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Objective: Chromium treatment has been reported to improve glycemic control and insulin sensitivity in specific populations of patients with type 2 diabetes. The aim of this study was to determine the effect of chromium treatment on glycemic control in a Western population of insulin-dependent patients with type 2 diabetes.Research Design and Methods: In this 6-month double-blind study, patients with an HbA(1c) (A1C) >8% and insulin requirements of >50 units/day were randomly assigned to receive treatment with placebo or 500 or 1,000 mug chromium daily in the form of chromium picolinate. The primary efficacy parameter was a change in A1C. Secondary end points were changes in lipid profile, BMI, blood pressure, and insulin requirements.Results: In this per-protocol analysis (n = 46), the decrease in A1C was approximately equal across the three groups (0.4%). All patients had a BMI >25 kg/m(2). No differences were found in the secondary end points. We found a weak relationship between an increasing serum chromium concentration and improvement of the lipid profile.Conclusions: There is no evidence that high-dose chromium treatment is effective in obese Western patients with type 2 diabetes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Capecitabine is an oral prodrug of 5-fluorouracil and has been studied for the treatment of colorectal cancer. In 2 Phase III trials, capecitabine was at least as effective as 5-fluorouracil plus leucovorin and had a more favorable toxicity profile. OBJECTIVE: A cost-benefit analysis was used to assess the pharmacoeconomic profile of capecitabine compared with 5-fluorouracil/leucovorin, given according to the Mayo regimen, for colorectal cancer patients treated in the Netherlands. METHODS: The medical files of patients treated for colorectal cancer at a single center from 1999 to 2002 were examined to determine the numbers of outpatient visits for 5-fluorouracil/leucovorin administration, health care use and medication to manage adverse effects, and travel distance to and from the hospital. The costs of capecitabine treatment were simulated by assuming that the same patients were treated with capecitabine instead of 5-fluorouracil/leucovorin. Toxicity data for capecitabine were derived from 2 Phase III studies that compared capecitabine and 5-fluorouracil/leucovorin. RESULTS: The files of 65 patients were reviewed. Thirty-two patients received adjuvant treatment and 33 patients were treated palliatively for metastatic disease. The mean total costs of palliative treatment were Euro 4004 with capecitabine and Euro 5614 with 5-fluorouracil/leucovorin. These results were robust in sensitivity analyses. The cost savings were primarily related to the number of outpatient visits for capecitabine versus the number of day-care treatment days for 5-fluorouracil/leucovorin, despite the higher acquisition costs of capecitabine. CONCLUSIONS: Based on this analysis, treatment of colorectal cancer with oral capecitabine is cost saving in the Netherlands compared with 5-fluorouracil plus leucovorin administered according to the Mayo regimen. Baseline savings were estimated at Euro 1610 for palliative treatment and Euro 934 for adjuvant treatment. [ABSTRACT FROM AUTHOR]

A sensitive and reliable LC-MS/MS method was developed and validated for the quantification of oxycodone and metabolites in human plasma. The method has a runtime of 6 min and a sensitivity of 0.1 μg/L for all analytes. Sample preparation consisted of protein precipitation. Separation was performed on a Kinetix biphenyl column (2.1 × 100 mm, 1.7 μm), using ammonium formate 5 mm in 0.1% aqueous formic acid and methanol LC-MS grade 100% in gradient elution at a flow rate of 0.4 ml/min. Detection was performed in multiple reaction monitoring mode using positive electrospray ionization. The method was linear over the calibration range of 0.1-25.0 μg/L for oxycodone, noroxycodone and noroxymorphone and 0.1-5.0 μg/L for oxymorphone. The method demonstrated good performance in terms of intra- and interday accuracy (86.5-110.3%) and precision (CV 1.7-9.3%). The criteria for the matrix effect were met (CV < 15%) except for noroxymorphone, for which an additional method was applied to compensate for the matrix effect. Whole blood samples were stable for 4 h at room temperature. Plasma samples were stable for 24 h at room temperature and 3 months at -20°C. Furthermore, the method was successfully applied in a pharmacokinetic drug interaction study of oxycodone and enzalutamide in patients with prostate cancer., (© 2024 The Authors. Biomedical Chromatography published by John Wiley & Sons Ltd.)

Aim: Oxycodone is known to have numerous drug-drug interactions (DDIs) that can potentially decrease efficacy or lead to adverse drug reactions (ADRs). However, there is limited research on the frequency of DDIs associated with oxycodone, which is important in optimising pharmacovigilance and the need for additional research on certain DDIs. In this study, the frequency of pharmacologically and clinically relevant DDI perpetrators was studied in patients with cancer., Methods: This was a cross-sectional study using hospital pharmacy records of patients with cancer who were prescribed oxycodone between September 2021 and September 2022. Medication records of patients prescribed oxycodone during a period of ≥ 5 consecutive days (= oxycodone treatment episodes) were reviewed to identify the concomitant use of pharmacologically relevant perpetrators, based on reference sources (Lexicomp®, Micromedex®, the Dutch Kennisbank and the Dutch Commentaren Medicatiebewaking). The clinical relevance was examined by a clinical pharmacologist and a medical oncologist. Additionally, the frequency of double interactions-concomitant oxycodone use with two CYP3A4 and / or CYP2D6 perpetrators-was studied., Results: Overall, 254 oxycodone treatment episodes were included, of which 227 (89.4%) were found to contain at least one pharmacologically relevant DDI perpetrator. Of these, 210 (82.7%) were considered to be clinically relevant. A total of 80 different pharmacologically relevant perpetrators were identified, with 65 (81.3%) being considered clinically relevant. Double interactions were observed in 21 (8.3%) oxycodone treatment episodes., Conclusion: A high frequency of pharmacologically and clinically relevant perpetrators of oxycodone was observed in our cohort. Moreover, a high number of double interactions involving oxycodone was registered. More intense monitoring of DDIs may be needed to improve medication safety of patients with cancer taking oxycodone., (© 2024. The Author(s).)

Background and Objective: Up to 90% of patients with castration-resistant prostate cancer (CRPC) will develop symptomatic bone metastases requiring pain medication, with opioids being the mainstay of therapy in treating moderate and severe pain. Enzalutamide is an androgen receptor antagonist for the treatment of CRPC and a strong inducer of cytochrome P450 (CYP)3A4. Hereby, enzalutamide potentially reduces the exposure of oxycodone, an opioid metabolized by CYP3A4 and CYP2D6. Our objective was to evaluate the potential drug-drug interaction of enzalutamide and oxycodone., Methods: A prospective, nonrandomized, open-label, two-arm parallel study was performed. All patients received a single dose of 15 mg normal-release oxycodone. Patients in the enzalutamide arm (ENZ-arm) received enzalutamide 160 mg once daily. Plasma concentrations of oxycodone and its metabolites were quantified using a validated liquid chromatography with tandem mass spectrometry (LC-MS/MS) method., Results: Twenty-six patients (13 ENZ-arm; 13 control arm) were enrolled in the study. Enzalutamide decreased the mean AUC 0-8 h and C max of oxycodone with, respectively, 44.7% (p < 0.001) and 35.5% (p = 0.004) compared with the control arm. The AUC 0-8 h and C max of the active metabolite oxymorphone were 74.2% (p < 0.001) and 56.0% (p = 0.001) lower in the ENZ-arm compared with the control arm. In contrast, AUC 0-8 h and C max of the inactive metabolites noroxycodone and noroxymorphone were significantly increased by enzalutamide., Conclusion: Co-administration of enzalutamide significantly reduced exposure to oxycodone and its active metabolite oxymorphone in men with prostate cancer. This should be taken into account when prescribing enzalutamide combined with oxycodone., (© 2023. The Author(s).)

Background: Expensive novel anticancer drugs put a serious strain on healthcare budgets, and the associated drug expenses limit access to life-saving treatments worldwide., Objective: We aimed to develop alternative dosing regimens to reduce drug expenses., Methods: We developed alternative dosing regimens for the following monoclonal antibodies used for the treatment of lung cancer: amivantamab, atezolizumab, bevacizumab, durvalumab, ipilimumab, nivolumab, pembrolizumab, and ramucirumab; and for the antibody-drug conjugate trastuzumab deruxtecan. The alternative dosing regimens were developed by means of modeling and simulation based on the population pharmacokinetic models developed by the license holders. They were based on weight bands and the administration of complete vials to limit drug wastage. The resulting dosing regimens were developed to comply with criteria used by regulatory authorities for in silico dose development., Results: We found that alternative dosing regimens could result in cost savings that range from 11 to 28%, and lead to equivalent pharmacokinetic exposure with no relevant increases in variability in exposure., Conclusions: Dosing regimens based on weight bands and the use of complete vials to reduce drug wastage result in less expenses while maintaining equivalent exposure. The level of evidence of our proposal is the same as accepted by regulatory authorities for the approval of alternative dosing regimens of other monoclonal antibodies in oncology. The proposed alternative dosing regimens can, therefore, be directly implemented in clinical practice., (© 2023. The Author(s).)

Purpose: Peripheral neuropathy (PN) is common in multiple myeloma (MM) patients. More insight has been gained concerning the role of vitamin D in preventing PN. However, studies evaluating the effects of vitamin D 3 supplementation on PN are lacking. The aims of this study are to (1) evaluate the effectiveness of a vitamin D 3 regimen on achieving adequate vitamin D levels in deficient MM patients and to (2) exploratively evaluate the effect of vitamin D 3 supplementation on PN., Methods: Thirty-nine MM patients with inadequate (< 75 nmol/L [= 30 ng/mL]) 25-hydroxyvitamin D (25(OH)D) levels were included in this multicenter, prospective, single-arm study, of whom 35 patients completed the study. They received oral vitamin D 3 for 6 months according to a dose escalation regimen that consisted of one or two loading doses of 200,000 international units (IU), and maintenance doses of 800, 1600, or 3200 IU/day depending on the 25(OH)D level. A validated questionnaire was used to measure PN., Results: Median 25(OH)D increased from 38 (IQR 32-52) nmol/L at baseline to 77 (IQR 72-87) nmol/L after 6 months (P < 0.001). Adequate 25(OH)D levels were achieved by 66% of the subjects, and 34% were within the range of 50-75 nmol/L. Furthermore, in 37% of the participants, PN severity decreased (P = 0.007)., Conclusion: The use of substantially higher vitamin D 3 doses than recommended in current guidelines resulted in a significant increase in vitamin D levels in MM patients. Furthermore, evaluation of PN showed a significant decrease in PN grading. However, this exploratory evaluation needs further confirmatory research., (© 2023. The Author(s).)

Aim: This study examined whether anthropometric and body composition parameters such as body surface area (BSA), lean body mass (LBM), and total body weight (TBW) are correlated with docetaxel clearance and exposure by analyzing area under the curve. In addition, LBM, TBW, and a fixed dose were compared with BSA as dosing parameters for dose individualization of docetaxel., Methods: Thirty-six patients receiving docetaxel chemotherapy for breast or metastatic castration-resistant prostate carcinoma were included. Before treatment, LBM was measured using a dual-energy X-ray absorptiometry scanner. Blood samples were collected up to 180 minutes after dosing to analyze docetaxel concentrations and determine individual pharmacokinetic parameters., Results: No significant correlations were found between docetaxel clearance and the anthropometric and body composition variables (BSA, LBM, and TBW). The area under the curve was significantly but poorly correlated with BSA [r = 0.452 ( P = 0.016)] and TBW [r = 0.476 ( P = 0.011)]. The mean absolute percentage error and mean error of simulated dosing based on LBM and fixed dosing were not significantly different from those of BSA. For TBW, only mean absolute percentage error was significantly higher compared with dosing based on BSA (24.1 versus 17.1, P = 0.001)., Conclusions: There was no clinically relevant correlation between docetaxel pharmacokinetics and the anthropometric and body composition variables BSA, LBM, and TBW. Therefore, dose individualization of docetaxel based on LBM, TBW, or fixed dosing cannot be recommended over BSA-based dosing., Competing Interests: The authors declare no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: National health technology assessments (HTAs) across Europe show differences in evidentiary requirements from assessments by the European Medicines Agency (EMA), affecting time to patient access for drugs after marketing authorization. This article analyzes the differences between EMA and HTA bodies' evidentiary requirements for oncology drugs and provides recommendations on potential further alignment to minimize and optimally manage the remaining differences., Methods: Interviews were performed with representatives and drug assessment experts from EMA and HTA bodies to identify evidentiary requirements for several subdomains and collect recommendations for potentially more efficiently addressing differences. A comparative analysis of acceptability of the evidence by EMA and the HTA bodies and for potential further alignment between both authorities was conducted., Results: Acceptability of available evidence was higher for EMA than HTA bodies. HTA bodies and EMA were aligned on evidentiary requirements in most cases. The subdomains showing notable differences concerned the acceptance of limitation of the target population and extrapolation of target populations, progression-free survival and (other) surrogate endpoints as outcomes, cross-over designs, short trial duration, and clinical relevance of the effect size. Recommendations for reducing or optimally managing differences included joint early dialogues, joint relative effectiveness assessments, and the use of managed entry agreements., Conclusions: Differences between assessments of EMA and HTA bodies were identified in important areas of evidentiary requirements. Increased alignment between EMA and HTA bodies is suggested and recommendations for realization are discussed., (Copyright © 2022. Published by Elsevier Inc.)

Purpose: Polystyrene sulfonate is used for binding potassium in patients with chronic kidney disease (CKD). Because of its binding properties, it can potentially bind other medications and thereby decrease their bioavailability and effectiveness. Amitriptyline, often used by CKD patients for neuropathic pain, shows significant binding to polystyrene sulfonate in vitro. The purpose of this study was to determine the effect of polystyrene sulfonate on the exposure of amitriptyline in vivo when taken concomitantly in healthy volunteers., Methods: We performed a prospective cross-over study in nine healthy volunteers. Participants were 18 years of age or older, did not use any medication, and had no known allergy to amitriptyline or polystyrene sulfonate. Participants visited Deventer Teaching Hospital twice. Once they received a single dose of amitriptyline 50 mg and once they received a single dose of both polystyrene sulfonate 15 g and amitriptyline 50 mg taken concomitantly, with a wash out period of at least 1 week. After intake of the medication, six blood samples were collected, at 2, 3, 4, 5, 6, and 8 h. Blood samples were analysed to determine maximum concentration (Cmax) and area under the curve 0-8 h after intake (AUC 0-8 h ). Difference in Cmax and AUC 0-8 h was analysed with a paired T-test or Wilcoxon signed rank test, depending on normality of the data. A p-value < 0.05 was considered statistically significant., Results: Of the nine participants included, eight participants completed both visits to the hospital. Mean maximum concentration (Cmax) of amitriptyline was 35.61 µg l -1 (95% CI 27.90-43.33 µg l -1 ) when taken alone, compared to 9.25 µg l -1 (95% CI 6.59-11.92 µg l -1 ) when taken with polystyrene sulfonate (p < 0.001). Mean AUC 0-8 h of amitriptyline was 168.20 µg × h l -1 (95% CI 139.95-196.45 µg × h l -1 ) when taken alone and 45.78 µg × h l -1 (95% CI 30.20-61.36 µg × h l -1 ) when taken with polystyrene sulfonate (p < 0.0001)., Conclusion: These results show a significant decrease in exposure of amitriptyline of approximately 75% when taken concomitantly with polystyrene sulfonate, thereby probably compromising therapy efficacy. Patients using both amitriptyline and polystyrene sulfonate should be informed to separate intake of these medications., Trial Registration: NL8539 (17 April 2020)., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Small-molecule kinase inhibitors (SMKIs) represent the cornerstone in the treatment of non-small cell lung cancer (NSCLC) patients harboring genetic driver mutations. Because of the introduction of SMKIs in the last decades, treatment outcomes have drastically improved. Their treatment efficacy, the development of drug resistance as well as untoward toxicity, all suffer from large patient variability. This variability can be explained, at least in part, by their oral route of administration, which leads to a large inter- and intra-patient variation in bioavailability based on differences in absorption. Additionally, drug-drug and food-drug interactions are frequently reported. These interactions could modulate SMKI efficacy and/or untoward toxicity. Furthermore, the large patient variability could be explained by the presence of germline variations in target receptor domains, metabolizing enzymes, and drug efflux transporters. Knowledge about these predictor variations is crucial for handling SMKIs in clinical practice, and for selecting the most optimal therapy. In the current review, the literature search included all SMKIs registered for locally-advanced and metastatic NSCLC by the US Food and Drug Administration (FDA) or European Medicines Agency (EMA) until March 24th, 2022. The BIM deletion showed a significantly decreased PFS and OS for East-Asian patients treated with gefitinib, and has the potential to be clinically relevant for other SMKIs as well. Furthermore, we expect most relevance from the ABCG2 34 G>A and CYP1A1 variations during erlotinib and gefitinib treatment. Pre-emptive CYP2D6 testing before starting gefitinib treatment can also be considered to prevent severe drug-related toxicity. These and other germline variations are summarized and discussed, in order to provide clear recommendations for clinical practice., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background Sevelamer and polystyrene sulfonate are used for treating hyperphosphatemia and hyperkalaemia in chronic kidney disease patients. Because of their binding properties, these resins potentially bind other drugs in the gastrointestinal tract, thereby decreasing their bioavailability and clinical effectiveness. Aim The aim of this study was to explore co-dispensed drug use in patients on sevelamer or polystyrene sulfonate to identify potential novel binding interactions. Method In this in silico study, the 100 drugs most frequently co-dispensed with sevelamer/polystyrene sulfonate in the period 2000-2018 were extracted from the University Groningen IADB.nl database. Drugs dispensed to < 5% of patients, drugs not orally administered, drugs administered once daily before bedtime and drugs for which information on binding interactions with sevelamer or polystyrene was already available were excluded. The likelihood of an interaction (yes or no) of the included drugs was assessed based on pKa- and Log P values. For sevelamer, drugs with a pKa (acid) between 1.5 and 7.4 and or a Log P value > 2.0 were identified as potential interacting drug. For polystyrene sulfonate, drugs with a pKa (base) > 1.5 were identified as potential interacting drug. Results Of the top 100 drugs most frequently co-dispensed with sevelamer/polystyrene sulfonate, 22 and 27 potentially clinically relevant new interacting drugs were identified for sevelamer and polystyrene sulfonate respectively. Conclusion Several potentially relevant novel binding interactions for sevelamer and polystyrene sulfonate were identified based on dispensing data and assessment of chemical properties for which further interaction research is warranted., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Drug-drug interactions (DDIs) with anticancer drugs are common and can significantly affect efficacy and toxicity of treatment. Therefore, a Dutch Multidisciplinary Expert group is assessing the clinical significance of DDIs in oncology and provides recommendations for the management of these DDIs. We present an overview of methodology and outcome of an evidence- and consensus-based assessment of DDIs between anticancer drugs and non-anticancer drugs. A literature search was performed through PubMed and EMA and FDA assessment reports, to identify potential DDI's involving anticancer drugs. For each potential DDI a concept report for risk analysis and practical advice for management was created. Subsequently, this risk analysis and the corresponding advice were assessed and weighed. A total of 290 potential DDIs have been identified in the literature thus far. Of these 290 potential DDIs, the Expert Group has identified 94 (32%) DDIs as clinically relevant, with a need for an automated alert and a suggested intervention. Furthermore, 110 DDIs have been identified as clinically not relevant. For 86 potential DDIs evidence supporting a relevant DDI was insufficient and in these cases neither an alert nor advice regarding a suggested intervention were formulated. A transparent risk analysis is presented for identification of clinically relevant DDIs with anticancer drugs. Integration of DDI guidelines into the national electronic prescribing system is essential to achieve optimal efficacy and minimal toxicity in patients receiving anticancer therapy. A clear overview of clinically relevant DDIs with anticancer therapy provides clinicians with a structured, evidence-based and consensus-built tool for anticancer therapy surveillance., Competing Interests: Conflict of interest RvL: Research (unrestricted) grants Roche, Bayer, Pfizer, Boehringer Ingelheim, Astellas, BMS. Consultancy: MSD, BMS, Sanofi, Astellas, Pfizer, Roche Travel grants: Roche, Novartis, Pfizer, Astellas NS: provided consultation or attended advisory boards for AIMM Therapeutics, Boehringer Ingelheim, Ellipses Pharma. N Steeghs received research grants for the institute from AB Science, Abbvie, Actuate Therapeutics, Amgen, Array, AstraZeneca/MedImmune, Bayer, Blueprint Medicines, Boehringer Ingelheim, Bristol-Myers Squibb, Cantargia, Cytovation, Deciphera, Genentech/Roche, GlaxoSmithKline, Incyte, InteRNA, Lilly, Merck Sharp & Dohme, Merus, Novartis, Pfizer, Pierre Fabre, Roche, Sanofi, Taiho, Takeda (outside the submitted work) TvG: In the last 3 years TvG has received lecture fees and study grants from Chiesi and Astellas, in addition to consulting fees from Roche Diagnostics, Vitaeris, CSL Behring, Astellas, Aurinia Pharma and Novartis. In all cases money has been transferred to hospital accounts, and none has been paid to his personal bank accounts.  TvG does not have employment or stock ownership at any of these companies, and neither does he have patents or patent applications MlC, AR, AvdT, BvV, WK, BW, OV, and FJ report no conflict of interest or funding information, (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: COBRA was developed as a decision rule to predict which patients visiting the emergency department (ED) following intentional drug overdose will not require intensive care unit (ICU) interventions. COBRA uses parameters from five vital systems (cardiac conduction, oxygenation, blood pressure, respiration, and awareness) that are readily available in the ED. COBRA recommends against ICU admission when all these parameters are normal., Objective: The primary aim of this study was to determine the negative predictive value (NPV) of COBRA in predicting ICU interventions. Secondary outcomes were the sensitivity, specificity and positive predictive value (PPV), and the observation time required for a reliable prediction., Design: Observational cohort study., Settings and Participants: Patients with a reported intentional overdose with drugs having potential acute effects on neurological, circulatory or ventilatory function were included, and data necessary to complete the decision rule was collected. The attending physician in the ED made the actual admission decision, on the basis of clinical judgement. COBRA was measured 0, 3 and 6 h after arrival at the ED., Outcome Measures: Need for ICU interventions (treatment of convulsion; defibrillation; mechanical or noninvasive ventilation; intravenous administration of vasopressive agents, antiarrhythmics, atropine, calcium, magnesium or sedation; continuous hemofiltration or administration of antagonist/antidote and fluid resuscitation)., Main Results: Of 230 new cases (144 unique patients), 59 were immediately referred to the psychiatric services and/or sent home by the attending physician, 27 went to a regular ward, and 144 were admitted to the ICU. Of these 144 cases, 40 required one or more ICU interventions. By the time the first parameters were collected, the NPV of COBRA was 95.6%. After 3 h of observation, NPV was 100%, while sensitivity, specificity and PPV were 100, 61.1 and 35.1%, respectively. None of these values improved by prolonging the observation time to 6 h., Conclusion: In patients with a reported intentional overdose with drugs having potential acute effects on neurological, circulatory or ventilatory function, the COBRA decision rule showed good performances in predicting the need for intensive care interventions, with a NPV of 100% after 3 h of observation., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Cabozantinib is registered in fixed 60 mg dose. However, 46% to 62% of patients in the registration studies needed a dose reduction due to toxicity. Improved clinical efficacy has been observed in renal cell carcinoma patients (RCC) with a cabozantinib exposure greater than 750 μg/L. In our study we explored the cabozantinib exposure in patients with different tumour types. We included RCC patients from routine care and salivary gland carcinoma (SGC) patients from a phase II study with ≥1 measured C min at steady-state. The geometric mean (GM) C min at the starting dose, at 40 mg and at best tolerated dose (BTD) were compared between both tumour types. Forty-seven patients were included. All SGC patients (n = 22) started with 60 mg, while 52% of RCC patients started with 40 mg. GM C min at the start dose was 1456 μg/L (95% CI: 1185-1789) vs 682 μg/L (95% CI: 572-812) (P < .001) for SGC and RCC patients, respectively. When dose-normalised to 40 mg, SGC patients had a significantly higher cabozantinib exposure compared to RCC patients (C min 971 μg/L [95% CI: 790-1193] vs 669 μg/L [95% CI: 568-788]) (P = .005). Dose reductions due to toxicity were needed in 91% and 60% of SGC and RCC patients, respectively. Median BTD was between 20 to 30 mg for SGC and 40 mg for RCC patients. GM C min at BTD were comparable between the SGC and the RCC group, 694 μg/L (95% CI: 584-824) vs 583 μg/L (95% CI: 496-671) (P = .1). The observed cabozantinib exposure at BTD of approximately 600 μg/L is below the previously proposed target. Surprisingly, a comparable exposure at BTD was reached at different dosages of cabozantinib for SGC patients compared to RCC patients Further research is warranted to identify the optimal exposure and starting dose to balance efficacy and toxicity., (© 2021 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Purpose: Peripheral neuropathy (PN) is common in patients with multiple myeloma (MM). We hypothesized that the relationship between hypovitaminosis D and PN described in diabetes mellitus patients may also be present in MM patients., Methods: To study this potential association, we assessed the incidence of hypovitaminosis D (vitamin D < 75 nmol/L [= 30 ng/mL]) in smouldering and active MM patients in two Dutch hospitals. Furthermore, a validated questionnaire was used to distinguish different PN grades., Results: Of the 120 patients included between January 2017 and August 2018, 84% had an inadequate vitamin D level (median vitamin D level 49.5 nmol/L [IQR 34-65 nmol/L]; mean age: 68 years [SD ± 7.7]; males: 58%). PN was reported by 69% of patients (n = 83); however, of these 83 patients, PN was not documented in the medical records of 52%. An association was found between lower vitamin D levels and higher incidence of PN in the total population (P = 0.035), and in the active MM patients (P = 0.016)., Conclusion: This multi-centre cohort study showed that PN and hypovitaminosis D are common in MM patients, and addressing low vitamin D levels in the treatment of MM patients might be beneficial in reducing the risk of PN. More attention for PN is warranted, as PN is underreported by clinicians. Further research is needed to fully understand the implications of vitamin D in the development of PN in patients with MM., Clinical Trial Registration: Netherland Trial Register NL5835, date of registration July 28, 2016., (© 2021. The Author(s).)

This study explored the binding of 28 drugs, which were selected based on frequency of concomitant use and chemical properties, to sevelamer and polystyrene sulfonate in vitro. The relative binding was determined by dissolving the investigated drugs alone (=control), together with 800 mg of sevelamer and 15 g of polystyrene sulfonate at different pH levels (1.5, 5.5, and 7.4), respectively. After incubation at 37℃ and shaking for 60 min, the solutions were diluted and centrifuged, and the drug concentrations were quantified with validated analytical assays. The binding assays were performed in threefold. The mean relative binding (MRB) at each pH level was calculated, with a MRB >20% for at least one pH level to be considered as relevant binding. Fourteen and 23 potentially new binding interactions were identified with sevelamer and polystyrene sulfonate, respectively. These potentially new binding interactions have to be studied in vivo to assess their clinical relevance., (© 2021 The Authors. Pharmacology Research & Perspectives published by British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics and John Wiley & Sons Ltd.)

Co-treatment with gastric acid suppressants (GAS) in patients taking anticancer drugs that exhibit pH-dependant absorption may lead to decreased drug exposure and may hamper drug efficacy. In our study, we investigated whether a 1-hour time interval between subsequent intake of pazopanib and GAS could mitigate this negative effect on drug exposure. We performed an observational study in which we collected the first steady-state pazopanib trough concentration (C min ) levels from patients treated with pazopanib 800 mg once daily (OD) taken fasted or pazopanib 600 mg OD taken with food. All patients were advised to take GAS 1 hour after pazopanib. Patients were grouped based on the use of GAS and the geometric (GM) C min levels were compared between groups for each dose regimen. Additionally, the percentage of patients with exposure below the target threshold of 20.5 mg/L and the effect of the type of PPI was explored. The GM C min levels were lower in GAS users vs non-GAS users for both the 800 and 600 mg cohorts (23.7 mg/L [95% confidence interval [CI]: 21.1-26.7] vs 28.2 mg/L [95% CI: 25.9-30.5], P = .015 and 26.0 mg/L [95% CI: 22.4-30.3] vs 33.5 mg/L [95% CI: 30.3-37.1], P = .006). Subtherapeutic exposure was more prevalent in GAS users vs non-GAS users (33.3% vs 19.5% and 29.6% vs 14%). Sub-analysis showed lower GM pazopanib C min in patients who received omeprazole, while minimal difference was observed in those receiving pantoprazole compared to non-users. Our research showed that a 1-hour time interval between intake of pazopanib and GAS did not mitigate the negative effect of GAS on pazopanib exposure and may hamper pazopanib efficacy., (© 2021 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Objectives: To determine the prevalence of Potentially Inappropriate Medication (PIMs) and Potentially Omitted Medication (POMs) in older patients with cancer., Materials and Methods: In this prospective observational study (hospital) pharmacists conducted comprehensive medication reviews in older patients with cancer (aged ≥65 years) receiving parenteral chemotherapy and/or immunotherapy at the Deventer Hospital. PIMs and POMs were identified using the Screening Tool of Older Persons' potentially inappropriate Prescriptions (STOPP), the Screening Tool to Alert doctors to the Right Treatment (START), and pharmacists' expert opinion. Recommendations regarding PIMs and POMs were communicated to the patient's oncologist/haematologist and follow-up was measured. Associations between covariates and the prevalence of PIMs and POMs were statistically analysed., Results: For the 150 patients included, 180 PIMs and 86 POMs were identified with a prevalence of 78%. Using pharmacists' expert opinion in addition to only STOPP/START criteria contributed to 49% of the PIMs and 23% of the POMs. A follow-up action was required in 73% of the 266 PIMs and POMs. Number of medicines and Charlson Comorbidity Index score were both associated with having at least one PIM and/or POM (p = .031 and p = .016, respectively)., Conclusion: The prevalence of PIMs and POMs and subsequent follow-up in older patients with cancer is high. A pharmacist-led comprehensive medication review is a good instrument to identify these PIMs and POMs and to optimize patients' treatment. A complete approach, including pharmacists' expert opinion, is recommended to identify all PIMs and POMs in clinical practice., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Pre-dialysis and dialysis patients are at risk for drug related problems (DRPs) due to a high incidence of comorbidities. Pharmacist-led medication reviews might reduce the number of DRPs., Objectives: The aim of this study was to evaluate pharmacist-led medication reviews in pre-dialysis and dialysis patients by determining the number and type of DRPs, nephrologist acceptance of pharmacist interventions and time investment., Methods: From September 2017 until December 2018, pharmacist-led medication reviews were performed on pre-dialysis and dialysis patients. DRPs (medication discrepancies, prescribing issues related to drug and dose selection, drug use problems) were identified using the pharmacists' expert opinion and the STOPP/START criteria. Number and type of accepted pharmacist interventions, sustainability of interventions after at least 1 month and time investment were determined. Practical barriers in the process were appraised., Results: One-hundred twenty five patients were reviewed: 37 pre-dialysis and 88 dialysis patients. In 100 (80%) patients 277 medication discrepancies were identified of which 224 (81%) were accepted by the nephrologist. Pharmacists suggested 422 interventions concerning drug or dose selection for 115 patients; 106 interventions were accepted by the nephrologist, which resulted in 60 patients having medication changed. Ninety percent of those changes remained implemented on follow-up after at least 1 month. In 46 (37%) patients, the clinical pharmacist detected DRPs concerning the drug use process and performed patient counseling. The average time investment was 85 min per patient for the clinical pharmacist and 15 min for the nephrologist. Besides time investment, unclear responsibility for medication management due to multiple prescribers was an important barrier in the process and the main reason for nephrologists to reject pharmacist interventions., Conclusion: Pharmacist-led medication reviews in pre-dialysis and dialysis patients led to medication changes in half of the patients. However, efficiency should be improved before adopting pharmacist-led medication reviews into clinical practice., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background Metformin associated lactic acidosis (MALA) is a serious adverse event with a high mortality rate of 30-50%. Early recognition of MALA and timely starting treatment may reduce its morbidity and mortality. Objective The aim of this study was to explore clinical parameters to identify patients with MALA in patients with suspected sepsis induced lactic acidosis in the emergency department ED. Setting A retrospective single centre study was conducted at the Deventer Teaching Hospital in the Netherlands. Method Patients with lactate concentration > 4.0 mmol/l admitted at the ED between 2010 and 2017 with suspected sepsis or confirmed MALA and referred to the Intensive Care Unit were included. Baseline characteristics (pH, lactate, creatinine and CRP) of MALA patients were compared with patients with suspected sepsis induced lactic acidosis. Creatinine and lactate concentration were selected as potential relevant parameters. Main outcome measure Sensitivity and specificity of the highest tertiles of the creatinine and the lactate concentrations separately, in combination, and both combined with metformin use, were calculated. Results Thirteen MALA and 90 suspected sepsis induced lactic acidosis patients were included. Lactate (14.7 vs 5.9 mmol/l, p < 0.01) and creatinine concentration (642 vs 174 μmol/l, p < 0.01) were significantly higher in the MALA group and arterial pH (7.04 vs 7.38, p < 0.01) and CRP (90 vs 185 mg/l, p < 0.01) were significantly lower. The combined parameters lactate ≥ 8.4 mmol/l, creatinine ≥ 256 μmol/l had a sensitivity of 85% and a specificity of 95% for identifying MALA in suspected sepsis induced lactic acidosis patients in the ED. When combined with metformin use the specificity increased to 99%. Conclusion When managing lactic acidosis in the ED the diagnosis MALA should be considered in patients with a creatinine concentration ≥ 256 μmol/l and lactate concentration ≥ 8.4 mmol/l.

Purpose: To assess whether extracorporeal treatment (ECTR) improves outcome of patients with metformin-associated lactic acidosis (MALA) and to evaluate the clinical applicability of the Extracorporeal Treatments in Poisoning Workgroup (EXTRIP) criteria for starting ECTR in metformin poisoning., Methods: Patients with metformin serum concentrations above 2 mg/l who were admitted in the Deventer Teaching Hospital between January 2000 and July 2019 and complied with the definition of MALA (pH < 7.35 and lactate concentration > 5 mmol/l) were included. Mortality and clinical parameters of patients treated with ECTR or not were compared. In addition, treatment of MALA in clinical practice was verified against the criteria of EXTRIP., Results: Forty-two patients were included. Lactate (13.8 versus 10.5 mmol/l, p = 0.01), creatinine (575 versus 254 umol/l, p < 0.01)), metformin (29.4 versus 8.6 mg/l, p < 0.01) concentrations, and vasopressor requirement (72% versus 23%, p < 0.01) were significantly higher in the ECTR-group. Blood pH (7.05 versus 7.19, p = 0.03) and bicarbonate (6 versus 11 mmol/l, p < 0.01) were significantly lower. Mortality, length of hospital stay, and mechanical ventilation requirement were not statistically different. In 83% of patients, treatment of MALA was in accordance with the EXTRIP criteria., Conclusions: Although there was no statistical benefit in mortality shown from ECTR, ECTR might be lifesaving in MALA, considering the ECTR-group was significantly sicker than the non-ECTR-group. The majority of patients were treated in line with the EXTRIP criteria. Severity of lactic acidosis and renal impairment were the main indications for initiating ECTR.

During the past two decades, small-molecule kinase inhibitors have proven to be valuable in the treatment of solid and haematological tumours. However, because of their oral administration, the intrapatient and interpatient exposure to small-molecule kinase inhibitors (SMKIs) is highly variable and is affected by many factors, such as concomitant use of food and herbs. Food-drug interactions are capable of altering the systemic bioavailability and pharmacokinetics of these drugs. The most important mechanisms underlying food-drug interactions are gastrointestinal drug absorption and hepatic metabolism through cytochrome P450 isoenzymes. As food-drug interactions can lead to therapy failure or severe toxicity, knowledge of these interactions is essential. This Review provides a comprehensive overview of published studies involving food-drug interactions and herb-drug interactions for all registered SMKIs up to Oct 1, 2019. We critically discuss US Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines concerning food-drug interactions and offer clear recommendations for their management in clinical practice., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A sensitive and selective ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous determination of seven oral oncolytics (two PARP inhibitors, i.e. olaparib and niraparib, and five tyrosine kinase inhibitors, i.e. cobimetinib, cabozantinib, dabrafenib, vemurafenib and regorafenib, plus its active metabolite regorafenib M2) in EDTA plasma was developed and validated. Stable isotope-labelled internal standards were used for each analyte. A simple protein precipitation method was performed with acetonitrile. The LC-MS/MS system consisted of an Acquity H-Class UPLC system, coupled to a Xevo TQ-S micro tandem mass spectrometer. The compounds were separated on a Waters CORTECS UPLC C18 column (2.1 × 50 mm, 1.6 μm particle size) and eluted with a gradient elution system. The ions were detected in the multiple reaction monitoring mode. The method was validated for cobimetinib, cabozantinib, dabrafenib, niraparib, olaparib, vemurafenib, regorafenib and regorafenib M2 over the ranges 6-1000, 100-5000, 10-4000, 200-2000, 200-20,000, 5000-100,000, 500-10,000 and 500-10,000 μg/L, respectively. Within-day accuracy values for all analytes ranged from 86.8 to 115.0% with a precision of <10.4%. Between-day accuracy values ranged between 89.7 and 111.9% with a between-day precision of <7.4%. The developed method was successfully used for guiding therapy with therapeutic drug monitoring in cancer patients and clinical research programs in our laboratory., (© 2019 The Authors. Biomedical Chromatography published by John Wiley & Sons Ltd.)

Pazopanib is taken fasted in a fixed oral daily dose of 800 mg. We hypothesized that ingesting pazopanib with food may improve patients' comfort and reduce gastrointestinal (GI) adverse events. Therefore, we investigated the bioequivalent dose of pazopanib when taken with food compared with 800 mg pazopanib taken fasted. In addition, we investigated the differences in GI toxicity, patient satisfaction, and patient's preference for either intake. The intake of 600 mg pazopanib with food resulted in a bioequivalent exposure and was preferred over a standard pazopanib dose without food. No differences were seen in GI toxicities under both intake regimens. Patients seem to be more positive about their feelings about side effects and satisfaction with their therapy when pazopanib was taken with food. Forty-one of the patients (68%) preferred the intake with a continental breakfast., (© 2019 The Authors Clinical Pharmacology & Therapeutics © 2019 American Society for Clinical Pharmacology and Therapeutics.)

Renal or hepatic impairment is a common comorbidity for patients with cancer either because of the disease itself, toxicity of previous anticancer treatments, or because of other factors affecting organ function, such as increased age. Because renal and hepatic function are among the main determinants of drug exposure, the pharmacokinetic profile might be altered for patients with cancer who have renal or hepatic impairment, necessitating dose adjustments. Most anticancer drugs are dosed near their maximum tolerated dose and are characterised by a narrow therapeutic index. Consequently, selecting an adequate dose for patients who have either hepatic or renal impairment, or both, is challenging and definitive recommendations on dose adjustments are scarce. In this Review, we discuss the effect of renal and hepatic impairment on the pharmacokinetics of anticancer drugs. To guide clinicians in selecting appropriate dose adjustments, information from available drug labels and from the published literature were combined to provide a practical set of recommendations for dose adjustments of 160 anticancer drugs for patients with hepatic and renal impairment., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Multikinase inhibitors (MKIs), including the tyrosine kinase inhibitors (TKIs), have rapidly become an established factor in daily (hemato)-oncology practice. Although the oral route of administration offers improved flexibility and convenience for the patient, challenges arise in the use of MKIs. As MKIs are prescribed extensively, patients are at increased risk for (severe) drug-drug interactions (DDIs). As a result of these DDIs, plasma pharmacokinetics of MKIs may vary significantly, thereby leading to high interpatient variability and subsequent risk for increased toxicity or a diminished therapeutic outcome. Most clinically relevant DDIs with MKIs concern altered absorption and metabolism. The absorption of MKIs may be decreased by concomitant use of gastric acid-suppressive agents (e.g. proton pump inhibitors) as many kinase inhibitors show pH-dependent solubility. In addition, DDIs concerning drug (uptake and efflux) transporters may be of significant clinical relevance during MKI therapy. Furthermore, since many MKIs are substrates for cytochrome P450 isoenzymes (CYPs), induction or inhibition with strong CYP inhibitors or inducers may lead to significant alterations in MKI exposure. In conclusion, DDIs are of major concern during MKI therapy and need to be monitored closely in clinical practice. Based on the current knowledge and available literature, practical recommendations for management of these DDIs in clinical practice are presented in this review., Competing Interests: Conflict of interest statement: The authors declare that there is no conflict of interest.

Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has become the standard of care in the treatment of patients with peritoneal carcinomatosis of colorectal origin. The use of oxaliplatin for HIPEC has gained popularity. Although the HIPEC procedure is adopted throughout the world, major differences exist between treatment protocols regarding the carrier solution, perfusate volume, use of an open or closed technique, duration of the perfusion and application of additional flushing. These differences can influence the pharmacokinetics and pharmacodynamics of oxaliplatin and might thereby have an impact on the efficacy and/or safety of the treatment. Clinicians should be aware of the clinical importance of oxaliplatin pharmacology when performing HIPEC surgery. This review adds new insights into the complex field of the pharmacology of HIPEC and highlights an important worldwide problem: the lack of standardization of the HIPEC procedure., (© 2018 The British Pharmacological Society.)

Background: The aim of this study was to estimate the total economic and health related burden of breast cancer in the Netherlands., Methods: Data on incidence, prevalence, mortality and survival were extracted from the Dutch National Cancer Registry and were used to calculate the economic and health related burden of breast cancer for overall, DCIS (stage 0), early- (stage I), locally advanced- (stage II-III) and metastatic- (stage IV) breast cancer by age groups and by year (if applicable)., Results: The overall incidence of breast cancer increased from 103.4 up to 153.2 per 100,000 women between 1990 and 2014. The increase was driven by DCIS and early breast cancer as the incidence of locally advanced and metastatic breast cancer remained stable. Between 1990 and 2014, ten-year overall survival rates increased from 87% to 93% for early breast cancer, 41% to 62% for locally advanced- and from 6% to 9% for metastatic disease. Annually, breast cancer in the Netherlands is responsible for approximately 3100 deaths, 26,000 life years lost, 65,000 Disability Adjusted Life Years (DALYs) and an economic burden of €1.27 billion., Conclusions: This study provides a comprehensive assessment of the burden of breast cancer and subsequent trends over time in the Netherlands.

- A new guideline: 'Intoxication: initial approach in the hospital' will be published this year. This guideline sets out the latest insights on gastrointestinal decontamination in intoxication; the advice is summarized in a flowchart.- The advice is to generally administer activated charcoal, unless there are indications that the toxin will not bind to activated charcoal or that the amount of toxin that the patient has ingested is too great; in these cases gastric lavage can be considered.- Activated charcoal can be administered up to 2 hours after the ingestion of a toxic substance, unless there are contra-indications. Multiple-dose activated charcoal in combination with a laxative can be administered in cases of overdose with toxins that use the enterohepatic circulation (such as theophylline, carbamazepine, quinine, dapsone and phenobarbital).- Gastric lavage should be limited to extremely serious intoxication, when the substance has been ingested less than 1-2 hours previously.- Whole-bowel irrigation should not be performed routinely but should be limited to ingestion of toxins with sustained release or enteric coating, or for toxins that do not bind to activated charcoal.

Aims: The prevalence of atrial fibrillation (AF) has increased over the past years due to aging of the population, and healthcare costs associated with AF reflect a significant financial burden. The aim of this study was to explore predictors for the real-world AF-related in-hospital costs in patients that recently initiated anticoagulation with acenocoumarol or dabigatran., Methods: Predictors for claimed total hospital care costs and cardiology costs in AF patients were explored by using hospital financial claims data from propensity score matched patient groups in a large Dutch community hospital. This study analyzed the total dataset (n = 766) and carried out a secondary analysis for all matched pairs of anticoagulation naïve AF patients (n = 590) by ordinal regression., Results: Dabigatran was a predictor for significantly lower cardiology and total hospital care costs (Odds Ratio [OR] = 0.43, 95% confidence interval (CI) = 0.33-0.57; and OR = 0.60, 95% CI = 0.46-0.79, respectively). Female gender was a predictor for lower total hospital care costs. Predictors for an increase in total hospital care costs were the occurrence of stroke or systemic embolism, major bleeding, and minor bleeding. The costs predictors were comparable when limiting the analysis to patients that were anticoagulation naïve. Age and CHA 2 DS 2 -VASc were not predictors for either cardiology or total hospital care costs in both analyses., Conclusion: Dabigatran treatment was as a predictor for lower cardiology costs and lower total hospital care costs in AF patients that initiated oral anticoagulation.

Tyrosine kinase inhibitors (TKIs) have rapidly become an established factor in oncology, and have been shown to be effective in a wide variety of solid and hematologic malignancies. Use of the oral administration route of TKIs offers flexibility and is convenient for the patient; however, despite these advantages, the oral route of administration also causes a highly relevant new problem. Acid-inhibitory drugs, such as proton pump inhibitors (PPIs), increase the intragastric pH, which may subsequently decrease TKI solubility, bioavailability, and treatment efficacy. Clear and practical advice on how to manage PPI use during TKI therapy is currently not available in the literature. Since PPIs are extensively used during TKI therapy, prescribers are presented with a big dilemma as to whether or not to continue the combined treatment, resulting in patients possibly being deprived of optimal therapy. When all pharmacological characteristics and data of either TKIs and PPIs are considered, practical and safe advice on how to manage this drug combination can be given.

Introduction: Many patients with intentional drug overdose (IDO) are admitted to a medium (MC) or intensive care unit (IC) without ever requiring MC/IC related interventions. The objective of this study was to develop a decision tool, using parameters readily available in the emergency room (ER) for patients with an IDO, to identify patients requiring admission to a monitoring unit., Methods: Retrospective cohort study among cases of IDO with drugs having potentially acute effects on neurological, circulatory or ventilatory function, admitted to the MC/IC unit between 2007 and 2013. A decision tool was developed, using 6 criteria, representing intubation, breathing, oxygenation, cardiac conduction, blood pressure, and consciousness. Cases were labeled as 'high acuity' if one or more criteria were present., Results: Among 255 cases of IDO that met the inclusion criteria, 197 were identified as "high acuity". Only 70 of 255 cases underwent one or more MC/IC related interventions, of which 67 were identified as 'high acuity by the decision tool (sensitivity 95.7%)., Conclusion: In a population of patients with intentional drug overdose with agents having potentially acute effect on vital functions, 95.7% of MC/IC interventions could be predicted by clinical assessment, supplemented with electrocardiogram and blood gas analysis, in the ER., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Drug-drug interactions (DDIs) are of major concern in oncology, since cancer patients typically take many concomitant medications. Retrospective studies have been conducted to determine the prevalence of DDIs. However, prospective studies on DDIs needing interventions in cancer patients have not yet been carried out. Therefore, a prospective study was designed to identify DDIs leading to interventions among ambulatory cancer patients receiving anticancer treatment., Patients and Methods: Patients starting with a new treatment regimen with i.v. or oral anticancer medication were asked to participate. The patients' medication was checked for DDIs by using drug interaction software. An expert team of clinical pharmacologists evaluated the relevance of these identified DDIs. If a DDI was qualified as potentially clinically relevant, an intervention was proposed to the treating (hemato)oncologist. Several variables were studied as determinants for performing an intervention. Descriptive statistics and uni- and multivariate logistic regression analyses were carried out., Results: In this study, 302 patients were included. A total of 603 DDIs were identified by the drug interaction software and judged by the expert team. Of all 603 DDIs, 120 DDIs were considered potentially clinically relevant. These 120 DDIs, present in a total of 81 patients, resulted in a clinical intervention already executed by the (hemato)oncologist in 39 patients (13%), while an additional intervention was proposed by a clinical pharmacologist in 42 patients (14%). The number of comorbidities and the number of 'over-the-counter' drugs were identified as determinants., Conclusions: Clinical interventions on DDIs are frequently required among patients starting with anticancer therapy. Structured screening for these potentially clinically relevant DDIs, by (hemato)oncologists in close collaborations with clinical pharmacologists, should take place before the start and during anticancer treatment., Clinical Trials Number: This study was registered at the Dutch Trial Registry under number NTR3760., (© The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)