Chronopharmacology in Therapeutic Drug Monitoring—Dependencies between the Rhythmics of Pharmacokinetic Processes and Drug Concentration in Blood

The objective of the optimization of pharmacotherapy compliant with the basic rules of clinical pharmacology is its maximum individualization, ensuring paramount effectiveness and security of the patient’s therapy. Thus, multiple factors that are decisive in terms of uniqueness of treatment of the given patient must be taken into consideration, including, but not limited to, the patient’s age, sex, concomitant diseases, special physiological conditions (e.g., pregnancy, lactation, extreme age groups), polypharmacotherapy and polypragmasia (particularly related to increased risk of drug interactions), and patient’s phenotypic response to the administered drug with possible genotyping. Conducting therapy while monitoring the concentration of certain drugs in blood (Therapeutic Drug Monitoring; TDM procedure) is also one of the factors enabling treatment individualization. Furthermore, another material, and yet still a marginalized pharmacotherapeutic factor, is chronopharmacology, which indirectly determines the values of drug concentrations evaluated in the TDM procedure. This paper is a brief overview of chronopharmacology, especially chronopharmacokinetics, and its connection with the clinical interpretation of the meaning of the drug concentrations determined in the TDM procedure.

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Real-life isoniazid and rifampicin plasma concentrations in children: a tool for therapeutic drug monitoring of tuberculosis

BMC Infectious Diseases ◽

10.1186/s12879-021-06764-7 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Chiara Tersigni ◽

Giulia Boiardi ◽

Lorenzo Tofani ◽

Elisabetta Venturini ◽

Carlotta Montagnani ◽

...

Keyword(s):

Plasma Concentration ◽

Therapeutic Drug Monitoring ◽

Drug Monitoring ◽

Venous Blood ◽

Plasma Concentrations ◽

Age Groups ◽

Real Life ◽

Therapeutic Drug ◽

Blood Samples ◽

Drug Concentrations

Abstract Background Low plasma levels of first-line antitubercular drugs can be counted among the main causes of poor response to antitubercular therapy, and therapeutic drug monitoring has been proposed as a method to promote tailored treatments for both child and adult patients. The main aim of the study was to evaluate serum concentrations of isoniazid (INH) and rifampicin (RIF) and to investigate reasons for sub-therapeutic plasma concentrations in order to fix dosages. Methods Children with TB were prospectively enrolled from January to August 2019. Two venous blood samples were collected (the first at least 15 days after the beginning of antitubercular treatment, and the second between 1 and 8 weeks later). Plasma concentrations were determined by a validated high-performance liquid chromatography method. Results In all, 45 children were included. Seventy blood samples for INH plasma concentration were collected between 120 and 240 min after drug intake. Adjusting for dose (mg/kg/day) and time of INH administration, when considering three different age groups (≤ 2 years, 2–12 years, > 12 years), a statistically significant lower INH plasma concentration was observed in younger children compared to the older age groups in the multivariate analysis (p < 0.001 and p < 0.001). A total of 68 blood samples were evaluated for RIF concentrations. Both for INH and RIF a statistically significant lower plasma concentration was also observed in adolescents (p < 0.001). Fifteen children (15/45, 33%) presented drug concentrations under the referral therapeutic range. Conclusions Based on our findings, monitoring patients’ drug plasma concentrations in children under 2 years of age and in adolescents can make treatment more patient-tailored.

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Therapeutic Drug Monitoring of Biologics in IBD: Essentials for the Surgical Patient

Journal of Clinical Medicine ◽

10.3390/jcm10235642 ◽

2021 ◽

Vol 10 (23) ◽

pp. 5642

Author(s):

Rodrigo Bremer Nones ◽

Phillip R. Fleshner ◽

Natalia Sousa Freitas Queiroz ◽

Adam S. Cheifetz ◽

Antonino Spinelli ◽

...

Keyword(s):

Postoperative Complications ◽

Therapeutic Drug Monitoring ◽

Drug Monitoring ◽

Quality Data ◽

Therapeutic Drug ◽

Surgical Patient ◽

Serum Concentrations ◽

Drug Concentrations ◽

Clinical Scenarios ◽

Increased Risk

Despite significant development in the pharmacological treatment of inflammatory bowel diseases (IBD) along with the evolution of therapeutic targets and treatment strategies, a significant subset of patients still requires surgery during the course of the disease. As IBD patients are frequently exposed to biologics at the time of abdominal and perianal surgery, it is crucial to identify any potential impact of biological agents in the perioperative period. Even though detectable serum concentrations of biologics do not seem to increase postoperative complications after abdominal procedures in IBD, there is increasing evidence on the role of therapeutic drug monitoring (TDM) in the perioperative setting. This review aims to provide a comprehensive summary of published studies reporting the association of drug concentrations and postoperative outcomes, postoperative recurrence (POR) after an ileocolonic resection for Crohn’s disease (CD), colectomy rates in ulcerative colitis (UC), and perianal fistulizing CD outcomes in patients treated with biologics. Current data suggest that serum concentrations of biologics are not associated with an increased risk in postoperative complications following abdominal procedures in IBD. Moreover, higher concentrations of anti-TNF agents are associated with a reduction in colectomy rates in UC. Finally, higher serum drug concentrations are associated with reduced rates of POR after ileocolonic resections and increased rates of perianal fistula healing in CD. TDM is being increasingly used to guide clinical decision making with favorable outcomes in many clinical scenarios. However, given the lack of high quality data deriving mostly from retrospective studies, the evidence supporting the systematic application of TDM in the perioperative setting is still inconclusive.

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Abstract 11598: Is Therapeutic Drug Monitoring of Direct Anticoagulants Really Unnecessary?

Circulation ◽

10.1161/circ.132.suppl_3.11598 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Bernadette Baldin ◽

Marion Warembourg ◽

Guillaume Bardy ◽

Loïc Startari ◽

Fanny Rocher ◽

...

Keyword(s):

Therapeutic Drug Monitoring ◽

Drug Monitoring ◽

Medical Center ◽

Oral Anticoagulants ◽

Direct Oral Anticoagulants ◽

Plasma Concentrations ◽

Therapeutic Drug ◽

Drug Concentrations ◽

Increased Risk ◽

Direct Anticoagulants

Introduction: no routine monitoring is deemed necessary with direct oral anticoagulants dabigatran (D) and rivaroxaban(R). Yet, their misuse may lead to inefficacy or increased risk of bleeding. Hypothesis: due to the prevalence of elderly patients in our medical center, the pharmacology department was asked to measure R and D plasma concentrations. Therefore we aimed not only to check their prescription adequacy but also to evaluate whether bleeding or thrombosis adverse events were associated with drug concentrations clearly outside of their expected “normal” range. Methods: Patients receiving R or D for either AFib, deep venous thrombosis or its prevention were included and had blood samples drawn for drug measurements, by HPLC-tandem mass spectrometry. Adequacy of the patient prescription was checked by pharmacists according D & R respective SmPCs. A robust and conservative method was applied to evaluate anticoagulant concentrations : D & R concentrations were blindly deemed “normal” when within the [IC] 95 limits (peak and trough, relative to the dose) observed in the respective RE-LY and Rocket-AF pivotal studies, as compared to “out of range” when outside of these limits. Results: 287 consecutive patients from our center had their concentration of R (n=219 : 76%) or D (n = 68 : 24%) measured. The inadequacy of the prescriptions was 31.4% alltogether. Seventy patients presented with bleeding (n = 48, 17%) or thrombosis (n = 22, 8%), that either led to their admission in emergency, or occurred in the hospital wards. Bleedings and thrombosis were significantly associated with out-of-range concentrations (p<0.01). Patients with hemorrhages had higher concentrations (R: 194 VS 83 μg.l -1 and D: 128 VS 80 μg.l -1 ) whereas thrombosis were associated with lower ones (R: 75 VS 106 μg.l -1 D: 29 VS 93 μg.l -1 ). HAS-BLED Score was 2.0 ± 0.9 for bleeding cases as compared to 1.5 ± 0.9 (p<0.01). Conclusions: therapeutic drug monitoring of direct oral anticoagulants might not be superfluous, at least for R & D, especially in patients with a higher score HAS-BLED.

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Pharmacokinetics/Pharmacodynamics of β-Lactams and Therapeutic Drug Monitoring: From Theory to Practical Issues in the Intensive Care Unit

Seminars in Respiratory and Critical Care Medicine ◽

10.1055/s-0039-1693498 ◽

2019 ◽

Vol 40 (04) ◽

pp. 476-487 ◽

Cited By ~ 3

Author(s):

Paul Williams ◽

Menino Osbert Cotta ◽

Jason A. Roberts

Keyword(s):

Steady State ◽

Therapeutic Drug Monitoring ◽

Critically Ill ◽

Drug Monitoring ◽

Critically Ill Patients ◽

Product Information ◽

Dose Optimization ◽

Therapeutic Drug ◽

Drug Concentrations ◽

Increased Risk

AbstractDespite therapeutic advances over recent decades, the mortality rate for sepsis and septic shock is still approximately 25% worldwide. Early administration of appropriate intravenous antibiotics in the right dose is one of the cornerstones of treatment of sepsis. β-Lactam antibiotics are the most commonly prescribed in critically ill patients, and dosages that do not achieve specific pharmacokinetic/pharmacodynamic targets may increase the likelihood of treatment failure and even emergence of antibiotic resistance. Fluctuations in physiological parameters are often observed in critically ill patients, leading to altered pharmacokinetics and increased risk of suboptimal exposures, especially if standard dosing according to the product information is prescribed. Contemporary evidence illustrates that therapeutic β-lactam concentrations are inconsistently achieved at steady state. This review will investigate alternative β-lactam dose optimization strategies including prolonged infusions, guideline-based dosing, therapeutic drug monitoring (TDM), and the use of dose optimization software, all of which aim to increase the likelihood of achieving therapeutic drug concentrations and improve clinical outcomes as compared with the standard dosing approach. These dose optimization strategies have been the subject of a growing body of evidence; however, further investigation into the outcome benefits and validity of both non-TDM and TDM dosing strategies is required. For the clinician, it is important to select a feasible dosing strategy tailored for the individual patient, which will maximize the likelihood of achieving therapeutic concentrations at steady state and maintain these exposures throughout the course of therapy.

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Rapid point-of-care anti-infliximab antibodies detection in clinical practice: comparison with ELISA and potential for improving therapeutic drug monitoring in IBD patients

Therapeutic Advances in Gastroenterology ◽

10.1177/1756284821999902 ◽

2021 ◽

Vol 14 ◽

pp. 175628482199990

Author(s):

Sonia Facchin ◽

Andrea Buda ◽

Romilda Cardin ◽

Nada Agbariah ◽

Fabiana Zingone ◽

...

Keyword(s):

Clinical Practice ◽

Therapeutic Drug Monitoring ◽

Drug Monitoring ◽

Point Of Care ◽

Drug Clearance ◽

Elisa Test ◽

Enzyme Linked Immunosorbent Assay ◽

Therapeutic Drug ◽

Drug Concentrations ◽

Inflammatory Bowel

Anti-drug antibodies can interfere with the activity of anti-tumor necrosis factor (TNF) agents by increasing drug clearance via direct neutralization. The presence of anti-drug antibodies is clinically relevant when trough drug concentrations are undetectable or sub-therapeutic. However, traditional immunoassay is not easily and rapidly accessible, making the translation of the results into treatment adjustment difficult. The availability of a point-of-care (POC) test for therapeutic drug monitoring (TDM) might represent an important step forward for improving the management of inflammatory bowel disease (IBD) patients in clinical practice. In this pilot study, we compared the results obtained with POC tests with those obtained by enzyme-linked immunosorbent assay (ELISA) in a group of IBD patients treated with Infliximab (IFX). We showed that POC test can reliably detect presence of antibody-to-IFX with 100% of specificity and 76% sensitivity, in strong agreement with the ELISA test ( k-coefficient = 0.84).

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Immunosuppressant quantification in intravenous microdialysate – towards novel quasi-continuous therapeutic drug monitoring in transplanted patients

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2020-1542 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Susanne Weber ◽

Sara Tombelli ◽

Ambra Giannetti ◽

Cosimo Trono ◽

Mark O’Connell ◽

...

Keyword(s):

Therapeutic Drug Monitoring ◽

Real Time ◽

Drug Monitoring ◽

Time Course ◽

Drug Dosage ◽

Immunosuppressive Drug ◽

Therapeutic Drug ◽

Continuous Sampling ◽

Real Time Analysis ◽

Drug Concentrations

AbstractObjectivesTherapeutic drug monitoring (TDM) plays a crucial role in personalized medicine. It helps clinicians to tailor drug dosage for optimized therapy through understanding the underlying complex pharmacokinetics and pharmacodynamics. Conventional, non-continuous TDM fails to provide real-time information, which is particularly important for the initial phase of immunosuppressant therapy, e.g., with cyclosporine (CsA) and mycophenolic acid (MPA).MethodsWe analyzed the time course over 8 h of total and free of immunosuppressive drug (CsA and MPA) concentrations measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in 16 kidney transplant patients. Besides repeated blood sampling, intravenous microdialysis was used for continuous sampling. Free drug concentrations were determined from ultracentrifuged EDTA-plasma (UC) and compared with the drug concentrations in the respective microdialysate (µD). µDs were additionally analyzed for free CsA using a novel immunosensor chip integrated into a fluorescence detection platform. The potential of microdialysis coupled with an optical immunosensor for the TDM of immunosuppressants was assessed.ResultsUsing LC-MS/MS, the free concentrations of CsA (fCsA) and MPA (fMPA) were detectable and the time courses of total and free CsA comparable. fCsA and fMPA and area-under-the-curves (AUCs) in µDs correlated well with those determined in UCs (r≥0.79 and r≥0.88, respectively). Moreover, fCsA in µDs measured with the immunosensor correlated clearly with those determined by LC-MS/MS (r=0.82).ConclusionsThe new microdialysis-supported immunosensor allows real-time analysis of immunosuppressants and tailor-made dosing according to the AUC concept. It readily lends itself to future applications as minimally invasive and continuous near-patient TDM.

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Pharmacokinetic Properties of New Antiepileptic Drugs

Journal of Pharmacy Practice ◽

10.1177/0897190005282733 ◽

2005 ◽

Vol 18 (6) ◽

pp. 444-460 ◽

Cited By ~ 8

Author(s):

Michele Y. Splinter

Keyword(s):

Therapeutic Drug Monitoring ◽

Drug Interactions ◽

Antiepileptic Drugs ◽

Drug Monitoring ◽

The United States ◽

Therapeutic Drug ◽

Kinetic Properties ◽

New Antiepileptic Drugs ◽

Drug Concentrations ◽

Pharmacokinetic Properties

Eight new antiepileptic drugs (AEDs) have been approved for use within the United States within the past decade. They are felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate, and zonisamide. These afford clinicians with more options to increase efficacy and tolerability in the treatment of patients with epilepsy. Pharmacokinetic properties and drug interactions with other AEDs and other medications taken for comorbidities are individually discussed for each of these new agents. Drug concentrations are not routinely monitored for these newer agents, and there have been few studies designed to investigate their concentration-effect relationships. For most of these medications, the concentrations observed in responders and nonresponders overlap considerably and levels associated with efficacy are often associated with adverse events, complicating the definition of target ranges. Also, epilepsy manifests itself sporadically causing difficulty in clinically monitoring efficacy of medications. Therapeutic drug monitoring provides for the individualization of treatment for these agents, which is important because they demonstrate significant variability in inter- and intraindividual pharmaco-kinetic properties. Therapeutic drug monitoring also allows for identification of noncompliance, drug interactions, and toxicity. Current knowledge of the relationships between efficacy, toxicity, and drug concentrations is discussed.

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N22 Nurse led therapeutic drug monitoring (TDM) of Infliximab in IBD

Journal of Crohn s and Colitis ◽

10.1093/ecco-jcc/jjz203.1005 ◽

2020 ◽

Vol 14 (Supplement_1) ◽

pp. S667-S668

Author(s):

S Gleeson ◽

K Sugrue ◽

M Buckley ◽

J McCarthy

Keyword(s):

Therapeutic Drug Monitoring ◽

Trough Concentration ◽

Drug Monitoring ◽

Response Assessment ◽

Symptom Improvement ◽

Therapeutic Drug ◽

Serum Samples ◽

Drug Concentrations ◽

Biologic Response ◽

Trough Levels

Abstract Background Therapeutic drug monitoring (TDM) is the clinical practice of measuring serum drug concentrations to guide clinical decision making. Achieving therapeutic drug concentrations has been associated with clinical, endoscopic and histological outcomes in IBD. The use of TDM offers a more personalised treatment approach and is associated with sustained clinical remission. Proactive TDM was introduced to the Mercy University Hospital in 2014 for all patients on biologics. Methods One hundred patients receiving biologic infusion (Infliximab) were evaluated post induction (week 12) for therapeutic drug trough concentration and for clinical response. Serum samples were taken from all IBD patients at week 12. Biologic response assessment forms were complete for all patients to assess symptom improvement. Results Thirty-five per cent of patients had sub therapeutic trough levels at week 12. They subsequently received 3 increased doses of 10mgs/kg and levels were rechecked. Of these 90% achieved therapeutic levels after the dose escalation. 65% of patients had therapeutic levels at week 12. There was a correlation between therapeutic trough levels and patient reported improvement of clinical symptoms in 85% of respondents. Conclusion TDM in our unit facilitates appropriate dose 100 patients receiving biologic infusion (Infliximab) were evaluated post induction (week 12) for therapeutic drug trough concentration and for clinical response. Serum samples were taken from all IBD patients at week 12. Biologic response assessment forms were complete for all patients to assess symptom improvement.

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Therapeutic drug monitoring in special populations

Clinical Chemistry ◽

10.1093/clinchem/44.2.415 ◽

1998 ◽

Vol 44 (2) ◽

pp. 415-419 ◽

Cited By ~ 20

Author(s):

Philip D Walson

Keyword(s):

Therapeutic Drug Monitoring ◽

Drug Monitoring ◽

Diagnostic Testing ◽

Drug Effects ◽

Special Populations ◽

Therapeutic Drug ◽

Drug Reactions ◽

Drug Concentrations ◽

Dosing Regimens ◽

Multiple Drugs

Abstract Therapeutic drug monitoring (TDM) is commonly used to maintain “therapeutic” drug concentrations. Even in compliant patients, with “average” drug kinetics, TDM is useful to identify the causes of unwanted or unexpected responses, prevent unnecessary diagnostic testing, improve clinical outcomes, and even save lives. TDM has greatest promise in certain special populations who are: (a) prone to under- or overrespond to usual dosing regimens, (b) least able to tolerate, recognize, or communicate drug effects, or who are (c) intentionally or accidentally misdosed. TDM is especially useful in patients at the extremes of age, in adolescents, and in patients who are either taking multiple drugs or expressing unusual pharmacokinetics as a result of physiological, environmental, or genetic causes. Less-well-appreciated uses of TDM include prevention of dangerousunderdosing of patients, investigation of adverse drug reactions, and identification of serious medication errors, even for a number of drugs that are not traditionally monitored. TDM can be useful for some drugs in any patient and for most drugs in some special populations.

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Therapeutic Drug Monitoring of Piperacillin-Tazobactam Using Spent Dialysate Effluent in Patients Receiving Continuous Venovenous Hemodialysis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00548-10 ◽

2010 ◽

Vol 55 (2) ◽

pp. 557-560 ◽

Cited By ~ 25

Author(s):

Michael J. Connor ◽

Charbel Salem ◽

Seth R. Bauer ◽

Christina L. Hofmann ◽

Joseph Groszek ◽

...

Keyword(s):

Therapeutic Drug Monitoring ◽

Drug Monitoring ◽

Kidney Injury ◽

Therapeutic Drug ◽

Plasma Drug ◽

Drug Dosing ◽

Drug Levels ◽

Drug Concentrations ◽

Continuous Venovenous Hemodialysis ◽

Dosing Strategies

ABSTRACTSepsis and multisystem organ failure are common diagnoses affecting nearly three-quarters of a million Americans annually. Infection is the leading cause of death in acute kidney injury, and the majority of critically ill patients who receive continuous dialysis also receive antibiotics. Dialysis equipment and prescriptions have gradually changed over time, raising concern that current drug dosing recommendations in the literature may result in underdosing of antibiotics. Our research group directed its attention toward antibiotic dosing strategies in patients with acute renal failure (ARF), and we sought data confirming that patients receiving continuous dialysis and antibiotics actually were achieving therapeutic plasma drug levels during treatment. In the course of those investigations, we explored “fast-track” strategies to estimate plasma drug concentrations. As most antimicrobial antibiotics are small molecules and should pass freely through modern high-flux hemodialyzer filters, we hypothesized that continuous renal replacement therapy (CRRT) effluent could be used as the medium for drug concentration measurement by reverse-phase high-pressure liquid chromatography (HPLC). Here we present the first data demonstrating this approach for piperacillin-tazobactam. Paired blood and dialysate trough-peak-trough samples were drawn from 19 patients receiving piperacillin-tazobactam and continuous venovenous hemodialysis (CVVHD). Total, free, and dialysate drug concentrations were measured by HPLC. Dialysate drug levels predicted plasma free drug levels well (r2= 0.91 and 0.92 for piperacillin and tazobactam, respectively) in all patients. These data suggest a strategy for therapeutic drug monitoring that minimizes blood loss from phlebotomy and simplifies analytic procedures.

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