Potential drug-drug and drug-disease interactions in prescriptions for ambulatory patients over 50 years of age in family medicine clinics in Mexico City

Prevalence and differences in the co-administration of drugs known to interact: an analysis of three distinct and large populations

BACKGROUND

The co-administration of drugs known to interact greatly impacts morbidity, mortality, and health economics. This study aims to examine the drug-drug interaction (DDI) phenomenon with a large-scale longitudinal analysis of age and gender differences found in drug administration data from three distinct healthcare systems.

METHODS

This study analyzes drug administrations from population-wide electronic health records in Blumenau (Brazil; 133 K individuals), Catalonia (Spain; 5.5 M individuals), and Indianapolis (USA; 264 K individuals). The stratified prevalences of DDI for multiple severity levels per patient gender and age at the time of administration are computed, and null models are used to estimate the expected impact of polypharmacy on DDI prevalence. Finally, to study actionable strategies to reduce DDI prevalence, alternative polypharmacy regimens using drugs with fewer known interactions are simulated.

RESULTS

A large prevalence of co-administration of drugs known to interact is found in all populations, affecting 12.51%, 12.12%, and 10.06% of individuals in Blumenau, Indianapolis, and Catalonia, respectively. Despite very different healthcare systems and drug availability, the increasing prevalence of DDI as patients age is very similar across all three populations and is not explained solely by higher co-administration rates in the elderly. In general, the prevalence of DDI is significantly higher in women - with the exception of men over 50 years old in Indianapolis. Finally, we show that using proton pump inhibitor alternatives to omeprazole (the drug involved in more co-administrations in Catalonia and Blumenau), the proportion of patients that are administered known DDI can be reduced by up to 21% in both Blumenau and Catalonia and 2% in Indianapolis.

CONCLUSIONS

DDI administration has a high incidence in society, regardless of geographic, population, and healthcare management differences. Although DDI prevalence increases with age, our analysis points to a complex phenomenon that is much more prevalent than expected, suggesting comorbidities as key drivers of the increase. Furthermore, the gender differences observed in most age groups across populations are concerning in regard to gender equity in healthcare. Finally, our study exemplifies how electronic health records' analysis can lead to actionable interventions that significantly reduce the administration of known DDI and its associated human and economic costs.

The Prevalence and Severity of Potential Drug-Drug Interactions in Internal Medicine Ward at Soba Teaching Hospital

Background

Multiple drug therapies are commonly used to achieve a desired therapeutic goal, especially in hospitalized patients. However, drug-drug interactions might occur and threaten the patients' safety.

Objective

This study aims to assess the prevalence and severity of potential drug-drug interactions (PDDIs) in the internal medicine ward at Soba Teaching Hospital.

Methods

A retrospective cross-sectional hospital-based study was carried out in the internal medicine ward at Soba Teaching Hospital from June 2021 to December 2021. The data was collected from patients' medical records. PDDIs were identified using Lexicomp® drug interaction software.

Results

A total of 377 patients were included in this study, and overall prevalence of PDDIs was 62.9%. We have identified 989 potential DDIs and 345 pairs of interacting drugs, the mean of the PDDIs per patient was 4.17 ± 4.079. Among 345 PDDIs most were of moderate interactions 70.1% (n=242) followed by Minor interactions 19.1% (n=66). The most common type of interaction was of category C representing 63.5% (n=219). A significant association was observed between the occurrence of PDDIs with patients' age, presence of chronic diseases, length of hospital stay, and number of medications received by the patients.

Conclusion

Drug-drug interactions were highly prevalent in the internal medicine ward. Therefore, certain attempts are required to increase the awareness of the physicians about these interactions and minimize their occurrence.

Ambulatory Medication Safety in Primary Care: A Systematic Review

PURPOSE

To review the literature on medication safety in primary care in the electronic health record era.

METHODS

Included studies measured rates and outcomes of medication safety in patients whose prescriptions were written in primary care clinics with electronic prescribing. Four investigators independently reviewed titles and analyzed abstracts with dual-reviewer review for eligibility, characteristics, and risk of bias.

RESULTS

Of 1464 articles identified, 56 met the inclusion criteria. Forty-three studies were noninterventional and 13 included an intervention. The majority of the studies (30) used their own definition of error. The most common outcomes were potentially inappropriate prescribing/medications (PIPs), adverse drug events (ADEs), and potential prescribing omissions (PPOs). Most of the studies only included high-risk subpopulations (39), usually older adults taking > 4 medications. The rate of PIPs varied widely (0.19% to 98.2%). The rate of ADEs was lower (0.47% to 14.7%). There was poor correlation of PIP and PPO with documented ADEs leading to physical harm.

CONCLUSIONS

This literature is limited by its inconsistent and highly variable outcomes. The majority of medication safety studies in primary care were in high-risk populations and measured potential harms rather than actual harms. Applying algorithms to primary care medication lists significantly overestimates rate of actual harms.

Advanced Medication Alert System Decreased Hospital-Based Outpatient Duplicated Medications: A Longitudinal Hospital Cohort Study

OBJECTIVES

This study aimed to examine the associations between adoption of an advanced medication alert system and decreases in hospital-based outpatient duplicated medication rates in Taiwan.

METHODS

The unit of analysis was the hospital. We merged the hospital medication alert system adoption survey data and Taiwan National Health Insurance outpatient claims data. The observation time was 1998 to 2011, divided into 5 periods (T1-T5). The analysis included 216 hospitals, and outcome variable was hospital-based outpatient duplicated medication rates. The system adoption time frame, hospital accreditation level, and number of drugs per prescription were defined as predicted variables. A generalized estimating equation regression model was used.

RESULTS

Adoption of the advanced medication alert system gradually increased, such that 100% of medical centers and 84% of regional hospitals, but less than 50% of district hospitals, had systems by T5. The hospital-based outpatient duplicated medication rate continually decreased, from 29.8% to 11.2%. The generalized estimating equation model showed rates of duplicated medications of b = -8.44 at T2 and b = -17.88 at T5 (P < 0.001) compared with T1. Medical centers and regional hospitals demonstrated much lower duplication rates (b = -13.71, b = -6.82; P < 0.001) compared with district hospitals. Hospitals with more medications per prescription had higher duplication rates than did hospitals with fewer items.

CONCLUSIONS

Hospitals accredited at higher levels tended to have advanced medication alert systems. Hospitals that implemented advanced systems decreased hospital-based outpatient duplicated medications, avoiding a potential risk due to inappropriate medication use.

The Prevalence of Potential Drug-Drug Interactions in CKD-A Retrospective Observational Study of Cerrahpasa Nephrology Unit

Background and Objectives: Chronic kidney disease (CKD) is usually linked with polypharmacy and patients are invariably at risk of complex medication regimens. The present study was designed to estimate the potential drug-drug interactions (pDDIs) through the prescription patterns provided to patients of the Nephrology Transplant Unit of Cerrahpasa Medical Faculty patients. Materials and Methods: 96 patients were included in the study. pDDIs among every combination of the prescribed drug were analyzed using the Thomson Reuters Micromedex. Results: We found 149 pDDIs making 2.16 interactions per prescription with incidence rates of 69.7%. Approximately 4.1% of interactions were of significant severity, 75.1% moderate severity, and 20.8% were classified as minor pDDIs. The most frequent interactions were found between iron and aluminum, calcium or magnesium-containing products (21.37%), calcium channel blockers and beta-blockers (8.96%); and aspirin and aluminum, calcium, or magnesium-containing products (7.58%). We identified 42 drug pairs with probability of clinical significance. The most commonly reported clinical outcomes of the pDDIs were hypo- or hypertension (39.24%), decreased drug efficacy (24.05%), and arrhythmia (9.49%). Aluminum, calcium, or magnesium-containing drug products (33.10%) constituted the primary class of drugs involved in interactions. Conclusions: This study showed pharmacodynamics (49%), pharmacokinetics (42.94%) interactions, polypharmacy and gender as determinant of pDDIs. A comprehensive multicenter research is required to decrease the morbidity and ease the state burden.

Risk Factors for the Occurrence of Potential Drug-Drug Interactions in Surgical Patients

Background: Drug-drug interactions are defined as modifications of the drug action that result from the simultaneous administration of another individual drug or several drugs. Nowadays, potential drug-drug interactions (DDIs) are most frequently detected and analyzed using personal digital assistant software programs (online interaction checker tools).

Objective: To determine the risk factors for the emergence of all drug-drug interactions in surgical patients with particular emphasis on clinically significant interactions.

Patients and methods: This was a retrospective cohort analysis of patients treated at the Surgical Clinic of the Clinical Center Kragujevac. Three interaction checkers were used to reveal drug-drug interactions: Medscape, Epocrates and Micromedex.

Results: The study included total of 200 patients, aged 58.54±17.08 years. Average number of drug-drug interactions per patient was between 10.50±9.10 (Micromedex) and 18.75±17.14 (Epocrates). Number of prescribed drugs, antidepressive therapy, antiarrhythmic therapy, number of pharmacological/therapeutic subgroups (2nd level of ATC classification) prescribed, delirium or dementia, diabetes, heart failure, and number of physicians who prescribed drugs to single patient were identified as risk factors for drug-drug interactions while length of hospitalization in days and age of patient in years emerged as protective factors.

Conclusion: Drug-drug interactions are relatively common in surgical patients and predisposed by factors such as number of prescribed drugs or drug group per patient, number of physicians who prescribed drugs, antidepressive therapy, antiarrhythmic therapy, presence of delirium or dementia, diabetes and heart failure. On the other hand, prolonged hospitalization and higher age are factors that reduce the risk of interactions in surgical patients.

Determination of potential drug-drug interactions in prescription orders dispensed in a community pharmacy setting using Micromedex® and Lexicomp®: a retrospective observational study

Background Community pharmacists have a role in identifying drug-drug interactions (DDIs) when processing prescription orders and dispensing medications to patients. The harmful effects of DDIs can be prevented or minimized by using an electronic DDI checker to screen for potential DDIs (pDDIs). However, different DDI checkers have variable rates of detecting pDDIs. Aim To estimate the prevalence of pDDIs in prescriptions dispensed in a community pharmacy setting using two electronic DDI databases and to evaluate the association between the pDDIs and contributory factors. Method Eligible prescription orders dispensed by a community pharmacy chain in Qatar from January to July 2020 were included in this retrospective observational study. For each prescription, Micromedex^® and Lexicomp^® were simultaneously used to identify pDDIs, and the interactions categorized based on severity and risk rating. Results Seven hundred-twenty prescriptions met the inclusion criteria, of which Micromedex^® and Lexicomp^® respectively identified 125 prescriptions (17.4%) and 230 prescriptions (31.9%) as having at least one pDDI. Moderate strength of agreement was found between Lexicomp^® and Micromedex^® in identifying pDDIs (Cohen's Kappa = 0.546). Micromedex^® classified 61.6% of DDIs as major severity, while Lexicomp^® classified 30.8% as major severity. The number of concurrent medications per prescription was significantly and positively associated with pDDI. Conclusion This study demonstrates a high prevalence of pDDIs among prescriptions dispensed in a community pharmacy setting. It is advisable that community pharmacists in Qatar, who typically do not have access to computerized patient profiles, use these DDI checkers to ensure all pDDIs are communicated to respective prescribers for appropriate action.

Prevalence of drug-drug interactions in older people before and after hospital admission: analysis from the OPERAM trial

Background

Drug-drug interactions (DDIs) are highly prevalent in older patients but little is known about prevalence of DDIs over time. Our main objective was to assess changes in the prevalence and characteristics of drug-drug interactions (DDIs) during a one-year period after hospital admission in older people, and associated risk factors.

Methods

We conducted a sub-study of the European OPERAM trial (OPtimising thERapy to prevent Avoidable hospital admissions in Multimorbid older people), which assessed the effects of a structured medication review (experimental arm) compared to usual care (control arm) on reducing drug-related hospital readmissions. All OPERAM patients (≥70 years, with multimorbidity and polypharmacy, hospitalized in four centers in Bern, Brussels, Cork and Utrecht between December 2016 and October 2018, followed over 1 year) who were alive at hospital discharge and had full medication data during the index hospitalization (at baseline i.e., enrolment at admission, and at discharge) were included. DDIs were assessed using an international consensus list of potentially clinically significant DDIs in older people. The point-prevalence of DDIs was evaluated at baseline, discharge, and at 2, 6 and 12 months after hospitalization. Logistic regression models were performed to assess independent variables associated with changes in DDIs 2 months after baseline.

Results

Of the 1950 patients (median age 79 years) included, 1045 (54%) had at least one potentially clinically significant DDI at baseline; point-prevalence rates were 58, 57, 56 and 57% at discharge, and 2, 6 and 12 months, respectively. The prevalence increased significantly from baseline to discharge (P < .001 [significant only in the control group]), then remained stable over time (P for trend .31). The five most common DDIs –all pharmacodynamic in nature– accounted for 80% of all DDIs and involved drugs that affect potassium concentrations, centrally-acting drugs and antithrombotics. At 2 months, DDIs had increased in 459 (27%) patients and decreased in 331 (19%). The main factor predictive of a change in the prevalence of DDIs was hyperpolypharmacy (≥10 medications).

Conclusions

DDIs were very common; their prevalence increased during hospitalization and tended to remain stable thereafter. Medication review may help control this increase and minimize the risk of adverse drug events.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02532-z.

Representing a Heterogeneous Pharmaceutical Knowledge-Graph with Textual Information

We deal with a heterogeneous pharmaceutical knowledge-graph containing textual information built from several databases. The knowledge graph is a heterogeneous graph that includes a wide variety of concepts and attributes, some of which are provided in the form of textual pieces of information which have not been targeted in the conventional graph completion tasks. To investigate the utility of textual information for knowledge graph completion, we generate embeddings from textual descriptions given to heterogeneous items, such as drugs and proteins, while learning knowledge graph embeddings. We evaluate the obtained graph embeddings on the link prediction task for knowledge graph completion, which can be used for drug discovery and repurposing. We also compare the results with existing methods and discuss the utility of the textual information.

Drug interactions detected by a computer-assisted prescription system in primary care patients in Spain: MULTIPAP study

Background

Drug interactions increase the risk of treatment failure, intoxication, hospital admissions, consultations and mortality. Computer-assisted prescription systems can help to detect interactions.

Objectives

To describe the drug–drug interaction (DDI) and drug–disease interaction (DdI) prevalence identified by a computer-assisted prescription system in patients with multimorbidity and polypharmacy. Factors associated with clinically relevant interactions were analysed.

Methods

Observational, descriptive, cross-sectional study in primary health care centres was undertaken in Spain. The sample included 593 patients aged 65–74 years with multimorbidity and polypharmacy participating in the MULTIPAP Study, recruited from November 2016 to January 2017. Drug interactions were identified by a computer-assisted prescription system. Descriptive, bivariate, and multivariate analyses with logistic regression models and robust estimators were performed.

Results

Half (50.1% (95% CI 46.1–54.1)) of the patients had at least one relevant DDI and 23.9% (95% CI 18.9–25.6) presented with a DdI. Non-opioid–central nervous system depressant drug combinations and benzodiazepine–opioid drug combinations were the two most common clinically relevant interactions (10.8% and 5.9%, respectively). Factors associated with DDI were the use of more than 10 drugs (OR 11.86; 95% CI 6.92–20.33) and having anxiety/depressive disorder (OR 1.98; 95% CI 1.31–2.98). Protective factors against DDI were hypertension (OR 0.62; 95% CI 0.41–0.94), diabetes (OR 0.57; 95% CI 0.40–0.82), and ischaemic heart disease (OR 0.43; 95% CI 0.25–0.74).

Conclusion

Drug interactions are prevalent in patients aged 65–74 years with multimorbidity and polypharmacy. The clinically relevant DDI frequency is low. The number of prescriptions taken is the most relevant factor associated with presenting a clinically relevant DDI.

Assessment of Potential Drug–Drug Interactions and Their Predictors in Chronic Outpatient Department of Dessie Referral Hospital, Dessie, Northeast Ethiopia

Objective

To assess the prevalence and predictors of Potential drug–drug interactions (DDIs) at the chronic outpatient department of Dessie Referral Hospital, Dessie, Northeast Ethiopia.

Patients and Methods

A cross-sectional study was carried out on the medical records of patients treated in the chronic ambulatory department of Dessie Referral Hospital (DRH), from March 1/2019 to May 30/2019. Ethical clearance was granted from the department of pharmacy, college of medicine, and health sciences, Wollo University. Lexi-comp computer program database was used to detect pDDIs. SPSS version 22 was used to produce a descriptive analysis of the background data and logistic regression to identify predictors of pDDIs.

Results

In this study, the medical record of 300 patients has been reviewed and 489 pDDIs have been identified. The prevalence of pDDIs per patient was 1.63. Of all the identified pDDIs, the moderate severity interactions were the majority, 88.55% (n=433) followed by 8.38% (n=41) of minor, 2.66% (n=13) of major, and 0.41% (n=2) of contraindicated drug interactions. Taking three or more drugs at a time has been found as a statistically significant predictor of the occurrence of pDDIs.

Conclusion

A high rate of moderate severity pDDIs have been recorded. A system of checks and balances should be developed and executed for all those who are involved in prescribing, dispensing, and administration of medications for effective identification and prevention of pDDIs.

Assessing Drug-Drug Interaction Potential among Patients Admitted to Surgery Departments in Three Palestinian Hospitals

Background

Drug-drug interactions (DDIs) are a common issue that leads to adverse drug reactions in hospitals. Patients in the surgical department are expected to have potential DDIs that may lead to morbidity and mortality.

Objectives

To study potential DDI prevalence in the surgery departments in 3 hospitals in Palestine. Moreover, to identify pertinent factors that are associated with drug-drug interactions.

Method

A cross-sectional study in 3 governmental Palestinian hospitals: Palestine Medical Complex, Rafidia Hospital, and Beit Jala Hospital. Patients who are 20 years old or above and admitted to the surgical wards between September 2017 and February 2018 were included in the study. Patient demographics, all medications given in the hospital, and hospitalization period were obtained from medical files. The digital clinical decision support system Micromedex® was used for analysis and classification of possible drug interactions. Bivariate analysis and logistic regression were used to study the risk factors for developing DDIs.

Results

502 patients were included in this report. The prevalence of potential DDIs among patients admitted to surgery wards in three Palestinian hospitals was 56%. The number of detected potential DDIs per patient was 2.22 ± 3.76. The number of prescribed medications (P < 0.001) was found to increase the possibility of having drug interactions.

Conclusions

DDIs in Palestinian hospitals are a prevalent problem, and caution should be taken when ordering medications to hospitalized patients in surgery departments.

A Prospective Analysis of Potential and Observed Drug-Drug Interactions, Adverse Events and its Associated Risk Factors in Hospitalized Cardiology Patients in Benin

BACKGROUND & AIMS

The objective is to ascertain the pattern of potential drug-drug interactions (pDDIs) and record any observed DDIs and adverse events (AEs) in hospitalized Beninese cardiology patients from Sub-Saharan Africa and analyze all risk factors associated with DDIs and AEs.

METHODS

It was a prospective study in which data including AEs were assessed from medical files and interview of patients and their relatives. Patients who were treated with more than two drugs and who remained in the hospital for at least 48 hours were included. A computerized database system Pharma IAM- VIDAL version 2011 was used to identify the pattern for potential DDIs.

RESULTS

156 patients were included in this study. The prevalence of potential DDIs was estimated at 93 % (145/156). Forty (5.1%) among 804 potential DDIs identified were observed clinically. The observed DDIs were attributable to low blood pressure (27.5%), hyponatremia (22.5%), hemorrhage (20.0%), hyperkalemia (17.5%) and nephrotoxicity (7.5%). The combination of spironolactone and furosemide resulted in hyponatremia while the combination of enoxaparin and potassium resulted in hyperkalemia. ACE inhibitor (or ARAII) in combination with furosemide resulted in the nephrotoxicity cases observed. Enoxaparin, Acetyl salicylic acid, Acenocoumarol and Clopidogrel were decreasingly involved in the pairs of drugs responsible for observed hemorrhages. 29 patients out of 156 (18.6%) had at least one AE. AEs were mainly (34.2%) of metabolic type. Severe AEs, which represented 18.4% was mostly from nephrotoxicity and metabolic disorders. More than 14 active substances multiplied the risk factor for AEs occurrence by 42, while more than 14 days hospitalization increased this risk by 42.

CONCLUSION

This study highlights the need to optimize treatments by strictly regulating blood pressure, serum sodium and potassium levels, coagulation parameters and looking for clinical signs of hemorrhage. Physician should be aware of certain drug associations that may carry a risk of severe adverse events.

Challenges facing drug utilization research in the Latin American region

PURPOSE

The International Society of Pharmacoepidemiology (ISPE) in collaboration with the Latin America Drug Utilization Research Group (LatAm DURG), the Medicines Utilization Research in Africa (MURIA) group, and the Uppsala Monitoring Center, is leading an initiative to understand challenges to drug utilization research (DUR) in the Latin American (LatAm) and African regions with the goal of communicating results and proposing solutions to these challenges in four scientific publications. The purpose of this first manuscript is to identify the main challenges associated with DUR in the LatAm region.

METHODS

Drug utilization (DU) researchers in the LatAm region voluntarily participated in multiple discussions, contributed with local data and reviewed successive drafts and the final manuscript. Additionally, we carried out a literature review to identify the most relevant publications related to DU studies from the LatAm region.

RESULTS

Multiple challenges were identified in the LatAm region for DUR including socioeconomic inequality, access to medical care, complexity of the healthcare system, limited investment in research and development, limited institutional and organization resources, language barriers, limited health education and literacy. Further, there is limited use of local DUR data by decision makers particularly in the identification of emerging health needs coming from social and demographic transitions.

CONCLUSIONS

The LatAm region faces challenges to DUR which are inherent in the healthcare and political systems, and potential solutions should target changes to the system.

Prevalence and significance of potential drug-drug interactions among cancer patients receiving chemotherapy

Background

Cancer patients often receive multiple drugs to maximize their therapeutic benefit, treat co-morbidities and counter the adverse effects of chemotherapy. Concomitant administration of multiple drugs increases the risk of drug interactions leading to compromised therapeutic efficacy or safety of therapy. The purpose of this study was to identify the prevalence, levels and predictors of potential drug-drug interactions (pDDIs) among cancer patients.

Methods

Six hundred and 78 patients receiving chemotherapy from two tertiary care hospitals were included in this cross-sectional study. Patient medication profiles were screened for pDDIs using the Micromedex® database. Logistic regression analysis was performed to identify the predictors of pDDIs.

Results

The overall prevalence of pDDIs was 78%, majority of patients had 1–2 pDDIs (39.2%). A total of 1843 pDDIs were detected. Major-pDDIs were most frequent (67.3%) whereas, a significant association of pDDIs was found between > 7 all prescribed drugs (p < 0.001) and ≥ 3 anti-cancer drugs (p < 0.001). Potential adverse outcomes of these interactions include reduced therapeutic effectiveness, QT interval prolongation, tendon rupture, bone marrow suppression and neurotoxicity.

Conclusions

Major finding of this study is the high prevalence of pDDIs signifying the need of strict patient monitoring for pDDIs among cancer patients. Patients at higher risk to pDDIs include those prescribed with > 7 any types of drugs or ≥ 3 anticancer drugs. Moreover, list of most frequently identified major and moderate interactions will aid health care professional in timely identification and prevention of pDDIs.

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.

Survey on Polypharmacy and Drug-Drug Interactions Among Elderly People with Cardiovascular Diseases at Yekatit 12 Hospital, Addis Ababa, Ethiopia

Background

Elderly people are most commonly associated with cardiac disease. Cardiovascular diseases are interlinked with co-morbidities which require multiple drug therapy in addition to cardiovascular drugs. This results to polypharmacy which carries a high risk of potential drug-drug interactions. Elderly patients are at a particular risk of drug related problems because of increased level of polypharmacy and the physiological changes which accompany aging. This study was aimed to assess polypharmacy and potential drug-drug interactions (DDIs) among elderly people with cardiovascular diseases at Yekatit 12 hospital.

Methodology

A retrospective cross-sectional study using patients chart review was conducted on all elderly people with cardiovascular diseases at Yekatit 12 hospital in the period between March 2018 and March 2019. The types, seriousness and level of potential DDIs were checked using Medscape online drug interaction checker.

Results

The mean number of drugs per prescription was 4.25 ± 1.754 and the prevalence of polypharmacy (concurrent use of 5 and more drugs) was 42.7%. Polypharmacy and potential DDIs were significantly associated with polymorbidity (P = 0.000), being hospitalized (P = 0.047) and congestive heart failure (P = 0.016). A total of 850-potential DDIs were identified, the mean number of potential DDIs was 3.37 per prescription. The potential DDIs were mainly significant (73.29%) in nature and pharmacodynamics (73.06%) in mechanism. The prevalence of total and serious potential DDIs were 84.3% and 17.3%, respectively. Most commonly interacting drug combination was aspirin + enalapril (30.2%).

Conclusion

A higher incidence of polypharmacy and increased risk of potential DDIs in elderly people with cardiovascular disease are major therapeutic issues at Yekatit 12 hospital.

Evaluation of knowledge graph embedding approaches for drug-drug interaction prediction in realistic settings

BACKGROUND

Current approaches to identifying drug-drug interactions (DDIs), include safety studies during drug development and post-marketing surveillance after approval, offer important opportunities to identify potential safety issues, but are unable to provide complete set of all possible DDIs. Thus, the drug discovery researchers and healthcare professionals might not be fully aware of potentially dangerous DDIs. Predicting potential drug-drug interaction helps reduce unanticipated drug interactions and drug development costs and optimizes the drug design process. Methods for prediction of DDIs have the tendency to report high accuracy but still have little impact on translational research due to systematic biases induced by networked/paired data. In this work, we aimed to present realistic evaluation settings to predict DDIs using knowledge graph embeddings. We propose a simple disjoint cross-validation scheme to evaluate drug-drug interaction predictions for the scenarios where the drugs have no known DDIs.

RESULTS

We designed different evaluation settings to accurately assess the performance for predicting DDIs. The settings for disjoint cross-validation produced lower performance scores, as expected, but still were good at predicting the drug interactions. We have applied Logistic Regression, Naive Bayes and Random Forest on DrugBank knowledge graph with the 10-fold traditional cross validation using RDF2Vec, TransE and TransD. RDF2Vec with Skip-Gram generally surpasses other embedding methods. We also tested RDF2Vec on various drug knowledge graphs such as DrugBank, PharmGKB and KEGG to predict unknown drug-drug interactions. The performance was not enhanced significantly when an integrated knowledge graph including these three datasets was used.

CONCLUSION

We showed that the knowledge embeddings are powerful predictors and comparable to current state-of-the-art methods for inferring new DDIs. We addressed the evaluation biases by introducing drug-wise and pairwise disjoint test classes. Although the performance scores for drug-wise and pairwise disjoint seem to be low, the results can be considered to be realistic in predicting the interactions for drugs with limited interaction information.

The prevalence and severity of potential drug-drug interactions among adult polypharmacy patients at outpatient clinics in Jordan

Objective

To assess the prevalence of potential drug-drug interactions (pDDIs) among polypharmacy patients in Jordan using Lexicomp®. Additionally, this study aims to categorize and rate the identified pDDIs according to interaction risk, severity, and reliability.

Methods

A descriptive cross-sectional study was conducted at six different hospitals representing different public health sectors in Jordan (ministry of health, royal medical services, and university-affiliated hospitals). Polypharmacy patients from outpatient clinics (e.g., cardiology,& and internal medicine) were identified, recruited, and interviewed by clinical pharmacists. pDDIs were assessed using the Lexicomp® mobile application and classified according to interaction risk rating, severity, and reliability rating. Furthermore, the prevalence of pDDIs across chronic medical conditions was assessed. P-value <0.05 was considered as significant.

Results

A total of 801 patients with polypharmacy were identified. The average number of drugs per patient was 6.6 ± 1.96, with an average of 4.2 ± 3.0 pDDIs per patient. Potential drug-drug interactions were detected in 769 patients (96%), with a total of 3359 interactions. Blood pressure lowering agents were involved in 39.9% of the pDDIs. Cardiovascular system drugs contributed to the largest share of pDDIs (46.6%). While diuretics had the major share of interactions among cardiovascular system drugs (16.2%), drugs used in diabetes had the highest share across all groups (17.1%). The majority of pDDIs were of “C” risk rating with a moderate interaction severity, whilst 1.6% of pDDIs could have been avoided in the first place as the concurrent administration of these agents is contraindicated (i.e., risk rating X). Patients with cardiovascular diseases, diabetes, chronic obstructive pulmonary disease, gout, and chronic kidney disease were associated with the highest number of potential drug-drug interactions.

Conclusion

Our study showed that 96% of polypharmacy patients at outpatient clinics have at least one pDDI. Almost half of the detected interactions involved cardiovascular medications. The majority of these pDDIs had moderate severity, with no more than 10% of the interactions requiring therapy modification.

[Potential drug interactions in adults and the elderly in primary health care]

The objective of the present study was to characterize the potential drug interactions (PDI), estimating the factors associated to their occurrence in adults and the elderly assisted by the Programa Médico de Família de Niterói, Rio de Janeiro. This is a sub-study of STUDY DIGITALIS, which included individuals enrolled in the Niteroi Family Medical Program (45-99 years). In this study, 341 individuals with a prescription of two or more drugs were analyzed. The classification of PDI followed MICROMEDEX. There were 113 different interactions. Of the total number of individuals, 63.6% had at least one PDI. The variables with higher probability of PDI were: lower level of schooling; income less than R$800.00; absence of health plan; previous diagnosis of hypertension and diabetes; use of 5 or more medications prescribed. After adjustment, the variables previous diagnosis of hypertension and diabetes and use of 5 or more prescription drugs remained statistically significant. Careful management of primary care treatment with monitoring is important in patients with PDI, especially in patients who are more susceptible.

Drug interactions among older adults followed up in a comprehensive medication management service at Primary Care

Objective:

To estimate the prevalence of drug interactions and associated factors among older adults followed up in a Comprehensive Medication Management Service at Primary Care.

Methods:

Firstly, the Beers criteria 2015 was used to define drug interactions; later, drug interactions proposed by Dumbreck for patients with diabetes, depression, and heart failure were evaluated. The associated factors were assessed by univariate (Pearson's χ²) and multivariate analyses (logistic regression). The significance level of 5% was set for all analyses.

Results:

The mean age of the studied population was 70.2±7.8 years; 52.2% were between 60 and 69 years, and 61.3% were female. Among the older adults, 94.5% used two or more drugs (condition for the occurrence of drug-drug interaction). The prevalence of drug interaction according to the Beers criteria was 4.9%. After multivariate analysis, diseases of the central nervous system, arrhythmia, number of medications, and female sex were positively associated with drug interaction. The prevalence of drug interaction according to Dumbreck was 27.2%. After multivariate analysis, the number of medications, the presence of heart failure, and Charlson comorbidity index greater than 1 were conditions positively associated with drug interactions.

Conclusion:

The holistic and individualized approach used in comprehensive medication management services for older patients is important, considering the prevalence of drug interactions and the need to minimize adverse events.

Challenges and innovations of delivering medicines to older adults

Older adults with multimorbidity, polypharmacy, and complex health needs are the major consumer of health care. Ensuring that medicines are used safely, effectively, and delivered efficiently in this population is challenging. In this context, the approach to medicines delivery should seek to overcome some of the difficulties of delivering medicines to older people, and ensure each medication is delivered by the optimal and most convenient route for the patient in question. However, this poses significant obstacles, as the development of medicines suitable for use in older populations does not often account for complex health needs, potential challenges in relation to drug disposition, safety of excipients and limitations with practical usability of dosage forms. The objective of this review is to summarise and discuss current challenges and novel approaches to delivering medications to older adults.

Detection of drug-drug interactions through data mining studies using clinical sources, scientific literature and social media

Drug-drug interactions (DDIs) constitute an important concern in drug development and postmarketing pharmacovigilance. They are considered the cause of many adverse drug effects exposing patients to higher risks and increasing public health system costs. Methods to follow-up and discover possible DDIs causing harm to the population are a primary aim of drug safety researchers. Here, we review different methodologies and recent advances using data mining to detect DDIs with impact on patients. We focus on data mining of different pharmacovigilance sources, such as the US Food and Drug Administration Adverse Event Reporting System and electronic health records from medical institutions, as well as on the diverse data mining studies that use narrative text available in the scientific biomedical literature and social media. We pay attention to the strengths but also further explain challenges related to these methods. Data mining has important applications in the analysis of DDIs showing the impact of the interactions as a cause of adverse effects, extracting interactions to create knowledge data sets and gold standards and in the discovery of novel and dangerous DDIs.

Clinically relevant drug-drug interactions among elderly people with dementia

Purpose

Increased numbers of drugs and changes in pharmacokinetic and pharmacodynamic parameters among elderly people contribute to increased prevalence of adverse drug reactions. Drug–drug interactions (DDIs) are an important reason for admission to hospital and elderly people with dementia are particularly vulnerable. The aims of the present study were to assess the occurrence and characteristics of clinically relevant DDIs and to investigate potential risk factors associated with DDIs among elderly people with dementia.

Methods

People ≥ 65 years with dementia, admitted to two hospitals in Northern Sweden, were included. The medical records of 458 patients were reviewed. Clinically relevant DDIs were identified using the Janusmed interactions database. Pharmacological classification was conducted using Stockley’s classification system.

Results

A total of 401 DDIs were identified among 43.2% of the study population, of which 98.5% had interactions that may require dose adjustment and 7.6% had drug combinations that should be avoided. Pharmacodynamic interactions were most common, of which furosemide–citalopram (n = 35) were most frequently observed. Omeprazol–citalopram (n = 25) was the most common drug combination among pharmacokinetic interactions. Citalopram and warfarin were the most commonly involved drug substances. An association was found between a higher number of medications being prescribed and having at least one DDI.

Conclusion

Clinically relevant drug–drug interactions are prevalent among elderly people with dementia living in Northern Sweden. Drug–drug interactions should be identified in order to manage and prevent adverse outcomes. This is particularly important among this group of people especially when multiple medications are being prescribed.

Detection and analysis of drug-drug interactions among hospitalized cardiac patients in the Mohammed V Military Teaching Hospital in Morocco

INTRODUCTION

Drug-drug interactions (DDIs) are defined as two or more drugs interacting in such a manner that the effectiveness or toxicity of one or more drugs is altered. Patients with cardiovascular disorders are at higher risk for DDIs because of the types and number of drugs they receive. The aim of the present study was to assess the prevalence of DDIs in patients admitted to the cardiology department of a hospital in Morocco.

METHODS

A prospective observational study from June 2016 to September 2016 was carried out in the cardiology department of a hospital in Morocco. Those patients who were taking at least two drugs and had a hospital stay of at least 48 hours were included in the study. The medications of the patients were analysed for possible interactions. All the prescriptions of the study population were screened for drug-drug interactions using a computerized DDI database system (Theriaque®).

RESULTS

During the study period, 138 patients were included; 360 interactions were detected among 94 patients, with an average number of drugs taken of 5.2. The prevalence of DDIs was estimated at 68.11%, the most common of which concerned Kardegic/Plavix (12.22%), Kardegic/Heparin (8.33%), and Lasilix/Spironolactone (5.83%). Among the 726 prescribed drugs, (372 [51.24%]) were drugs of the cardiovascular system, followed by blood and hematopoietic organ drugs (288 [39.67%]) according to the Anatomical Therapeutic Chemical Classification codes. These interactions were categorized on the basis of level of severity: interactions with major severity accounted for 11.11% (40) of the total DDIs while those with moderate and minor severity accounted for 37.22% (134) and 51.66% (186), respectively.

CONCLUSION

This study reports the prevalence of DDIs in patients admitted to the cardiology department of a hospital in Morocco. This study shows that DDIs are frequent among hospitalized cardiac patients and highlights the need to screen prescriptions of cardiovascular patients for possible DDIs, as this helps in their detection and prevention.Pan African Medical Journal - ISSN: 1937- 8688 (www.panafrican-med-journal.com)Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net)Pan African Medical Journal - ISSN: 1937- 8688 (www.panafrican-med-journal.com)Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net).

Potential Drug-Drug Interactions among Patients prescriptions collected from Medicine Out-patient Setting

Objective:

To identify and evaluate the frequency, severity, mechanism and common pairs of drug-drug interactions (DDIs) in prescriptions by consultants in medicine outpatient department.

Methods:

This cross sectional descriptive study was done by Pharmacology department of Bahria University Medical & Dental College (BUMDC) in medicine outpatient department (OPD) of a private hospital in Karachi from December 2015 to January 2016. A total of 220 prescriptions written by consultants were collected. Medications given with patient's diagnosis were recorded. Drugs were analyzed for interactions by utilizing Medscape drug interaction checker, drugs.com checker and stockley`s drug interactions index. Two hundred eleven prescriptions were selected while remaining were excluded from the study because of unavailability of the prescribed drugs in the drug interaction checkers.

Results:

In 211 prescriptions, two common diagnoses were diabetes mellitus (28.43%) and hypertension (27.96%). A total of 978 medications were given. Mean number of medications per prescription was 4.6. A total of 369 drug-drug interactions were identified in 211 prescriptions (175%). They were serious 4.33%, significant 66.12% and minor 29.53%. Pharmacokinetic and pharmacodynamic interactions were 37.94% and 51.21% respectively while 10.84% had unknown mechanism. Number wise common pairs of DDIs were Omeprazole-Losartan (S), Gabapentine- Acetaminophen (M), Losartan-Diclofenac (S).

Conclusion:

The frequency of DDIs is found to be too high in prescriptions of consultants from medicine OPD of a private hospital in Karachi. Significant drug-drug interactions were more and mostly caused by Pharmacodynamic mechanism. Number wise evaluation showed three common pairs of drugs involved in interactions.

Potential drug-drug interactions and their risk factors in pediatric patients admitted to the emergency department of a tertiary care hospital in Mexico

Background

Drug-drug interactions (DDIs) detected in a patient may not be clinically apparent (potential DDIs), and when they occur, they produce adverse drug reactions (ADRs), toxicity or loss of treatment efficacy. In pediatrics, there are only few publications assessing potential DDIs and their risk factors. There are no studies in children admitted to emergency departments (ED). The present study estimates the prevalence and describes the characteristics of potential DDIs in patients admitted to an ED from a tertiary care hospital in Mexico; in addition, potential DDI-associated risk factors are investigated.

Methods

A secondary analysis of data from 915 patients admitted to the ED of the Hospital Infantil de México “Federico Gómez” was conducted. The Medscape Drug Interaction Checker software was used to identify potential DDIs. The results are expressed as number of cases (%), means (95% CI) and medians (25-75^th percentiles). Count data regressions for number of total and severity-stratified potential DDIs were performed adjusting for patient characteristics, number of administered drugs, days of stay, presence of ADRs and diagnoses.

Results

The prevalence of potential DDIs was 61%, with a median of 4 (2–8). A proportion of 0.2% of potential DDIs was “Contraindicated”, 7.5% were classified as “Serious”, 62.8% as “Significant” and 29.5% as “Minor”. Female gender, age, days of stay, number of administered drugs and diagnoses of Neoplasms (C00-D48), Congenital malformations (Q00-Q99), Diseases of the Blood, Blood-forming Organs and Immunity (D50-D89) and Diseases of the nervous system (G00-G99) were significantly associated with potential DDIs.

Conclusion

The prevalence of potential DDIs in the ED is high, and strategies should therefore be established to monitor patients’ safety during their stay, in addition to conducting investigations to estimate the real harm potential DDIs inflict on patients.

A Prospective Analysis of Drug Interactions in Patients of Intensive Cardiac Care Unit

INTRODUCTION

Drug-Drug Interaction (DDI) is a serious concern in cardiac patients due to polypharmacy.

AIM

The present study was aimed to identify the potential DDI among hospitalized cardiac patients and evaluate the mechanism and severity of such interactions.

MATERIALS AND METHODS

A prospective observational study was conducted in intensive cardiac care unit of a tertiary care hospital for six months. Patients aged 18 years and above and taking two or more drugs were included in the study. Medscape drug interaction checker was used to identify and analyze the pattern of potential DDI.

RESULTS

Out of 500 patients, most of the patients were male (78.4%) in the age group of 50-60 years (31%). The most common diagnosis was acute coronary syndrome (57.2%). Out of total 2849 DDI, 2194 (77.01%) were pharmacodynamic, 586 (20.57%) were pharmacokinetic in nature while 69 (2.42%) drug pairs interacted by unknown mechanism. Majority of drug interactions were significant {2031 (71.29%)} in nature followed by minor {725(25.45%)} while serious drug interactions were observed in only 93 (3.26%) drug pairs. A positive correlation was observed between patient's age and number of drugs prescribed (r=0.178, p<0.001), number of drugs prescribed and potential Drug-Drug Interaction (pDDI) (r= 0.788, p<0.001) and between patient's age and pDDI (r=0.338, p<0.001).

CONCLUSION

The risk of pDDI was more commonly observed in elderly male patients particularly with antiplatelet drugs like low dose aspirin and clopidogrel.

Incidence of Potential Drug-Drug Interactions in a Limited and Stereotyped Prescription Setting - Comparison of Two Free Online Pharmacopoeias

BACKGROUND

Drug-drug interactions (DDIs) are very common adverse events in health care delivery settings. The use of electronic pharmacopeias can potentially reduce the incidence of DDIs, but they are often thought to be cumbersome to use. This study is aimed at studying the incidence of potential DDIs in a surgical department, where a limited number of drugs are used in stereotyped combinations. We also compared two popular drug compendia in detecting potential DDIs.

METHODS

The prescriptions of selected patients were entered into Epocrates® and Medscape® for Android smartphones. Potential DDIs were generated and their categories were noted. The warnings generated by Epocrates® were compared with those generated by Medscape® and an agreement index was calculated.

RESULTS

Three hundred and thirty-one patients were included for analysis who had received a total of 2,878 drug orders. The incidence of potential DDIs was very high - 89% of all prescriptions. Phenytoin was the drug most commonly implicated, followed by furosemide. Of the DDIs detected, 0.14% were potentially serious and the drug combinations were contraindicated. There was a significant discrepancy between the categories of potential DDIs detected by Epocrates® and Medscape®. No clinically significant DDI was detected in any patient in this cohort.

CONCLUSIONS

Despite routinely using only a limited number of drugs in stereotyped combinations, prescriptions in surgical departments may not be immune from a significant incidence of DDIs. The use of free apps could reduce the incidence of DDIs, enhance patient safety, and also aid in educating trainees.

Potential drug-drug interaction in Mexican patients with schizophrenia

OBJECTIVE

The aim of this study was to observe potential drug-drug interactions in the medication of Mexican schizophrenic patients.

METHODS

We performed a retrospective and cross-sectional study that was carried out in a psychiatric clinic. Only the prescriptions of patients with schizophrenia whose diagnoses were based on the DSM-IV instrument were included in this study. The Drug Interactions Checker software ( http://www.drugs.com/drug_interactions.html ) was used in this study to analyse potential drug-drug interactions.

RESULTS

In total, 86 of 126 patients were at risk of potential drug-drug interactions. Haloperidol and biperiden was the most common drug pair of 232 pairs evaluated. In our study, 13.8% of drug-drug interaction showed a major level of severity, whereas in 83.2%, the interaction was moderate. Finally, central nervous system (CNS) depression and anticholinergic effect were the main possible effects of drug-drug interaction.

CONCLUSIONS

Our results revealed a high number of patients with schizophrenia receiving two or more drugs. The potential drug-drug interactions observed in the Mexican population are consistent with the concomitant use of antipsychotics, benzodiazepines, and antidepressants prescribed in schizophrenia that could cause central nervous system (CNS) depression and anticholinergic effect. Drug-drug interaction must be considered when the patient with schizophrenia is medicated.

Severe potential drug-drug interactions in older adults with dementia and associated factors

OBJECTIVE

To identify the main severe potential drug-drug interactions in older adults with dementia and to examine the factors associated with these interactions.

METHOD

This was a cross-sectional study. The enrolled patients were selected from six geriatrics clinics of tertiary care hospitals across Mexico City. The patients had received a clinical diagnosis of dementia based on the current standards and were further divided into the following two groups: those with severe drug-drug interactions (contraindicated/severe) (n=64) and those with non-severe drug-drug interactions (moderate/minor/absent) (n=117). Additional socio-demographic, clinical and caregiver data were included. Potential drug-drug interactions were identified using Micromedex Drug Reax 2.0® database.

RESULTS

A total of 181 patients were enrolled, including 57 men (31.5%) and 124 women (68.5%) with a mean age of 80.11±8.28 years. One hundred and seven (59.1%) patients in our population had potential drug-drug interactions, of which 64 (59.81%) were severe/contraindicated. The main severe potential drug-drug interactions were caused by the combinations citalopram/anti-platelet (11.6%), clopidogrel/omeprazole (6.1%), and clopidogrel/aspirin (5.5%). Depression, the use of a higher number of medications, dementia severity and caregiver burden were the most significant factors associated with severe potential drug-drug interactions.

CONCLUSIONS

Older people with dementia experience many severe potential drug-drug interactions. Anti-depressants, antiplatelets, anti-psychotics and omeprazole were the drugs most commonly involved in these interactions. Despite their frequent use, anti-dementia drugs were not involved in severe potential drug-drug interactions. The number and type of medications taken, dementia severity and depression in patients in addition to caregiver burden should be considered to avoid possible drug interactions in this population.

[Potential drug-drug interactions among elderly using antihypertensives from the Brazilian List of Essential Medicines]

The aim of this study was to estimate the prevalence of potential interactions between antihypertensives and other drugs. A household survey was conducted with individuals 60 years or older residing in Rio de Janeiro, Brazil. Potential moderately or very severe drug-drug interactions with antihypertensives, documented as suspected, probable or established, were identified. A total of 577 elderly were interviewed (mean age = 72 years), 45.2% of whom were using antihypertensives, of which 31.0% were subject to potential drug-drug interactions. Most of the interactions were moderately severe. Compared to the other elderly, those with potential drug-drug interactions showed more than fourfold odds of using five or more medicines and more than twofold odds of having been hospitalized in the previous year. Among the most frequent pairs of interactions, 75% cause a reduction in the hypotensive effect (65/87), which can result in low effectiveness of blood pressure control, prescribing of more drugs, and risk of other adverse events and interactions.

Prevalence of potential drug-drug interactions among internal medicine ward in University of Gondar Teaching Hospital, Ethiopia

OBJECTIVE

To determine the prevalence, clinical significance and the associated risk factors of potential drug-drug interactions (DDIs) at internal medicine ward of University of Gondar (UOG) hospital.

METHOD

A prospective cross-sectional study was conducted on patients treated in internal medicine ward of UOG hospital from April 29, 2013 to June 2, 2013. Data was collected from medical records and by interviewing the patients face to face. Descriptive analysis was conducted for back ground characteristics and logistic regression was used to determine the associated risk factors.

RESULT

In our study, we have identified a total number of 413 potential DDIs and 184 types of interacting combinations with 4.13 potential DDIs per patient. Among 413 potential DDIs most were of moderate interactions 61.2% (n=253) followed by 26% (n=107) of minor interactions and 12.8% (n=53) of major interactions. There was significant association of occurrence of potential DDIs only with taking three or more medications.

CONCLUSION

We have recorded a high rate of prevalence of potential DDI in the internal medicine ward of UOG hospital and a high number of clinically significant DDIs which the most prevalent DDI were of moderate severity. Careful selection of drugs and active pharmaceutical care is encouraged in order to avoid negative consequences of these interactions.

A study of potential adverse drug-drug interactions among prescribed drugs in medicine outpatient department of a tertiary care teaching hospital

Objective:

To evaluate prevalence, types, and severity of potential adverse drug-drug interaction in medicine out-patient department.

Materials and Methods:

A single-point, prospective, and observational study was carried out in medicine OPD. Study began after obtaining approval Institutional Ethics Committee. Data were collected and potential drug-drug interactions (pDDIs) were identified using medscape drug interaction checker and were analyzed.

Result:

A total of 350 prescriptions with mean age 52.45 ± 14.49 years were collected over a period of 5 months. A total of 2066 pDDIs were recorded with mean of 5.90 ± 6.0. The prevalence of pDDI was 83.42%. Aspirin was most frequently prescribed drug in 185 (10.15%) out of total of 1821 drugs It was also the most frequent drug implicated in pDDI i.e. in 48.16%. The most common pDDI identified was metoprolol with aspirin in 126 (6.09%). Mechanism of interactions was pharmacokinetic in 553 (26.76%), pharmacodynamic in 1424 (68.92%) and 89 (4.30%) having an unknown mechanism. Out of all interactions, 76 (3.67%) were serious, 1516 (73.37%) significant, and 474 (22.94%) were minor interaction. Age of the patients (r = 0.327, P = 0.0001) and number of drugs prescribed (r = 0.714, P = 0.0001) are significantly correlated with drug interactions.

Conclusion:

Aspirin being the most common drug interacting. The use of electronic decision support tools, continuing education and vigilance on the part of prescribers toward drug selection may decrease the problem of pDDIs.

Prevalência e fatores associados a potenciais interações medicamentosas entre idosos em um estudo de base populacional

Objetivo: Determinar a prevalência de potenciais interações medicamentosas e os fatores a elas associados entre idosos cadastrados nas equipes da Estratégia Saúde da Família (ESF) do município de Timóteo, MG. Métodos: Estudo transversal, utilizando amostragem aleatória estratificada. Foram realizadas 273 entrevistas domiciliares, com indivíduos de 60 anos ou mais de idade, por meio de formulário que continha perguntas de identificação, sociodemográficas e questões relacionadas às condições de saúde do idoso e ao consumo de medicamentos. As interações medicamentosas foram identificadas e classificadas de acordo com o software Micromedex®. Resultados: A prevalência de potenciais interações medicamentosas foi de 55,6%, perfazendo um total de 466 ocorrências, das quais 5,6% eram leves, 81,6% eram moderadas e 12,8% eram de maior gravidade. As classes terapêuticas mais frequentemente envolvidas foram anti-inflamatórios e, principalmente, fármacos utilizados em doenças cardiovasculares. A ausência de internação hospitalar nos últimos 4 meses associou-se significativamente a uma menor chance de interações graves, e a maior parte dos pacientes que não tiveram nenhum tipo de interação moderada utilizava apenas medicamentos prescritos por médicos. Conclusões: A prevalência de interações medicamentosas encontrada foi semelhante à descrita na literatura, demonstrando alta frequência entre idosos. A ausência de internação hospitalar prévia e a prescrição de medicamentos por profissionais médicos associaram-se a uma menor frequência desse fenômeno. A prescrição de múltiplos medicamentos simultaneamente aos idosos pode comprometer a segurança e a saúde dessa população, requerendo, por parte dos cuidadores, observação atenta quanto à ocorrência de interações medicamentosas.

A study of potential drug-drug interactions among hospitalized cardiac patients in a teaching hospital in Western Nepal

AIM

Drug-drug interaction (DDI) is of major concern in patients with complex therapeutic regimens. The involvement of cardiovascular medicines in drug interaction is even higher. However, reports of DDI between these groups of drugs are few. The study aims to identify the potential DDI among hospitalized cardiac patients. Furthermore, we assessed the possible risk factors associated with these interactions.

SUBJECTS AND METHODS

The Type of study prospective observational study was conducted from May 2012 to August 2012 among hospitalized cardiac patients. Cardiac patients who were taking at least two drugs and who had a hospital stay of at least 24 h were enrolled. The medications of the patients were analyzed for possible interactions using the standard drug interaction database - Micromedex -2 (Thomson Reuters) × 2.0.

RESULTS

From a total of 150 enrolled patients, at least one interacting drug combination was identified among 32 patients. The incidence of potential DDI was 21.3%. A total of 48 potentially hazardous drug interactions were identified. Atorvastatin/azithromycin (10.4%), enalapril/metformin (10.4%), enalapril/potassium chloride (10.4%), atorvastatin/clarithromycin (8.3%) and furosemide/gentamicin (6.3%) were the most common interacting pairs. Drugs most commonly involved were atorvastatin, enalapril, digoxin, furosemide, clopidogrel and warfarin. Majority of interactions were of moderate severity (62.5%) and pharmacokinetic (58.3%) in nature. Increased number of medicines, prolonged hospital stays and comorbid conditions were the risk factors found associated with the potential DDI.

CONCLUSIONS

This study highlighted the need of intense monitoring of patients who have identified risk factors to help detect and prevent them from serious health hazards associated with drug interactions.

Avaliação de interações medicamentosas potenciais em prescrições da atenção primária de Vitória da Conquista (BA), Brasil

As interações medicamentosas são fatores de risco para a ocorrência de reações adversas a medicamentos. Este estudo teve o objetivo de avaliar as interações medicamentosas potenciais em prescrições da atenção primária de Vitória da Conquista (BA), visando preencher a lacuna de conhecimento sobre essa temática no Brasil. Foram coletadas informações sobre diversas variáveis de prescrições oriundas da atenção primária e as interações medicamentosas avaliadas a partir dos bancos de dados do Medscape e Micromedex(r). Verificou-se ainda a frequência de polifarmácia e associação desta com a ocorrência de interações medicamentosas. Os resultados mostraram frequência de 48,9% de interações medicamentosas, 74,9% delas de gravidade moderada ou maior, e 8,6% de prescrições em polifarmácia que, em teste qui-quadrado, mostrou associação positiva com ocorrência de interações medicamentosas potenciais (p < 0,001). As prescrições oriundas da atenção primária de Vitória da Conquista (BA) apresentaram uma alta frequência de interações medicamentosas, porém faz-se necessária a análise de outros fatores de risco para ocorrência destas nesse nível de atenção à saúde.

Drug-drug interactions and their predictors: Results from Indian elderly inpatients

Background

In view of the multiple co-morbidities, the elderly patients receiving drugs are prone to suffer with drug interactions since they receive a greater number of drugs.

Objective

The study was undertaken to determine the prevalence of drug interactions, as well as their predictors.

Methods

The prescriptions of a total of 1510 inpatients were collected prospectively for 1.5 years from inpatients wards of public tertiary care teaching hospital. All the prescriptions were checked for drug interactions using the Micromedex® Drug-Reax database-2010 and Stockley’s Drug Interactions. Regression analyses sought to determine predictors for the drug interaction.

Results

The patients, with the average age of 67.2 ±0.2 years, were prescribed an average of 9.15 ±0.03 medications. It was found that out of 1510 prescriptions of inpatients, 126 (8.3%) prescriptions had one or more than one drug interaction. All the identified interactions were severe in nature. The top most interacting drugs were acetylsalicylic acid and anticoagulant (n=59). The second top most interacting drug combination was clopidogrel and proton pump inhibitors (n=51). The most commonly involved drugs in interactions were C (cardiovascular system) and A (alimentary tract and metabolism). Using multivariate binary logistic regression, multiple drugs (Odds Ratio=4.5; 95% Confidence Interval: - 2.38 -9.47) and multiple diagnoses (Odds Ratio=2.6; 95%CI: -1.40 -5.57) were found to be significant predictors for drug interaction.

Conclusions

The results of this study substantiate the occurrence of severe drug interactions among Indian elderly inpatients. In order to provide safer pharmaceutical care, the active involvement of clinical pharmacists is a potential option.

Potential drug-drug interactions in internal medicine wards in hospital setting in Pakistan

BACKGROUND

Multiple drugs therapies may be the potential source of drug-drug interactions that can result in alteration of therapeutic response and/or increase untoward effects of many drugs.

OBJECTIVE

To identify the frequency and levels of potential drug-drug interactions (pDDIs) in internal medicine wards and their association with patients' age, gender, length of hospital stay and number of prescribed medications; and to describe management of frequently identified major or moderate pDDIs.

SETTING

Internal medicine wards of two major tertiary care hospitals of Khyber Pakhtunkhwa, Pakistan.

METHOD

Micromedex Drug-Reax system was used to screen patient's profiles for pDDIs. Logistic regression was applied to determine the odds ratio for specific risk factors of pDDIs i.e., age, gender, hospital-stay and number of medications.

MAIN OUTCOME MEASURE

Overall prevalence and prevalence of contraindicated, major, moderate and minor pDDIs; levels of pDDIs; frequently identified major or moderate interactions; and odds ratios for risk factors.

RESULTS

Total, 188 interacting drug-combinations were identified that contributed to 675 pDDIs. Of 400 patients, 52.8% patients were presented with at least one pDDI (overall prevalence), 21.3% with at least one major-pDDI, and 44.3% with at least one moderate-pDDI. Of 675 pDDIs, most were of moderate (63.6%) or major severity (23%); good (61.2%) or fair (25.5%) type of scientific evidence; and delayed onset (50.2%). Most frequently identified major or moderate interactions resulted in 45.3% of all pDDIs. Their potential adverse outcomes included hepatotoxicity, bleeding, ototoxicity, nephrotoxicity, hypoglycemia, hyperglycemia, risk of thrombosis, hypotension, cardiac arrhythmias and reduction in therapeutic-effectiveness. There was significant association of the occurrence of pDDIs with patients' age of 60 years or more (OR = 2.1; 95% CI = 1.3-3.3; p = 0.003), hospital stay of 6 days or longer (OR = 2.6; 95% CI = 1.5-4.5; p = 0.001), and seven or more number of prescribed medications (OR = 5.9; 95% CI = 3.6-9.6; p < 0.001).

CONCLUSION

The present study has recorded a high prevalence of pDDIs in internal medicine wards. Patients with old age, longer hospital stay and increased number of prescribed medications were at higher risk.

How many potential drug-drug interactions cause adverse drug reactions in hospitalized patients?

BACKGROUND

Potential drug-drug interactions (DDIs) are frequent in drug prescription but clinically significant are the ones which can result in changes of therapeutic effect of one of the two drugs or in adverse drug reactions (ADRs). The aim of this study was to assess the potential DDIs as well as the DDIs which cause adverse drug reactions (ADRs) in an internal medicine department hospitalized patients.

METHODS

The prospective study included all patients admitted between November 2010 and January 2011 in an internal medicine ward. Information on patients' demographics and their medication use history was obtained from each patient by interview. In addition, medical history, medication use during hospitalization, and relevant laboratory and clinical data were obtained from medical records. Potential DDIs were identified using the Thomson Micromedex program. Each patient was monitored during the hospitalization period in order to detect the ADRs resulting from DDI's if present.

RESULTS

Three hundred and five patients were enrolled in this study during 3 months. Of 1279 potential DDIs, Fourteen led to 13 ADRs out of which 8 were serious and caused hospital admission or prolongation of hospitalization. There was a statistically significant association between ADRs related to DDIs and the presence of ATC (Anatomical Therapeutic Chemical) C medication during hospitalization and the length of hospital stay, in the multivariate analysis.

CONCLUSION

Awareness of the most commonly occurring DDIs should be raised by the utilization of drug-drug interaction guides in the Romanian clinical practice which can help prescribers and pharmacists prevent DDI related ADRs.

Prevalence of potential drug interactions in an Iranian general hospital

The hazards of prescribing many drugs, including side-effects, drug-drug interactions and difficulties of compliance have long been recognized as particular problems when prescribing. This study estimates the rate and factors associated with potential drug-drug interactions in prescriptions from wards of An Iranian General Hospital. Data were retrieved from the pharmacy of a general hospital (200 beds) during one year period 2010. Potential drug-drug interaction were identified using a computerized drug-drug interaction database system (Prescription Analyzer 2000, Sara Rayane Co., Iran). Patients of both genders and 15 years-old or more were included in this study. Prescriptions with two or more drugs prescribed were selected during one year period 2010. Gender number of drugs and therapeutic drug classes on prescriptions were explored as associated factors to drug-drug interaction. The overall prevalence of potential drug-drug interaction was 20.3%. The risks of severe potential drug interactions were relatively high and the rate of potential drug-drug interaction was significantly higher in women (60.6%) and the patients aged over 60 years old (57.1%). The frequency of the potentially severe drug-drug interaction was 10.8% with digoxin-furosemide as the most common interacting pair (5.91%). A positive correlation was found between drug-drug interaction, patient's age, number of drugs and drugs acting on cardiovascular system. So cardiology women inpatients, age more then 60 years old, and patients prescribed digoxin and angiotensin-converting enzyme inhibitors should be closely monitored for adverse outcomes from drug-drug interaction.

Assessment of Drug-Drug Interactions among Renal Failure Patients of Nephrology Ward in a South Indian Tertiary Care Hospital

Polypharmacy is common in drug prescriptions of chronic kidney disease patients. A study of the prescription patterns of drugs with potential interactions would be of interest to prevent drug related adverse events. A prospective observational study of six months (Dec 2009-May 2010) was carried out among the chronic kidney disease patients admitted to the nephrology ward of a South Indian tertiary care hospital. The pattern and rates of drug-drug interactions seen in the prescriptions of these patients was studied. Among the 205 prescriptions included, a total of 474 interactions were reported, making 2.7 interactions per prescription with incidence rates of 76.09%. Around 19.62% of interactions were of major severity. Most common interactions were found between ascorbic acid and cyanocobalamine (12.45%), clonidine and metoprolol (3.80%) respectively. Hypo or hypertension (31.65%), decreased drug efficacy (29.11%) and hypo or hyperglycemia (14.14%), were the most commonly reported clinical outcomes of the drug interactions. Cardiovascular drugs (calcium channel blockers and beta blockers; 52%) constitute the major class of drugs involved in interactions. As most of the interactions had a delayed onset, long term follow-up is essential to predict the clinically significant outcomes of these interactions. Hence, drug interactions are commonly seen in the prescriptions of chronic kidney disease patients which can lead to serious adverse events if not detected early. Need for collaboration with a clinical pharmacist and electronic surveillance, which are absent in developing countries like India, is emphatic.

Potential drug-drug interactions in prescriptions to patients over 45 years of age in primary care, southern Brazil

BACKGROUND

Few cross-sectional studies involving adults and elderly patients with major DDIs have been conducted in the primary care setting. The study aimed to investigate the prevalence of potential drug-drug interactions (DDIs) in patients treated in primary care.

METHODOLOGY/PRINCIPAL FINDINGS

A cross-sectional study involving patients aged 45 years or older was conducted at 25 Basic Health Units in the city of Maringá (southern Brazil) from May to December 2010. The data were collected from prescriptions at the pharmacy of the health unit at the time of the delivery of medication to the patient. After delivery, the researcher checked the electronic medical records of the patient. A total of 827 patients were investigated (mean age: 64.1; mean number of medications: 4.4). DDIs were identified in the Micromedex® database. The prevalence of potential DDIs and major DDIs was 63.0% and 12.1%, respectively. In both the univariate and multivariate analyses, the number of drugs prescribed was significantly associated with potential DDIs, with an increasing risk from three to five drugs (OR = 4.74; 95% CI: 2.90-7.73) to six or more drugs (OR = 23.03; 95% CI: 10.42-50.91). Forty drugs accounted for 122 pairs of major DDIs, the most frequent of which involved simvastatin (23.8%), captopril/enalapril (16.4%) and fluoxetine (16.4%).

CONCLUSIONS/SIGNIFICANCE

This is the first large-scale study on primary care carried out in Latin America. Based on the findings, the estimated prevalence of potential DDIs was high, whereas clinically significant DDIs occurred in a smaller proportion. Exposing patients to a greater number of prescription drugs, especially three or more, proved to be a significant predictor of DDIs. Prescribers should be more aware of potential DDIs. Future studies should assess potential DDIs in primary care over a longer period of time.

Clinically important drug-drug interactions in primary care

WHAT IS KNOWN AND OBJECTIVE

Drug-drug interactions (DDIs) cause considerable morbidity and mortality worldwide and may lead to hospital admission. Sophisticated computerized drug information and monitoring systems, more recently established in many of the emerging economies, including Malaysia, are capturing useful information on prescribing. Our aim is to report on an investigation of potentially serious DDIs, using a university primary care-based system capturing prescription records from its primary care services.

METHODS

We retrospectively collected data from two academic years over 20 months from computerized databases at the Universiti Sains Malaysia (USM) from users of the USM primary care services.

RESULTS AND DISCUSSION

Three hundred and eighty-six DDI events were observed in a cohort of 208 exposed patients from a total of 23,733 patients, representing a 2-year period prevalence of 876·4 per 100,000 patients. Of the 208 exposed patients, 138 (66·3%) were exposed to one DDI event, 29 (13·9%) to two DDI events, 15 (7·2%) to three DDI events, 6 (2·9%) to four DDI events and 20 (9·6%) to more than five DDI events. Overall, an increasing mean number of episodes of DDIs was noted among exposed patients within the age category ≥70 years (P=0·01), an increasing trend in the number of medications prescribed (P<0·001) and an increasing trend in the number of long-term therapeutic groups (P<0·001).

WHAT IS NEW AND CONCLUSION

We describe the prevalence of clinically important DDIs in an emerging economy setting and identify the more common potentially serious DDIs. In line with the observations in developed economies, a higher number of episodes of DDIs were seen in patients aged ≥70 years and with more medications prescribed. The easiest method to reduce the frequency of DDIs is to reduce the number of medications prescribed. Therapeutic alternatives should be selected cautiously.