, a transformer-based model. We developed DeepARV-Sim and DeepARV-ChemBERTa to predict four categories of DDI: i) Red: drugs should not be co-administered, ii) Amber: interaction of potential clinical relevance manageable by monitoring/dose adjustment, iii) Yellow: interaction of weak relevance and iv) Green: no expected interaction. The imbalance in the distribution of DDI severity grades was addressed by undersampling and applying ensemble learning. DeepARV-Sim and DeepARV-ChemBERTa predicted clinically relevant DDI between ARVs and comedications with a weighted mean balanced accuracy of 0.729 ± 0.012 and 0.776 ± 0.011, respectively. DeepARV-Sim and DeepARV-ChemBERTa have the potential to leverage molecular structures associated with DDI risks and reduce DDI class imbalance, effectively increasing the predictive ability on clinically relevant DDIs. This approach could be developed for identifying high-risk pairing of drugs, enhancing the screening process, and targeting DDIs to study in clinical drug development.

Medication use among the oldest old in the Faroe Islands-A national cross-sectional study.

Aging is often associated with an increasing number of comorbidities that warrant use of multiple drugs which increases the use of potentially inappropriate medications (PIMs), drug-drug interactions (DDIs) and drug-related problems (DRPs). The aim is to assess the prevalence of polypharmacy, PIMs, DDIs and DRPs among Faroese residents aged ≥90 years. In this population-based cross-sectional study, 494 individuals ≥90 years were invited and 298 (60%) participated. A pharmacist-led medication review was performed based on self-information, electronic patient journal and the Faroese Prescription Registry. The prevalence of polypharmacy was 74% with no sex-difference. Approximately 60% of participants used PIMs, primarily benzodiazepines and proton pump inhibitors, the latter being a frequently implicated medication in DRPs. Opioid use was low compared with other Nordic studies. DRPs were observed for 79% with discrepancies in the medication lists as the most common cause, and DDIs were identified for 47% of participants, mostly moderately clinically relevant DDIs. In conclusion, the medication use among the oldest old Faroese resembled that in other Nordic countries with a high prevalence of polypharmacy and use of PIMs, especially PPIs and benzodiazepines. However, no sex-difference was noted in medication use and the use of opioids was low.

Drug-Drug Interactions of FXI Inhibitors: Clinical Relevance.

Inhibitors of the factor FXI represent a new class of anticoagulant agents that are facing clinical approval for the treatment of acute coronary syndrome (ACS), venous thromboembolism (VTE), and stroke prevention of atrial fibrillation (AF). These new inhibitors include chemical small molecules (asundexian and milvexian), monoclonal antibodies (abelacimab, osocimab, and xisomab), and antisense oligonucleotides (IONIS-FXIRX and fesomersen), and thus, they have very peculiar and different pharmacokinetic and pharmacodynamic properties. Besides their clinical efficacy and safety, based on their pharmacological heterogeneity, the use of these drugs in patients with comorbidities may undergo drug-drug interactions (DDIs) with other concomitant therapies. Although only little clinical evidence is available, it is possible to predict clinically relevant DDI by taking into consideration their pharmacokinetic properties, such as the CYP450-dependent metabolism, the interaction with drug transporters, and/or the route of elimination. These characteristics may be useful to differentiate their use with the direct oral anticoagulant (DOAC) anti -FXa (rivaroxaban, apixaban, edoxaban) and thrombin (dabigatran), whose pharmacokinetics are strongly dependent from P-gp inhibitors/inducers. In the present review, we summarize the current clinical evidence on DDIs of new anti FXI with CYP450/P-gp inhibitors and inducers and indicate potential differences with DOAC anti FXa.

Deep Learning Models Compared to Experimental Variability for the Prediction of CYP3A4 Time-Dependent Inhibition.

Most drugs are mainly metabolized by cytochrome P450 (CYP450), which can lead to drug-drug interactions (DDI). Specifically, time-dependent inhibition (TDI) of CYP3A4 isoenzyme has been associated with clinically relevant DDI. To overcome potential DDI issues, high-throughput in vitro assays were established to assess the TDI of CYP3A4 during the discovery and lead optimization phases. However, in silico machine learning models would enable an earlier and larger-scale assessment of TDI potential liabilities. For CYP inhibition, most modeling efforts have focused on highly imbalanced and small data sets. Moreover, assay variability is rarely considered, which is key to understand the model's quality and suitability for decision-making. In this work, machine learning models were built for the prediction of TDI of CYP3A4, evaluated prospectively, and compared to the variability of the experimental assay. Different modeling strategies were investigated to assess their influence on the model's performance. Through multitask learning, additional data sets were leveraged for model building, coming from public databases, in-house CYP-related assays, or other pharmaceutical companies (federated learning). Apart from the numerical prediction of inactivation rates of CYP3A4 TDI, three-class predictions were carried out, giving a negative (inactivation rate kobs < 0.01 min-1), weak positive (0.01 ≤ kobs ≤ 0.025 min-1), or positive (kobs > 0.025 min-1) output. The final multitask graph neural network model achieved misclassification rates of 8 and 7% for positive and negative TDI, respectively. Importantly, the presented deep learning-based predictions had a similar precision to the reproducibility of in vitro experiments and thus offered great opportunities for drug design, early derisk of DDI potential, and selection of experiments. To facilitate CYP inhibition modeling efforts in the public domain, the developed model was used to annotate ∼16 000 publicly available structures, and a surrogate data set is shared as Supporting Information.

Pharmacotherapeutic Considerations in the Treatment of Nontuberculous Mycobacterial Infections: A Primer for Clinicians.

Nontuberculous mycobacteria (NTM) can cause a variety of infections, including serious pulmonary disease. Treatment encompasses polypharmacy, with a targeted regimen of 2-5 active medications, depending on site of infection, species, and clinical characteristics. Medications may include oral, intravenous, and inhalational routes. Medication acquisition can be challenging for numerous reasons, including investigational status, limited distribution models, and insurance prior authorization. Additionally, monitoring and managing adverse reactions and drug interactions is a unique skill set. While NTM is primarily medically managed, clinicians may not be familiar with the intricacies of medication selection, procurement, and monitoring. This review offers insights into the pharmacotherapeutic considerations of this highly complex disease state, including regimen design, medication acquisition, safety monitoring, relevant drug-drug interactions, and adverse drug reactions.

Drug-Drug Interactions and Actual Harm to Hospitalized Patients: A Multicentre Study Examining the Prevalence Pre- and Post-Electronic Medication System Implementation.

Drug-drug interactions (DDIs) have potential to cause patient harm, including lowering therapeutic efficacy. This study aimed to (i) determine the prevalence of potential DDIs (pDDIs); clinically relevant DDIs (cDDIs), that is, DDIs that could lead to patient harm, taking into account a patient's individual clinical profile, drug effects and severity of potential harmful outcome; and subsequent actual harm among hospitalized patients and (ii) examine the impact of transitioning from paper-based medication charts to electronic medication management (eMM) on DDIs and patient harms. This was a secondary analysis of the control arm of a controlled pre-post study. Patients were randomly selected from three Australian hospitals. Retrospective chart review was conducted before and after the implementation of an eMM system, without accompanying clinical decision support alerts for DDIs. Harm was assessed by an expert panel. Of 1186 patient admissions, 70.1% (n = 831) experienced a pDDI, 42.6% (n = 505) a cDDI and 0.9% (n = 11) an actual harm in hospital. Of 15,860 pDDIs identified, 27.0% (n = 4285) were classified as cDDIs. The median number of pDDIs and cDDIs per 10 drugs were 6 [interquartile range (IQR) 2-13] and 0 (IQR 0-2), respectively. In cases where a cDDI was identified, both drugs were 44% less likely to be co-administered following eMM (adjusted odds ratio 0.56, 95% confidence interval 0.46-0.73). Although most patients experienced a pDDI during their hospital stay, less than one-third of pDDIs were clinically relevant. The low prevalence of harm identified raises questions about the value of incorporating DDI decision support into systems given the potential negative impacts of DDI alerts.

Pharmacist's role in the management of drug-drug interactions caused by nirmatrelvir/ritonavir in COVID-19 oncohematology patients.

New drugs developed for SARS-CoV-2 infection, such as nirmatrelvir/ritonavir (NMV/r), represent a potential for oncohematology patients, but also pose a challenge in managing the potential clinically relevant drug-drug interactions (pDDIs) that may arise. The aim of this study is to assess the frequency, severity, and pharmacist detection of pDDIs. This prospective, observational, study spanned 8 months, involving 42 oncohematology patients prescribed NMV/r in a tertiary-level hospital. A Board Certified oncology pharmacist assessed pDDIs using three databases and made recommendations to prescribing physicians. Linear and logistic regression analyses were employed to explore the relationship between prescribed drugs and pDDIs. Clinically relevant pDDIs were detected in 76.2% of patients, with 18.1% of all medications involved in drug-drug interactions (DDIs). The most common drugs implicated were atorvastatin and imatinib. Micromedex® identified 63.3% of interactions as major severity, while Lexicomp® and University of Liverpool classifications were less restrictive. Pharmacists prevented most DDIs from reaching patients through different interventions, including treatment monitoring (44.2%), discontinuation (36.5%), and dose reduction (17.3%). This study highlights the high prevalence of clinically significant pDDIs in oncohematology patients receiving NMV/r for COVID-19. Pharmacists, as integral members of the healthcare team, played a crucial role in detecting, categorizing, and mitigating these interactions. The results underscore the need for comprehensive studies to evaluate the impact of pharmacist-led interventions in optimizing drug therapy and enhancing patient safety in this vulnerable population.

Drug-drug interaction perpetrators of oxycodone in patients with cancer: frequency and clinical relevance.

Oxycodone is known to have numerous drug-drug interactions (DDIs) that can potentially decrease efficacy or lead to adverse drug reactions (ADRs). However, there is limited research on the frequency of DDIs associated with oxycodone, which is important in optimising pharmacovigilance and the need for additional research on certain DDIs. In this study, the frequency of pharmacologically and clinically relevant DDI perpetrators was studied in patients with cancer. This was a cross-sectional study using hospital pharmacy records of patients with cancer who were prescribed oxycodonebetween September 2021 and September 2022. Medication records of patients prescribed oxycodone during a period of ≥ 5 consecutive days (= oxycodone treatment episodes) were reviewed to identify the concomitant use of pharmacologically relevant perpetrators, based on reference sources (Lexicomp®, Micromedex®, the Dutch Kennisbank and the Dutch Commentaren Medicatiebewaking). The clinical relevance was examined by a clinical pharmacologist and a medical oncologist. Additionally, the frequency of double interactions-concomitant oxycodone use with two CYP3A4 and / or CYP2D6 perpetrators-was studied. Overall, 254 oxycodone treatment episodes were included, of which 227 (89.4%) were found to contain at least one pharmacologically relevant DDI perpetrator. Of these, 210 (82.7%) were considered to be clinically relevant. A total of 80 different pharmacologically relevant perpetrators were identified, with 65 (81.3%) being considered clinically relevant. Double interactions were observed in 21 (8.3%) oxycodone treatment episodes. A high frequency of pharmacologically and clinically relevant perpetrators of oxycodone was observed in our cohort. Moreover, a high number of double interactions involving oxycodone was registered. More intense monitoring of DDIs may be needed to improve medication safety of patients with cancer taking oxycodone.

In vitro and in vivo pharmacokinetics, disposition, and drug-drug interaction potential of tinengotinib (TT-00420), a promising investigational drug for treatment of cholangiocarcinoma and other solid tumors

Early-stage clinical evaluation of tinengotinib (TT-00420) demonstrated encouraging preliminary efficacies in multiple types of refractory cancers, including fibroblast growth factor receptors (FGFR) inhibitors relapsed cholangiocarcinoma (CCA), castrate-resistant prostate cancer (CRPC), and HR+/HER2- breast cancer and triple negative breast cancer (TNBC). To further evaluate drug-like properties of the drug candidate, it is imperative to understand its metabolism and pharmacokinetic properties. This manuscript presented the investigation results of in vitro permeability, plasma protein binding, metabolic stability, metabolite identification, and drug-drug interaction of tinengotinib. Preclinical ADME (absorption, distribution, excretion, and metabolism) studies in rats and dogs was also conducted using a radioactive labeled tinengotinib, [14C]tinengotinib. Tinengotinib was found to have high permeability and high plasma protein binding and equally distributed between blood and plasma. There were no unique metabolites in human liver microsomes and tinengotinib showed moderate hepatic clearance. Tinengotinib is neither a potential inhibitor nor an inducer of P450 enzymes at clinically relevant concentrations, and unlikely to cause drug-drug interactions when used in combination with other drugs mediated by a key transporter, either as victim or perpetrator. Taken together, tinengotinib demonstrated a minimal risk of clinically relevant drug-drug interactions. Tinengotinib showed good oral bioavailability and dose-dependent exposures in both rat and dog after oral administration. The total radioactivity was largely distributed in the gastrointestinal system and liver, and tinengotinib could not easily pass through the blood-brain barrier. The major drug-related component in rat and dog plasma was unchanged drug (>89 %) with primary route of elimination via feces (>93 % of the dose) and minor via renal excretion (<4 % of the dose). Tinengotinib metabolism is mediated largely by CYP3A4, with minor contributions from CYP2D6 and CYP2C8. Major metabolic pathways include oxidation, oxidative cleavage of the morpholine ring, glucuronide and glutathione conjugations. The overall preclinical pharmacokinetics profile supported the selection and development of tinengotinib as a clinical candidate.

A Survey of Clinician Perspectives on the Management of Catheter-Related Upper Extremity Deep Vein Thrombosis in Patients with Cancer

Background: Central venous catheters (CVCs) are commonly used in cancer patients to facilitate blood draws, administration of chemotherapy or other supportive care treatment. Catheter-related upper extremity deep vein thrombosis (DVT) is a major complication of CVCs, with studies reporting a rate of symptomatic venous thromboembolism (VTE) of 7% over 3 months in patients with active cancer and a new CVC. Despite the frequent occurrence, the optimal management in patients with cancer and catheter-related upper extremity DVT is unclear, given the lack of high-quality data. Objective: We conducted a survey aiming to characterize practice patterns and perceptions of clinicians who treat patients with cancer and catheter-related upper extremity DVT. Methods: An online survey was distributed to international clinicians who manage patients with cancer and catheter-related upper extremity DVT. The survey explored the type and duration of anticoagulation, focusing on the management after the initial 3 months of anticoagulation, as well as treatment strategies upon catheter removal and interests in future clinical studies. Descriptive statistics was used to summarize survey responses. Results: The survey was generated on LimeSurvey ® in English and publicized by Twitter ® and email communications via multiple international organizations of hematologists, oncologists, and/or thrombosis specialists, including the International Society on Thrombosis and Haemostasis (ISTH), Thrombosis Canada, the Canadian Venous Thromboembolism Research Network (CanVECTOR), and more. As of July 30, 2023, 115 clinicians from 26 countries had completed the survey. The majority of the respondents specialized in thrombosis (N=72, 62.6%) and/or hematology (N=60, 52.2%), followed by internal medicine (N=38, 33.0%) and oncology (N=14, 12.2%) (multiple selection was permitted for this question). For the initial management of a patient without unresected gastrointestinal (GI) or genitourinary (GU) cancer, thrombocytopenia, or relevant drug-drug interactions, 75% of clinicians would prescribe a direct oral anticoagulant (DOAC) and 25% would give low-molecular-weight heparin (LMWH). On the other hand, in patients with unresected GI/GU cancer, the majority (N=105, 91.3%) of respondents chose to initiate LMWH. After the initial 3 months of anticoagulation, if the CVC remains in place in a patient with active cancer, the majority (N=112/114, 98.2%) of clinicians would continue anticoagulation, but with variable doses (57% and 43% chose therapeutic and prophylactic dosing, respectively). If the CVC remains in place but the cancer is in remission, fewer (70%) respondents would continue anticoagulation, and more would continue prophylactic as compared to therapeutic dosing (73% vs. 27%) in this setting. Practice variation further increases upon catheter removal, especially in the presence of active cancer (Figures 1 and 2). The majority of respondents (N=111, 96.5%) agree that there is a need for prospective studies to evaluate the management of patients with cancer and catheter-related upper extremity DVT, and over 91% (N=105) would consider enrolling their patients in a study to evaluate prophylactic dosing of anticoagulation for secondary prevention of VTE in patients with cancer and catheter-related upper extremity DVT. To help plan such a study, we evaluated respondents' perception on the maximal “tolerable” recurrent VTE rate between 3 and 6 months (as the main interest is in the management strategy after the initial 3 months), and 2% and 3% were the most common responses (41.2% and 31.6% of the respondents, respectively). Conclusions: Our survey demonstrates that current practice in managing patients with cancer and catheter-related upper extremity DVT is heterogenous, especially after the initial 3 months of anticoagulation and upon catheter removal. Well-conducted prospective studies in this population are needed, which is supported by most clinicians.

Detection and management of clinically relevant drug-drug interactions with direct oral anticoagulants in ambulatory care: a prospective interventional study in community pharmacies

Abstract Background/Introduction Direct oral anticoagulants (DOACs) are increasingly used but can be involved in clinically relevant drug-drug interactions (DDIs) that increase the risk of major bleeding or thromboembolism. Community pharmacists, who have access to patients’ complete medication profiles, including over-the-counter medication and medication from different prescribers, can play a crucial role in detecting and managing DDIs with DOAC in ambulatory care. Purpose This study aimed to detect and manage DDIs with DOAC in ambulatory care, because such real-life clinical practice studies are currently lacking. Methods A prospective interventional study was conducted between October 2021 and August 2022 in 201 community pharmacies in Belgium. On random days, every patient purchasing a DOAC or an interacting drug was screened for the presence of a DDI with DOAC. The pharmacist contacted the physician to discuss the management of the interaction. For the screening and management of DDI with DOAC, a previously developed practice-oriented DDI list for ambulatory care was used [1]. Results In total, 751 patients (74.5±10.7 years) were included, in whom 875 DDIs were identified. The three most commonly involved interacting drugs were (selective) serotonin (norepinephrine) reuptake inhibitors (32.9%), antiplatelets (30.9%), and non-steroidal anti-inflammatory drugs (28.9%). Most DDIs (83.1%) were not new (patients were already using these drugs) and 8.7% of interacting drugs were dispensed over-the-counter. In almost one-third of DDIs (28.0%), the interacting drug and the DOAC were prescribed by different physicians. Prescribers rated the clinical risks of the identified DDIs as high (15.9%), moderate (33.1%), and low (38.7%), whereas 12.3% were unaware of the potential risks. Remarkably, in 18 patients who were concomitantly taking an antiplatelet and DOAC, the prescriber reported forgetting to stop the antiplatelet or not being aware that the patient was taking both medications. Three patients were also found to be using another anticoagulant along with DOAC due to miscommunication between prescribers. When discussing how to manage the DDI, pharmacotherapy was mostly unchanged (60.2%). Physicians cited reasons such as the interacting drug being deemed necessary (37.2%), the patient already using a proton pump inhibitor (PPI) (19.5%), or the patient using both interacting drugs already for a long time without problems (18.6%). However, in 39.8% of cases, the discussion resulted in a pharmacotherapy change. The most common changes included stopping the interacting drug (21.5%), initiating a PPI (17.6%), or replacing the interacting drug with a safer alternative (14.5%). Conclusion This study illustrated that community pharmacists, in collaboration with physicians, can contribute to reducing avoidable patient harm from DDIs with DOACs.

Observational study of drug-drug interactions in oncological inpatients

ObjectiveTo determine the prevalence of potential clinically relevant drug-drug interactions in adult oncological inpatients, as well as to describe the most frequent interactions. A standard database was used. MethodAn observational, transversal, and descriptive study including patients admitted to the Oncology Service of a reference hospital. All prescriptions were collected twice a week during a month. They were analysed using Lexicomp® database, recording all interactions classified with a level of risk: C, D or X. ResultsA total of 1 850 drug-drug interactions were detected in 218 treatments. The prevalence of treatments with at least one clinically relevant interaction was 95%, being 94.5% for those at level C and 26.1% for levels D and X. The drugs most commonly involved in the interactions detected were opioid analgesics, antipsychotics (butyrophenones), benzodiazepines, pyrazolones, glucocorticoids and heparins, whereas interactions with antineoplastics were minimal, highlighting those related to paclitaxel and between metamizole and various antineoplastics. ConclusionsThe prevalence of clinically relevant drug-drug interactions rate was very high, highlighting the high risk percentage of them related to level of risk X. Due to the frequency of onset and potential severity, highlighted the concomitant use of central nervous system depressants drugs with risk of respiratory depression, the risk of onset of anticholinergic symptoms when combining morphine or haloperidol with butylscopolamine, ipratropium bromide or dexchlorpheniramine and the multiple interactions involving metamizole.

Olaparib plus Abiraterone for Metastatic Castration-resistant Prostate Cancer: Pharmacokinetics Data from the PROpel Trial

PROpel (NCT03732820) was a positive phase 3 trial that demonstrated a clinically significant improvement in radiographic progression-free survival with olaparib plus abiraterone versus placebo plus abiraterone in first-line metastatic castration-resistant prostate cancer. For a subset of PROpel patients, steady-state concentrations of olaparib, abiraterone, and Δ4-abiraterone were measured in blood samples collected before and at several time points after dose administration. The pharmacokinetics (PK) for each drug and metabolite were evaluated to determine whether any clinically relevant drug-drug interactions between olaparib and abiraterone occurred. The results demonstrate that steady-state PK parameters for olaparib and abiraterone in PROpel were comparable with those in monotherapy trials. Abiraterone steady-state exposures were similar between treatment arms. Δ4-Abiraterone had slightly lower steady-state exposures when abiraterone was administered in combination with olaparib. These results are consistent with a previous phase 2 study, supporting the conclusion that no clinically relevant PK-based drug-drug interactions occurred when olaparib and abiraterone were given in combination at their full monotherapy doses. Patient summaryWhen drugs are administered in combination, a key consideration is whether there are any interactions between the drugs that may affect their activity. We analyzed blood concentrations of olaparib and abiraterone in a subset of patients with prostate cancer from the PROpel trial to determine if there were interactions between these two drugs. We found that there was no significant effect on the profile of either drug when they were given together at the same doses used when each drug is given individually.

Prevalence and types of drug interactions in hospitalized pediatric patients in Mexico City

ObjectiveDrug-drug interactions may modify the therapeutic effect or the safety profile of the medicines used in pediatric populations. Although interest on potential drug interactions in these age groups has increased, information on clinically relevant drug-drug interactions is still scarce. The aim of this study was to explore the prevalence and characteristics of potential and clinically relevant drug-drug interactions among pediatric patients hospitalized in two pediatric hospitals of Mexico City. MethodA cross-sectional study was conducted on patient records in critical, oncological, burns and other non-critical services by a pediatric resident physician at both hospitals. Micromedex® was used as a source of potential drug-drug interactions data. Subsequently, each interaction's prevalence, severity and evidence level were estimated. Additionally, drug-drug interaction causality with regard to diverse clinical outcomes of hospitalized patients was determined through the Drug Interaction Probability Scale. The clinical consequences of each interaction were classified by severity. ResultsThe observed prevalence of one or more potential drug-drug interactions in hospitalized patients was 61.3% (52.2-70.4%), whilst the prevalence of real drug-drug interactions was 3.6% (0.1-7.1%). Of potential drug-drug interactions, 60.5% were considered major and only 5.1% contraindicated. These were generally more common in intensive care and burn units. The main pharmacological agents involved in potential drug-drug interactions were opioids analgesics and anti-infective and neurologic agents. Four clinically relevant drug-drug interactions required a regimen change and another prompted an extension of the patient's hospital stay. ConclusionsPotential drug-drug interactions were common in the pediatric patients studied, whereas the frequency of real drug-drug interactions was low. However, some drug-drug interactions required medical actions in addition to routine monitoring. More information is needed on real drug-drug interactions as those related to failed efficacy might be underestimated.

Drug-Drug Interactions between Tamsulosin and Mirabegron in Healthy Individuals Do Not Affect Pharmacokinetics and Hemodynamic Parameters Significantly.

Overactive bladder (OAB) is characterized by urinary urgency and increased urinary frequency, substantially affecting quality of life. Tamsulosin and mirabegron combination therapy has been studied as a safe and effective treatment option for patients with OAB. This study evaluated the effects of combining these two drugs on their pharmacokinetics and safety profiles in healthy Korean males. In this open-label, fixed-sequence, three-period, drug-drug interaction phase 1 study, a total of 36 male participants were administered multiple doses of tamsulosin alone (0.2 mg once daily), mirabegron alone (50 mg once daily), or a combination of both drugs. The results showed that the combination of tamsulosin and mirabegron increased tamsulosin exposure in the plasma by approximately 40%. In contrast, the maximum plasma concentration of mirabegron was reduced by approximately 17% when administered with tamsulosin. No clinically significant changes in the safety profiles, vital signs, or clinical laboratory test results were observed in this study. In conclusion, there were no clinically relevant drug-drug interactions between tamsulosin and mirabegron in terms of pharmacokinetics, safety, and tolerability, suggesting that their combination could be a promising treatment option for patients with OAB.

Applied physiologically-based pharmacokinetic modeling to assess uridine diphosphate-glucuronosyltransferase-mediated drug-drug interactions for Vericiguat.

Vericiguat (Verquvo; US: Merck, other countries: Bayer) is a novel drug for the treatment of chronic heart failure. Preclinical studies have demonstrated that the primary route of metabolism for vericiguat is glucuronidation, mainly catalyzed by uridine diphosphate-glucuronosyltransferase (UGT)1A9 and to a lesser extent UGT1A1. Whereas a drug-drug interaction (DDI) study of the UGT1A9 inhibitor mefenamic acid showed a 20% exposure increase, the effect of UGT1A1 inhibitors has not been assessed clinically. This modeling study describes a physiologically-based pharmacokinetic (PBPK) approach to complement the clinical DDI liability assessment and support prescription labeling. A PBPK model of vericiguat was developed based on invitro and clinical data, verified against data from the mefenamic acid DDI study, and applied to assess the UGT1A1 DDI liability by running an in silico DDI study with the UGT1A1 inhibitor atazanavir. A minor effect with an area under the plasma concentration-time curve (AUC) ratio of 1.12 and a peak plasma concentration ratio of 1.04 was predicted, which indicates that there is no clinically relevant DDI interaction anticipated. Additionally, the effect of potential genetic polymorphisms of UGT1A1 and UGT1A9 was evaluated, which showed that an average modest increase of up to 1.7-fold in AUC may be expected in the case of concomitantly reduced UGT1A1 and UGT1A9 activity for subpopulations expressing non-wild-type variants for both isoforms. This study is a first cornerstone to qualify the PK-Sim platform for use of UGT-mediated DDI predictions, including PBPK models of perpetrators, such as mefenamic acid and atazanavir, and sensitive UGT substrates, such as dapagliflozin and raltegravir.

The prevalence of relevant drug-drug interactions and associated clinical outcomes in patients with cancer-associated thrombosis on concurrent anticoagulation and anticancer or supportive care therapies

BackgroundA main concern in the management of patients with cancer-associated thrombosis (CAT) is drug-drug interactions (DDIs) between anticoagulants and anticancer therapies. Their clinical implications remain unclear. MethodsTo quantify the prevalence of DDIs and risks of recurrent venous thromboembolism (VTE) and bleeding events in patients with CAT on anticoagulation, we conducted a retrospective cohort study in patients with CAT on concurrent anticoagulants and anticancer and/or supportive care therapies. All patients were followed for 6 months from CAT diagnosis or until death (whichever occurred first). The primary outcome was the percentage of patients with anticoagulant DDIs classified as risk C, D, or X in Lexicomp® at any time during the 6 months. Secondary outcomes included recurrent VTE and clinically relevant bleeding events. We calculated the 6-month cumulative incidence of outcomes with 95 % confidence interval (CI) and compared those with and without DDIs, considering death as a competing risk. ResultsAmong 267 patients included, 111 (41.6 %) had DDIs with anticoagulants at any time during the study. Those on DOACs at any time had more DDIs compared to LMWH (50.9 % vs 19.3 %, p < 0.0001). The 6-month incidence was 8.2 % (95 % CI 5.3–11.9) for recurrent VTE and 6.7 % (95 % CI 4.2–10.2) for clinically relevant bleeding, with no significant differences between groups with or without DDIs. ConclusionsThere are high incidences of DDIs in patients with CAT on anticoagulants, more with DOACs. DDIs classified as risk C, D, or X by Lexicomp® were not associated with recurrent VTE or bleeding events in our cohort.

OC 71.3 The Prevalence of Relevant Drug-Drug Interactions and Associated Clinical Outcomes in Patients with Cancer-Associated Thrombosis on Concurrent Anticoagulation and Anticancer Therapies

OC 71.3 The Prevalence of Relevant Drug-Drug Interactions and Associated Clinical Outcomes in Patients with Cancer-Associated Thrombosis on Concurrent Anticoagulation and Anticancer Therapies

Oestradiol concentrations in trans women with HIV suppressed on unboosted integrase inhibitor regimens versus trans women without HIV taking oral oestradiol: a pilot study.

Feminizing hormone therapy (FHT) is essential to many trans women. Concern about negative drug interactions between FHT and ART can be an ART adherence barrier among trans women with HIV. In this single-centre, parallel group, cross-sectional pilot study, we measured serum oestradiol concentrations in trans women with HIV taking FHT and unboosted integrase strand transfer inhibitor (INSTI)-based ART versus trans women without HIV taking FHT. We included trans women with and without HIV, aged ≥18 years, taking ≥2 mg/day of oral oestradiol for at least 3 months plus an anti-androgen. Trans women with HIV were on suppressive ART ≥3 months. Serum oestradiol concentrations were measured prior to medication dosing and 2, 4, 6 and 8 h post-dose. Median oestradiol concentrations were compared between groups using Wilcoxon rank-sum tests. Participants (n = 8 with HIV, n = 7 without) had a median age of 32 (IQR: 28, 39) years. Among participants, the median oral oestradiol dose was 4 mg (range 2-6 mg). Participants had been taking FHT for a median of 4 years (IQR: 2, 8). Six trans women with HIV were taking bictegravir/emtricitabine/tenofovir alafenamide and two were taking dolutegravir/abacavir/lamivudine. All oestradiol concentrations were not significantly different between groups. Eleven (73%) participants had target oestradiol concentrations in the range 200-735 pmol/L at C4h (75% among women with HIV, 71% among those without HIV). Oestradiol concentrations were not statistically different in trans women with HIV compared with those without HIV, suggesting a low probability of clinically relevant drug-drug interactions between FHT and unboosted INSTI-based ART.