Potential drug interactions in elderly cancer patients

Polypharmacy and drug interactions in older patients with cancer receiving chemotherapy: associated factors

BACKGROUND

Polypharmacy in older adults with cancer receiving chemotherapy leads to increased risks of drug interactions, translating in potential hazardous health outcomes. This study aims to assess the prevalence of polypharmacy, drug-drug interactions (DDIs), and severe-drug interactions (SDIs) in older patients with cancer. Antineoplastic agents (ANAs) involvement and possible risk contexts (comorbidities with cardiac risk, and high-risk medications) were also analysed.

METHODS

Observational study with older adults (≥ 65 years) diagnosed with cancer, who were treated with antineoplastic agents (ANAs); it was conducted in three hospitals from the north of Portugal. Data collection was obtained using self-reports and medical records. DDIs were identified and classified using Micromedex® software. Descriptive and association analyze statistics were performed. Statistical hypothesis tests with p value less than 0.05 were considered significant. All statistical procedures and analysis were performed with R version 4.1.3.

RESULTS

We enrolled 552 patients. Polypharmacy prevalence was 88.40%; 76.45% and 56.16% of the patients presented with DDIs and SDIs, respectively. SDIs with ANAs were found in 21.20% of the patients. High-risk medications were associated with a higher risk of polypharmacy, DDIs, and SDIs. Polypharmacy and DDIs were higher in patients with hypertension or diabetes. SDIs were higher in patients with diabetes.

CONCLUSION

Polypharmacy, potential DDIs and SDIs were highly prevalent in older adults with cancer. A careful review of the medication administered is necessary to decrease it. These findings warrant further research to optimize medication in this population and decrease problems related to medication, which may lead to emergency room visits and hospitalisations, compromising patient safety and/or ongoing treatments.

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

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

Potential drug-drug interaction and its determinants among patients with cancer receiving chemotherapy in oncology centres of Northwest Ethiopia: an institutional-based cross-sectional study

OBJECTIVE

The study was conducted to assess potential drug-drug interactions (PDDIs) and its determinants among patients with cancer receiving chemotherapy.

DESIGN AND SETTING

An institutional-based cross-sectional study was used. This study was conducted from 1 June 2021 to 15 December 2021, in Northwest Ethiopia oncology centres.

PARTICIPANTS

All eligible patients with cancer received a combination of chemotherapy.

OUTCOMES

The prevalence and severity of PDDIs were evaluated using three drug interaction databases. Characteristics of participants were presented, arranged and summarised using descriptive statistics. The predictors and outcome variables were examined using logistic regression. The cut-off point was a p value of 0.05.

RESULTS

Of 422 patients included in the study, 304 patients were exposed to at least one PDDI with a prevalence of 72.1% (95 % CI: 68% to 76%) using three drug interaction databases. There were varied reports of the severity of PDDI among databases, but the test agreement using the kappa index was 0.57 (95% CI: 0.52 to 0.62, p=0.0001) which is interpreted as a moderate agreement among three databases. Patients aged ≥50 years old had the risk to be exposed to PDDI by odds of 3.1 times (adjusted OR (AOR)=3.1, 95% CI (1.8 to 5.3); p=0.001) as compared with patients <50 years old. Similarly, patients with polypharmacy and comorbidity were more likely to be exposed to PDDI than their counterparts (AOR=2.4, 95% CI (1.4 to 4.1); p=0.002 and AOR=1.9, 95% CI (1.1 to 3.4); p=0.02, respectively).

CONCLUSION

The main finding of this study is the high prevalence of PDDI, signifying the need for strict patient monitoring for PDDIs among patients with cancer receiving chemotherapy. We suggest the use of at least three drug databases for quality screening. Patients with an age ≥50 years old, polypharmacy and comorbidity were significantly associated with PDDIs. The establishment of oncology clinical pharmacists and computerised reminder mechanisms for PDDIs through drug utilisation review is suggested.

Potential Drug Interactions in Terminally-Ill Cancer Patients, a Report from the Middle East

This study aims to evaluate the epidemiology of potential drug interactions in terminally-ill cancer patients receiving exclusively supportive care. In this cross-sectional study, during a 6-month follow-up, we considered the medical record of terminally-ill cancer patients referred to palliative care at the cancer center in Isfahan, Iran. Potential drug-drug interactions (DDIs) were assessed by Lexi-Interact ver.1.1 online software. During the study period, 133 terminally-ill cancer patients were recruited. We detected 1678 DDIs with moderate or major severity levels. Among them, 330, 219, 32, 1075, and 51 interactions were categorized in B, C, D, and X drug interactions categories, respectively. One hundred and twenty-two patients (91.73%) encountered at least one potential drug-drug interaction during the end of life care. Mechanistically, most drug-drug interactions (64.5%) were pharmacodynamics. The most frequent pharmacological class of drugs responsible for DDIs were quetiapine (91 cases), oxycodone (87 cases), and sertraline (55 cases). Interaction between oxycodone and sertraline was found to be in the top 10 detected DDIs (13.7%). Our results showed that potentially moderate or major drug-drug interactions often occur among terminally-ill cancer patients and the clinical significance of DDIs should be considered meticulously in the palliative care cancer setting.

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

BACKGROUND

A 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.

METHODS

To 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.

RESULTS

Among 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.

CONCLUSIONS

There 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.

Prevalence of Potential Pharmacological Interactions in Patients Undergoing Systemic Chemotherapy in a Tertiary Hospital

Introduction: Pharmacological interactions are frequently observed in patients with chronic diseases, and their occurrence is proportional to the amount of medication used daily. Patients undergoing chemotherapy treatment commonly have comorbidities, which favor a greater prevalence of polypharmacy, increasing the risk of drug interactions. Therefore, the aim of this study was to estimate the prevalence of drug interactions in patients undergoing intravenous chemotherapy treated at a hospital oncology service in southern Brazil. Methods: This was an observational study with a cross-sectional design that was carried out with the analysis of secondary data obtained through the review of medical records. The population assessed consisted of all cancer patients who received intravenous chemotherapy from October to December 2020. Results: Out of the 297 patients included in the study, 231 (77.8%) had at least 1 potential pharmacological interaction. In total, 1044 drug interactions were found that were classified according to severity, resulting in 18 (1.7%) contraindicated drug-drug interactions (DDI), 699 (67%) severe, 281 (26.9%) moderate, and 46 (4.4%) minor interactions. There was an association between polypharmacy and the prevalence of drug interactions. Conclusion: The results demonstrate that a large percentage of patients undergoing chemotherapy are susceptible to drug interactions. Thus, it is necessary that prescribers consider all drugs used by patients and, when possible, prescribe alternative drugs that have less potential for interaction in order to prevent drug interactions adverse effects and provide a better prognosis for patients.

Potential Drug Interactions Between Psychotropics and Intravenous Chemotherapeutics Used by Patients With Cancer

Introduction: Patients undergoing cancer treatment usually have comorbidities, and psychiatric disorders are commonly seen in these patients. For the treatment of these psychiatric disorders, the use of psychotropic drugs is common, turning these patients susceptible to untoward drug interactions. Therefore, the aim of this study was to estimate the prevalence of clinically relevant drug-drug interactions (DDI) between chemotherapeutic and psychotropic agents in patients with cancer treated at an oncology service in southern Brazil. Methods: An observational epidemiological study with a cross-sectional census-type design was carried out between October and December 2020. The drug-drug interactions were identified through consultation and analysis of the Medscape Drug Interaction Check and Micromedex databases. The interactions were classified as major, when the interaction can be fatal and/or require medical intervention to avoid or minimize serious adverse effects and moderate, when the interaction can exacerbate the patient's condition and/or requires changes in therapy. Results: A total of 74 patients was included in the study among the 194 patients seen in the oncology service during the period studied. A total of 24 (32.4%) DDIs were found, 21 (87.5%) of which were classified as being of major risk and 3 (12.5%) as moderate risk. According to the mechanism of action, 19 (79.1%) were classified as pharmacodynamic interactions and 5 (20.9%) as pharmacokinetic interactions. Conclusion: It was shown that a considerable percentage of patients undergoing intravenous chemotherapy are at risk of pharmacological interaction with psychotropic drugs. Thus, it is essential that the oncologist considers all psychotropic drugs and other drugs used by patients in order to avoid drug-drug interactions.

The Role of Ablative Radiotherapy in Older Adults With Limited Metastatic Disease

For patients with oligometastatic cancer, radiotherapy presents a promising avenue for achieving meaningful symptom relief and durable disease control. Data from recently published and ongoing randomized studies are helping to define the appropriate contexts for effective intervention with stereotactic ablative body radiotherapy (SABR) in the oligometastatic setting. Importantly, older adults represent a significant portion of patients with oligometastatic disease, yet often comprise a minority of patients in clinical trials. Moreover, older adults of the same chronologic age may have variable degrees of fitness and frailty. In this review, we highlight the specific challenges and considerations for the use of radiotherapy for older adults with oligometastatic disease-noting the importance of geriatric assessments in clinical decision-making about the appropriateness of SABR and other metastasis-directed therapies in this population. We then review data from existing trials, including a subset analysis of adverse events and survival estimates among older adults enrolled in the landmark SABR-COMET trial. Finally, we discuss future directions for research, including the need for focused clinical trials in older adult cohorts. Ultimately, a multidisciplinary approach is critical when carefully balancing the potential risks and benefits of this emerging treatment paradigm in the older adult population.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Real-life drug-drug and herb-drug interactions in outpatients taking oral anticancer drugs: comparison with databases

PURPOSE

Due to polypharmacy and the rising popularity of complementary and alternative medicines (CAM), oncology patients are particularly at risk of drug-drug interactions (DDI) or herb-drug interactions (HDI). The aims of this study were to assess DDI and HDI in outpatients taking oral anticancer drug.

METHOD

All prescribed and non-prescribed medications, including CAM, were prospectively collected by hospital pharmacists during a structured interview with the patient. DDI and HDI were analyzed using four interaction software programs: Thériaque^®, Drugs.com^®, Hédrine, and Memorial Sloan Kettering Cancer Center (MSKCC) database. All detected interactions were characterized by severity, risk and action mechanism. The need for pharmaceutical intervention to modify drug use was determined on a case-by-case basis.

RESULTS

294 patients were included, with a mean age of 67 years [55-79]. The median number of chronic drugs per patient was 8 [1-29] and 55% of patients used at least one CAM. At least 1 interaction was found for 267 patients (90.8%): 263 (89.4%) with DDI, 68 (23.1%) with HDI, and 64 (21.7%) with both DDI and HDI. Only 13% of the DDI were found in Thériaque^® and Drugs.com^® databases, and 125 (2.5%) were reported with similar level of risk on both databases. 104 HDI were identified with only 9.5% of the interactions found in both databases. 103 pharmaceutical interventions were performed, involving 61 patients (20.7%).

CONCLUSION

Potentially clinically relevant drug interaction were frequently identified in this study, showing that several databases and structured screening are required to detect more interactions and optimize medication safety.

Prevalence, severity, and nature of risk factors associated with drug-drug interactions in geriatric patients receiving cancer chemotherapy: A prospective study in a tertiary care teaching hospital

INTRODUCTION

Polypharmacy increases hazard of drug-drug interactions(DDIs), hospitalization, treatment toxicity, and mortality in elderly individuals with cancer. The present study explores and analyzes prevalence and severity of DDIs in geriatric cancer patients subjected to anticancer chemotherapy, their mechanisms, stratification of severity, and correlation between DDI risk and number of medications taken.

METHODS

This was a cross-sectional study conducted between January-July 2019 at the Medical Oncology/Hematology and Radiation-Oncology Departments, All India Institute of Medical Sciences(AIIMS) Rishikesh. The study included a convenience sampling of 126 geriatric cancer patients.

RESULTS

126 patients were enrolled in present study. DDIs were identified in 97.6% of elderly cancer patients, and 88.9% had at least one DDI with antineoplastic medications. Highest number of DDIs involving antineoplastic medications in any given patient was 12. DDIs involving medications used for treatment of non-cancerous diseases were observed in 83.3% of patients; highest number of interactions identified in any given patient was 15. Out of 473 interactions, 237(50.1%) DDIs were attributable to pharmacodynamic mechanisms of action. 126(27%) of DDIs involved pharmacokinetic mechanisms and 110(23.6%) involved unknown mechanisms. In this present study, total number of DDIs could be positively correlated with total number of medications and number of health problems.

CONCLUSIONS

Geriatric cancer patients are at high risk of DDIs ascribable to polypharmacy. Physicians may utilize online DDI checking softwares to alert themselves, characterize potential DDIs, and modify medications judiciously. An integrative and algorithmic approach with inclusion of geriatricians, oncologists, cardiologists, general practitioners, and clinical pharmacologists/ pharmacists is imperative to optimize drug therapy.

Drug-drug interactions in patients undergoing chemoradiotherapy and the impact of an expert team intervention

Background Several studies have examined the drug-drug interaction patterns in different patient populations and treatment settings; however, there is a need, particularly in the field of oncology and radiotherapy, for evaluating methods targeted towards preventing potential drug-drug interactions. One of the measures proposed is identifying potential interactions using computer programs and their evaluation by pharmacologists or clinical pharmacists, thereby providing clinically relevant information to the treating physician regarding the required prescription changes. Objective To determine the prevalence of potential drug-drug interactions in patients receiving chemoradiotherapy and assess the usefulness of expert team recommendations in minimizing interactions. Setting Patients admitted to the radiotherapy and oncology ward of a tertiary care teaching hospital in Karnataka, India. Method We conducted a prospective, cross-sectional study of prescriptions written for patients receiving chemoradiotherapy. Prescriptions containing two or more drugs, at least one of the drugs being an anticancer drug, were analyzed. They were screened for potential drug-drug interactions using the Lexicomp® drug interaction software. The interactions were classified as X, drug combination to be avoided; D, modification of therapy to be considered; and C, therapy to be monitored, as per the Lexicomp criteria. Main outcome measure The number of drug-drug interactions detected that were accepted by the treating radio-oncologist as requiring prescription change before and after the prescription review by an expert team. Results Two hundred twenty-three prescriptions were screened for the presence of drug-drug interactions; 106 prescriptions (47.53%) containing 620 drugs and 211 drug-drug interactions were identified. Of the 211 interactions identified, 6.64% (14/211), 18.48% (39/211), and 74.88% (158/211) drug-drug interactions belonged to category X, D, and C, respectively. Twenty-seven (50.94%) of the 53 category X and D interactions identified were accepted the oncologist as requiring a change in the prescription; an additional 13 (24.53%) interactions were identified as significant by the expert team, and 11 (84.62%) of these were accepted by the oncologist. Conclusion A system of alerting the treating physician to a potential drug-drug interaction leads to avoidance of prescription of the interacting drug combination, and the assistance by an expert team adds significantly to avoidance of clinically relevant drug interactions.

Polypharmacy, Inappropriate Medication Use, and Drug Interactions in Older Korean Patients with Cancer Receiving First-Line Palliative Chemotherapy

BACKGROUND

Polypharmacy is an important issue in the care of older patients with cancer, as it increases the risk of unfavorable outcomes. We estimated the prevalence of polypharmacy, potentially inappropriate medication (PIM) use, and drug-drug interactions (DDIs) in older patients with cancer in Korea and their associations with clinical outcomes.

SUBJECTS, MATERIALS, AND METHODS

This was a secondary analysis of a prospective observational study of geriatric patients with cancer undergoing first-line palliative chemotherapy. Eligible patients were older adults (≥70 years) with histologically diagnosed solid cancer who were candidates for first-line palliative chemotherapy. All patients enrolled in this study received a geriatric assessment (GA) at baseline. We reviewed the daily medications taken by patients at the time of GA before starting chemotherapy. PIMs were assessed according to the 2015 Beers criteria, and DDIs were assessed by a clinical pharmacist using Lexi-comp Drug Interactions. We evaluated the association between polypharmacy and clinical outcomes including treatment-related toxicity, and hospitalization using logistic regression and Cox regression analyses.

RESULTS

In total, 301 patients (median age 75 years; range, 70-93) were enrolled; the most common cancer types were colorectal cancer (28.9%) and lung cancer (24.6%). Mean number of daily medications was 4.7 (±3.1; range, 0-14). The prevalence of polypharmacy (≥5 medications) was 45.2% and that of excessive polypharmacy (≥10 medications) was 8.6%. PIM use was detected in 137 (45.5%) patients. Clinically significant DDIs were detected in 92 (30.6%) patients. Polypharmacy was significantly associated with hospitalization or emergency room (ER) visits (odds ratio: 1.73 [1.18-2.55], p < .01). Neither polypharmacy nor PIM use showed association with treatment-related toxicity.

CONCLUSION

Polypharmacy, PIM use, and potential major DDIs were prevalent in Korean geriatric patients with cancer. Polypharmacy was associated with a higher risk of hospitalization or ER visits during the chemotherapy period.

IMPLICATIONS FOR PRACTICE

This study, which included 301 older Korean patients with cancer, highlights the increased prevalence of polypharmacy in this population planning to receive palliative chemotherapy. The prevalence of polypharmacy and excessive polypharmacy was 45.2% and 8.6%, respectively. The prescription of potentially inappropriate medications (PIMs) was detected in 45.5% and clinically significant drug-drug interaction in 30.6% of patients. Given the association of polypharmacy with increased hospitalization or emergency room visits, this study points to the need for increased awareness and intervention to minimize polypharmacy in the geriatric cancer population undergoing chemotherapy. Moreover, specific criteria for establishing PIMs should be adopted for the treatment of older adults with cancer.

Prevalence of potential drug-drug interactions in outpatients on treatment with parenteral antineoplastic drugs

Background As live expectancy and cancer incidence growing, polypharmacy in oncology patients is also increasing, raising the risk of developing potential drug-drug interactions.Objective To assess the prevalence of clinically relevant potential drug-drug interactions among cancer patients who receive parenteral treatment at our outpatient clinic. Method Retrospective observational study which included randomly selected patients who had received parenteral treatment from November 1st 2016 to January 31st 2017. Interactions were checked in 3 databases, and classified as clinically relevant or not and in three categories of severity: contraindicated, consider modification or monitor. Results A total of 273 patients were included; of which seventy three (26.7%) had at least one clinically relevant potential drug-drug interaction. Amongst them, 54 (74%) had at least one classified as monitor treatment, 50 (68.5%) as contraindicated and 26 (35.6%) as consider modification. The number of chronic prescriptions was associated with a higher risk of drug interactions. Conclusion Around one in four patients on treatment with parenteral antineoplastic drugs presented a clinically relevant potential drug-drug interaction. A systematic assessment of drug-drug interactions should be implemented to reduce the risk of clinically relevant drug-drug interactions.

Interaction between phytotherapy and oral anticancer agents: prospective study and literature review

Cancer is becoming more prevalent in elderly patient. Due to polypharmacy, older adults with cancer are predisposed to drug-drug interactions. There is also an increasing interest in the use of complementary and alternative medicine (CAM). Thirty to seventy percent of patients with cancer have used CAM. Through pharmaceutical counseling sessions, we can provide advices on herb-drug interactions (HDI). All the patients seen in pharmaceutical counseling sessions were prospectively included. Information was collected during these sessions: prescribed medication (oral anticancer agents (OAA) and other drugs), CAM (phytotherapy especially), and use of over-the-counter (OTC) drugs. If pharmacist considered an interaction or an intervention clinically relevant, the oncologist was notified. Then, a literature review was realized to identify the potential HDI (no interactions, precautions for use, contraindication). Among 201 pharmacist counseling sessions, it resulted in 104 interventions related to 46 HDI, 28 drug-drug interactions and 30 others (wrong dosage, omission…). To determine HDI, we review 73 medicinal plants which are used by our patients with cancer and 31 OAA. A total of 1829 recommendations were formulated about 59 (75%) medical plants and their interaction with an OAA. Herb-drug interactions should not be ignored by healthcare providers in their management of cancer patients in daily practice.

Polypharmacy in elderly cancer patients: Challenges and the way clinical pharmacists can contribute in resource-limited settings

The aim of this study was to address the problems associated with polypharmacy in elderly cancer patients and to highlight the role of pharmacists in such cases in resource-limited settings. A narrative review of existing literature was performed to summarize the evidence regarding the impact of polypharmacy in elderly cancer patients and the pharmaceutical strategies to manage it. This review emphasizes the significance of polypharmacy, which is often ignored in real clinical practice. Polypharmacy in the elderly cancer population is mainly due to: chemotherapy with one or more neoplastic agents for cancer treatment, treatment for adverse drug reactions due to neoplastic agents, the patient's comorbid conditions, or drug interactions. The role of the clinical pharmacist in specialized oncology hospitals or oncology departments of tertiary care hospitals is well established; however, this is not the case in many developing countries. A clinical pharmacist can contribute to solving the problems associated with polypharmacy by identifying the risks associated with polypharmacy and its management in resource-limited settings. As in many developed countries, the involvement of a clinical pharmacist in cancer care for elderly patients may play a vital role in the recognition and management of polypharmacy-related problems. Further research can be conducted to support this role.

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Clinical pharmacology of oncology agents in older adults: A comprehensive review of how chronologic and functional age can influence treatment-related effects

Unique challenges exist when managing older adults with cancer. Associations between cancer and age-related physiologic changes have a direct impact on pharmacokinetics and pharmacodynamics of cancer therapies and can affect drug dosing, dose intensity, efficacy, safety and quality of life. The breadth and depth of these issues, however, have not been fully evaluated because the majority of clinical trials have focused on a younger and healthier population. As a consequence, little information is available to support clinicians in making evidence-based decisions regarding treatment with cancer therapies in older adults, especially those over age 75. Prior clinical pharmacology reviews summarized the literature on how age-related physiologic changes can influence and affect conventional and targeted anti-cancer treatments. Our article provides an updated review with expanded information that includes small molecule kinase inhibitors, monoclonal antibodies, immunotherapies, hormonal, conventional, and miscellaneous agents. Additionally, our article integrates how functional age, determined by the geriatric assessment (GA), can also influence treatment-related effects and health outcomes. Broadening cancer therapy trials to capture not only chronologic age but also functional age would allow clinicians to better identify subsets of older adults who benefit from treatment versus those most vulnerable to morbidity and/or mortality.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Drug Prescription Including Interactions with Anticancer Treatments in the Elderly: A Global Approach

BACKGROUND

Consequences of inappropriate prescriptions and polymedication in patients suffering from cancer are beginning to be well documented. However, the methods used to evaluate these consequences are often discussed. Few studies evaluate the risk of interaction with anticancer drugs in elderly patients suffering from cancer.

OBJECTIVES

To describe the prevalence (i) of polypharmacy, (ii) of potentially inappropriate drug prescriptions and (iii) of drug interactions involving anticancer treatments, using a multiple reference tools.

DESIGN

A retrospective, cross-sectional, multicenter study performed from January to December 2012.

PARTICIPANTS

Patients aged 65 years or older suffering from cancer presented at the oncogeriatric multidisciplinary meeting.

MEASUREMENTS

Polymedication (>6 drugs), potentially inappropriate prescriptions and drug interactions involving anticancer treatment were analyzed in combination with explicit and implicit criteria within a global approach.

RESULTS

Among the 106 patients included in this study, polypharmacy was present in 60.4% of cases, potentially inappropriate drug prescription in 63.1% and drug interactions in 16% of case, of which 47% involved anti-cancer treatments. Twenty-seven major drug interactions were identified and eight interactions involved chemotherapy.

CONCLUSION

Polymedication, inappropriate prescribing and drug interactions involving anti-cancer drugs are common and largely underestimated in elderly cancer patients.

The impact of comorbidity on cancer and its treatment

Answer questions and earn CME/CNE Comorbidity is common among cancer patients and, with an aging population, is becoming more so. Comorbidity potentially affects the development, stage at diagnosis, treatment, and outcomes of people with cancer. Despite the intimate relationship between comorbidity and cancer, there is limited consensus on how to record, interpret, or manage comorbidity in the context of cancer, with the result that patients who have comorbidity are less likely to receive treatment with curative intent. Evidence in this area is lacking because of the frequent exclusion of patients with comorbidity from randomized controlled trials. There is evidence that some patients with comorbidity have potentially curative treatment unnecessarily modified, compromising optimal care. Patients with comorbidity have poorer survival, poorer quality of life, and higher health care costs. Strategies to address these issues include improving the evidence base for patients with comorbidity, further development of clinical tools to assist decision making, improved integration and coordination of care, and skill development for clinicians. CA Cancer J Clin 2016;66:337-350. © 2016 American Cancer Society.

A pilot study on the impact of known drug-drug interactions in cancer patients

Background

When a patient concomitantly uses two or more drugs, a drug-drug interaction (DDI) can possibly occur, potentially leading to an increased or decreased clinical effect of a given treatment. Cancer patients are at high risk of such interactions because they commonly receive multiple medications. Moreover, most cancer patients are elderly and require additional medications for comorbidities. Aim of this preliminary observational study was to evaluate the incidence of well known and established DDIs in a cohort of cancer outpatients undergoing multiple treatments.

Methods

Anamnestic and clinical data were collected for 64 adult patients in the ambulatory setting with malignant solid tumors who were receiving systemic anticancer treatment.

Patients also declared all drugs prescribed by other specialists or self-taken in the previous 2 weeks. DDIs were divided into two different groups: ‘neoplastic DDIs’ (NDDIs), involving antitumoral drugs, and ‘not neoplastic DDIs’ (nDDIs), involving all other classes of drugs. The severity of DDIs was classified as major, moderate and minor, according to the ‘Institute for Pharmacological Research Mario Negri’ definition.

Results

About 34 % of cancer outpatients within our cohort were prescribed/assumed interacting drug combinations. The most frequent major NDDIs involved the anticoagulant warfarin (33 % of total NDDIs) that, in association with tamoxifen, or capecitabine and paclitaxel, increased the risk of haemorrhage. About 60 % of nDDIs involved acetylsalicylic acid.

Conclusions

Overall, 16 % of DDIs were related to an A-level strength of recommendation to be avoided. The lack of effective communication among specialists and patients might have a role in determining therapeutic errors. Our pilot study, although limited by a small cohort size, highlights the urgent need of implementing the clinical management of cancer outpatients with new strategies to prevent or minimize potential harmful DDIs.

Inappropriate prescribing in patients accessing specialist palliative day care services

BACKGROUND

For patients accessing specialist palliative care day services, medication is prescribed routinely to manage acute symptoms, treat long-term conditions or prevent adverse events associated with these conditions. As such, the pharmacotherapeutic burden for these patients is high and polypharmacy is common. Consequently, the risk of these patients developing drug-related toxicities through drug–drug interactions is exacerbated. Medication use in this group should, therefore, be evaluated regularly to align with achievable therapeutic outcomes considering remaining life expectancy.

OBJECTIVE

To (1) assess the prevalence of inappropriate medication use; (2) identify potential drug–drug interactions; and, (3) determine how many potential drug– drug interactions could be prevented by discontinuing inappropriate medication.

SETTING

A specialist tertiary care palliative care centre in Northern England serving a population of 330,000.

MAIN OUTCOME MEASURE

Prescribing of inappropriate medication.

METHOD

Medication histories for patients accessing a specialist palliative day care centre were established and a modified Delphi method was used to reach consensus of medication appropriateness. The Delphi method utilized a framework considering the following factors: remaining life expectancy of the patient, time until benefit of the treatment, goals of care and treatment targets. Potential drug interactions were established using drug interaction recognition software and categorised by their ability to cause harm.

RESULTS

A total number of 132 patients were assessed during the study period who were prescribed 1,532 (mean = 12/patient) medications; 238 (16 %) were considered inappropriate in the context of limited life expectancy. The most common class of medications considered inappropriate were the statins, observed in 35 (27 %) patients. A total of 267 potential drug–drug interactions were identified; 112 were clinically significant and 155 were not considered clinically significant. Discontinuation of inappropriate medication would reduce the total number of medications taken to 1,294 (mean = 10/patient) and prevent 31 clinically significant potential drug–drug interactions.

CONCLUSION

Patients accessing specialist palliative day care services take many inappropriate medications. These medications not only increase the pharmacotherapeutic burden for the patient but they also contribute to potential drug–drug interactions. These patients should have their medication reviewed in the context of life limiting illness aligned with achievable therapeutic outcomes.

Polypharmacy in patients with advanced cancer and pain: a European cross-sectional study of 2282 patients

CONTEXT

Patients with advanced cancer need multiple drugs to control symptoms and to treat cancer and concomitant diseases. At the same time, the goal of treatment changes as life expectancy becomes limited. This results in a risk for polypharmacy, maintained use of unneeded drugs, and drug-drug interactions (DDIs).

OBJECTIVES

The aim of the study was to analyze the use of medications and to identify unneeded drugs, and drugs and drug combinations with a risk for DDIs in a cohort of advanced cancer pain patients, defined by a need for a World Health Organization analgesic ladder Step III opioid.

METHODS

All drugs taken within a study day by cancer patients receiving opioids for moderate or severe pain (Step III opioids) were analyzed. Nonopioids and adjuvants were analyzed for their use across countries. Unneeded medications and drugs and drug combinations with a risk for pharmacodynamic and pharmacokinetic DDIs were identified on the basis of published literature and electronic resources.

RESULTS

In total, 2282 patients from 17 centers in 11 European countries were included. They received a mean of 7.8 drugs (range 1-20). Over one-quarter used 10 or more medications. The drugs and drug classes most frequently coadministered with opioids were proton pump inhibitors, laxatives, corticosteroids, paracetamol (acetaminophen), nonsteroidal anti-inflammatory drugs, metoclopramide, benzodiazepines, anticoagulants, antibiotics, anticonvulsants, diuretics, and antidepressants. The use of nonopioids and essential adjuvants varied across countries. Approximately 45% of patients received unnecessary or potentially unnecessary drugs, and about 7% were given duplicate or antagonizing agents. Exposures to DDIs were frequent and increased the risk of sedation, gastric ulcerations, bleedings, and neuropsychiatric and cardiac complications. Many patients were exposed to pharmacokinetic DDIs involving cytochrome P450, including about 58% who used a Step III opioid CYP3A4 (izoenzyme of cytochrome P450) substrate, and more than 10% who were given major CYP3A4 inhibitors or inducers.

CONCLUSION

Patients with cancer treated with a World Health Organization Step III opioid use a high number of drugs. Nonopioid analgesics and corticosteroids are frequently used, but different patterns of use between countries were found. Many patients receive unneeded drugs and are at risk of serious DDIs. These findings demonstrate that drug therapy in these patients needs to be evaluated continuously.

Twelve-month frequency of drug-metabolizing enzyme and transporter-based drug-drug interaction potential in patients receiving oral enzyme-targeted kinase inhibitor antineoplastic agents

OBJECTIVE

To describe 12-month rates and patterns of coprescription of drugs that potentially create drug-drug interactions (DDIs) through shared metabolic or transport pathways for 9 enzyme-targeted kinase inhibitor oral antineoplastic drugs (OADs).

PATIENTS AND METHODS

We used a deidentified pharmacy claims database identifying patients prescribed dasatinib, erlotinib, everolimus, imatinib, lapatinib, nilotinib, pazopanib, sorafenib, or sunitinib between January 1, 2008, and May 31, 2010. Coprescribing was 1 or more overlapping days of supply between the OAD and potential DDI drugs during the 12-month period beginning on the OAD index date. Product labels identified the cytochrome P450 metabolic enzymes used and whether P-glycoprotein was used by the OADs. Drugs that induce and/or inhibit these pathways were identified from the label and online resources.

RESULTS

Sample sizes ranged from 96 (pazopanib group) to 4617 (imatinib group). Coprescribing rates with drugs that may decrease OAD effectiveness were 359/1546 (23%) (sunitinib group) to 1851/3263 (57%) (erlotinib group). Coprescribing rates with drugs that may increase OAD toxicity were 364/1546 (24%) (sunitinib group) to 71/96 (74%) (pazopanib group). Patients coprescribed DDI drugs had a median of 1 to 4 more medications present on the OAD index date than those not coprescribed a DDI drug. Most groups coprescribed DDI drugs had a median of 180 or more OAD days of supply during follow-up. The proportion of OAD days of supply with overlapping days of DDI drugs ranged from 7% to 85%. Generally, oncologists prescribed the OAD and nononcologists the DDI drug.

CONCLUSION

Coprescription of drugs that induce or inhibit metabolic pathways used by enzyme-targeted kinase inhibitor OADs is high. The clinical consequences need further study.

Polypharmacy in elderly patients with cancer: clinical implications and management

More and more elderly people with cancer are treated in oncology clinics worldwide every year, many of whom have comorbid disorders treated with one or more drugs. Moreover, these patients might also take self-prescribed over-the-counter drugs or complementary and alternative medicines, which they might not tell their doctor about. Initiation of chemotherapy with one or more cytotoxic or targeted agents and drugs for treatment of cancer symptoms or toxic effects related to treatment can result in polypharmacy. We examine the clinical implications of polypharmacy. Challenges for the medical teams who treat elderly patients with cancer include identification of what drugs are actually being taken by the patient, avoidance or management of any adverse effects or drug interactions, and reassessing the patient's overall treatment. We address these issues and propose practical recommendations for management of treatment for elderly patients with cancer.

A novel method using confocal laser scanning microscopy for sensitive measurement of P-glycoprotein-mediated transport activity in Caco-2 cells

OBJECTIVES

The aim of this study was to use time-lapse confocal laser scanning microscopy to establish a more sensitive and specific method for evaluating P-glycoprotein activity in Caco-2 cells.

METHODS

The change in the fluorescence of residual rhodamine 123 at the apical and central regions of Caco-2 cells was measured in the presence of digoxin or St John's wort by using time-lapse confocal laser scanning microscopy. The data were compared with measurements made using conventional techniques, a fluorescence microplate reader and a fluorescence microscope.

KEY FINDINGS

The percentage decrease of rhodamine 123 caused by 10 µm digoxin or 0.1 µg/ml St John's wort was significantly larger in the apical region of the Caco-2 cell than in the central region or in the whole cell. The digoxin-induced inhibition in the apical region as measured by time-lapse confocal laser scanning microscopy was greater than that measured in the whole cell by a microplate reader or a fluorescence microscope.

CONCLUSIONS

The assay of residual rhodamine 123 in the apical region of Caco-2 cells by confocal laser scanning microscopy was more sensitive than the conventional methods using a microplate reader or fluorescence microscopy. It will be a valuable screening tool for studying both the inhibition and induction of P-glycoprotein activity.