The impact of telemonitoring on correct drug use, complications and quality of life among patients with multiple myeloma (ITUMM): A study protocol for an open-label, parallel-group, randomized controlled trial.

Introduction: Multiple myeloma (MM) is the second most common hematologic malignancy. MM is associated with significant morbidity due to its end-organ destruction and is a disease of the older population. Although survival rates for MM have improved over the last decade, due to an increase in treatment options, the disease remains incurable.

Lethal Capecitabine Toxicity in Patients With Complete Dihydropyrimidine Dehydrogenase Deficiency Due to Ultra-Rare Variants.

A DPD deficiency should be considered in case of severe toxicity even in the absence of common risk variants in DPYD.

Bleeding Complications in a Patient After the Unexpected Interaction between Valproic Acid and Phenprocoumon.

Background: Phenprocoumon is a vitamin K antagonist that is widely prescribed in Europe and Latin America for the prophylaxis and treatment of thromboembolic events.

Case Presentation: A 90-year-old female was admitted to our hospital with tonic-clonic seizures, possibly due to dementia syndrome. Valproic acid (VPA) was prescribed for the treatment of seizures.

Role of Patient-Reported Outcomes in Clinical Trials in Metastatic Colorectal Cancer: A Scoping Review.

Purpose: To perform a scoping review on the use of Patient-Reported Outcome Measures (PROMs) in randomized trials on systemic therapy in patients with metastatic colorectal cancer (mCRC) between 2010 and 2021.

Methods: First, a search on clinicaltrials.gov was performed, looking for randomized trials in mCRC.

Dihydropyrimidine Dehydrogenase Phenotyping Using Pretreatment Uracil: A Note of Caution Based on a Large Prospective Clinical Study.

In clinical practice, 25-30% of the patients treated with fluoropyrimidines experience severe fluoropyrimidine-related toxicity. Extensively clinically validated DPYD genotyping tests are available to identify patients at risk of severe toxicity due to decreased activity of dihydropyrimidine dehydrogenase (DPD), the rate limiting enzyme in fluoropyrimidine metabolism. In April 2020, the European Medicines Agency recommended that, as an alternative for DPYD genotype-based testing for DPD deficiency, also phenotype testing based on pretreatment plasma uracil levels is a suitable method to identify patients with DPD deficiency.

Effects of Pharmacogenetic Screening for CYP2D6 Among Elderly Starting Therapy With Nortriptyline or Venlafaxine: A Pragmatic Randomized Controlled Trial (CYSCE Trial).

Purpose/background: The duration of untreated depression is a predictor for poor future prognosis, making rapid dose finding essential. Genetic variation of the CYP2D6 isoenzyme can influence the optimal dosage needed for individual patients. The aim of this study was to determine the effectiveness of CYP2D6 pharmacogenetic screening to accelerate drug dosing in older patients with depression initiating nortriptyline or venlafaxine.

Cross-national comparison of medication use in Australian and Dutch nursing homes.

Background: cross-national comparisons can be used to explore therapeutic areas and identify potential medication issues.

Methods: we used cross-sectional pharmacy supply data to explore medication use for nursing home residents in Australia (AU n = 26 homes, 1,560 residents) and the Netherlands (NL n = 6 homes, 2,037 residents). Binary logistic regression analysis was used to calculate the sex and aged adjusted odds ratios (OR) and associated 95% confidence intervals with a flexible Bonferroni-Holm procedure used to adjust for multiple hypothesis testing.

Genotypes Affecting the Pharmacokinetics of Anticancer Drugs.

Cancer treatment is becoming more and more individually based as a result of the large inter-individual differences that exist in treatment outcome and toxicity when patients are treated using population-based drug doses. Polymorphisms in genes encoding drug-metabolizing enzymes and transporters can significantly influence uptake, metabolism, and elimination of anticancer drugs. As a result, the altered pharmacokinetics can greatly influence drug efficacy and toxicity.

A clinical validation study for application of DBS in therapeutic drug monitoring of antidepressants.

Background: A bridging study of plasma and DBS concentrations for therapeutic drug monitoring of antidepressants was performed. RESULTS & METHODOLOGY: Potassium-based hematocrit analysis was included. In addition, we defined acceptance criteria based on the differences between individual data points of plasma and DBS concentrations.

Evaluation of an oral uracil loading test to identify DPD-deficient patients using a limited sampling strategy.

Aim: Dihydropyrimidine dehydrogenase (DPD) deficiency can lead to severe toxicity following 5-fluorouracil (5FU) or capecitabine (CAP) treatment. Uracil (U) can be used as a probe to determine systemic DPD activity. The present study was performed to assess the sensitivity and specificity of a U loading dose for detecting DPD deficiency.

Influence of metastatic disease on the usefulness of uracil pharmacokinetics as a screening tool for DPD activity in colorectal cancer patients.

Purpose: Dihydropyrimidine dehydrogenase (DPD) deficiency can lead to severe toxicity in patients treated with a standard dose of a fluoropyrimidine such as 5-fluorouracil or capecitabine (CAP). Administration of oral uracil and subsequent measurement of uracil and dihydrouracil (DHU) plasma concentrations has been used to identify patients with DPD deficiency. Liver metastasis might influence systemic DPD activity.

Effects and cost-effectiveness of pharmacogenetic screening for CYP2D6 among older adults starting therapy with nortriptyline or venlafaxine: study protocol for a pragmatic randomized controlled trial (CYSCEtrial).

Background: Nortriptyline and venlafaxine are commonly used antidepressants for treatment of depression in older patients. Both drugs are metabolized by the polymorphic cytochrome P450-2D6 (CYP2D6) enzyme and guidelines for dose adaptations based on the CYP2D6 genotype have been developed. The CYP2D6 Screening Among Elderly (CYSCE) trial is designed to address the potential health and economic value of genotyping for CYP2D6 in optimizing dose-finding of nortriptyline and venlafaxine.

Evaluation of 5-fluorouracil pharmacokinetic models and therapeutic drug monitoring in cancer patients.

5-fluorouracil (5-FU) remains the cornerstone of all currently applied regimens for the treatment of patients with cancers of the gastrointestinal tract, breast, and head and neck. Unfortunately, a large variation in the clearance of 5-FU has been observed between patients, suggesting that some patients might receive nonoptimal 5-FU doses. However, therapeutic drug monitoring of 5-FU has been shown to result in reduced intra- and inter-individual variability in 5-FU plasma levels and pharmacokinetically guided dose adjustments of 5-FU-containing therapy results in a significantly improved efficacy and tolerability.

Evaluation of 5-fluorouracil pharmacokinetics in cancer patients with a c.1905+1G>A mutation in DPYD by means of a Bayesian limited sampling strategy.

Background And Objective: Dihydropyrimidine dehydrogenase (DPD) is the initial enzyme in the catabolism of 5-fluorouracil (5FU) and DPD deficiency is an important pharmacogenetic syndrome. So far, only very limited information is available regarding the pharmacokinetics of 5FU in patients with a (partial) DPD deficiency and no limited sampling models have been developed taking into account the non-linear pharmacokinetic behaviour of 5FU. The aim of this study was to evaluate the pharmacokinetics of 5FU and to develop a limited sampling strategy to detect decreased 5FU elimination in patients with a c.

Pharmacokinetics of orally administered uracil in healthy volunteers and in DPD-deficient patients, a possible tool for screening of DPD deficiency.

Purpose: Dihydropyrimidine dehydrogenase (DPD) deficiency can lead to severe toxicity in patients treated with standard doses of 5-fluorouracil (5-FU). Oral uracil administration and subsequent measurement of uracil and dihydrouracil (DHU) plasma concentrations might detect patients with DPD deficiency. This study compares the pharmacokinetics of uracil and DHU after oral uracil administration in subjects with normal and deficient DPD status.

Intragenic deletions and a deep intronic mutation affecting pre-mRNA splicing in the dihydropyrimidine dehydrogenase gene as novel mechanisms causing 5-fluorouracil toxicity.

Dihydropyrimidine dehydrogenase (DPD) is the initial enzyme acting in the catabolism of the widely used antineoplastic agent 5-fluorouracil (5FU). DPD deficiency is known to cause a potentially lethal toxicity following administration of 5FU. Here, we report novel genetic mechanisms underlying DPD deficiency in patients presenting with grade III/IV 5FU-associated toxicity.

Gemcitabine and epirubicin plasma concentration-related excretion in saliva in patients with non-small cell lung cancer.

Aim: The excretion in saliva of gemcitabine and its metabolite 2',2'-difluorodeoxyuridine (dFdU) as well as epirubicin (Epi) and its metabolite epirubicinol (Epi-ol) was studied in patients with non-small cell lung cancer, treated with gemcitabine plus epirubicin.

Methods: Patients (n = 12) were treated with gemcitabine 1125 mg/m, followed by Epi 100 mg/m. Blood, saliva, and oral mucosa cells were collected during 22 hours for analysis of gemcitabine, Epi, and their metabolites.

Pharmacokinetics of gemcitabine in non-small-cell lung cancer patients: impact of the 79A>C cytidine deaminase polymorphism.

Objective: To study the impact of the 79A>C polymorphism in the cytidine deaminase (CDA) gene on the pharmacokinetics of gemcitabine and its metabolite 2',2'-difluorodeoxyuridine (dFdU) in non-small-cell lung cancer (NSCLC) patients.

Patients And Methods: Patients (n = 20) received gemcitabine 1,125 mg/m(2) as a 30 min i.v.

A simple and sensitive fully validated HPLC-UV method for the determination of 5-fluorouracil and its metabolite 5,6-dihydrofluorouracil in plasma.

The authors developed a simple and sensitive, fully validated HPLC-UV method for the determination of both 5-FU and its metabolite DHFU in small-volume plasma samples. The analytes were separated on a 4.6 x 250 mm ID Atlantis dC18 5-microm column with isocratic elution at room temperature.

Selective targeting of homologous DNA recombination repair by gemcitabine.

Purpose: Gemcitabine (2',2'-difluoro-2'-deoxycytidine, dFdC) is a potent radiosensitizer. The mechanism of dFdC-mediated radiosensitization is yet poorly understood. We recently excluded inhibition of DNA double-strand break (DSB) repair by nonhomologous end-joining (NHEJ) as a means of radiosensitization.

Determination of epirubicin and its metabolite epirubicinol in saliva and plasma by HPLC.

We present a high-performance liquid chromatography (HPLC) method suitable for the analysis of epirubicin and its metabolite epirubicinol in saliva and plasma. Preparation of saliva and plasma samples was performed by extraction of analytes with a chloroform:2-propanol mixture (6:1, vol/vol) and evaporation of the organic phase to dryness under vacuum at a temperature of approximately 45 degrees C. The chromatographic analysis was carried out by reversed-phase isocratic elution of the anthracyclines with a Chromsep stainless steel HPLC column (150 x 4.

Extensive hepatic replacement due to liver metastases has no effect on 5-fluorouracil pharmacokinetics.

Purpose: The influence of liver metastases on the pharmacokinetics of 5-fluorouracil (5-FU) and its metabolite 5,6-dihydrofluorouracil (DHFU) was studied in patients with liver metastases from gastrointestinal cancer ( n=16) and compared with a control group of patients with nonmetastatic gastrointestinal cancer ( n=18).

Methods: Patients were assigned to two different groups based on the presence of liver metastases. The percentage of hepatic replacement was determined with CT and ultrasonography and classified as <25%, 25-50% or >50% of the total liver volume.