Therapeutic drug monitoring: how to improve drug dosage and patient safety in tuberculosis treatment

In this article we describe the key role of tuberculosis (TB) treatment, the challenges (mainly the emergence of drug resistance), and the opportunities represented by the correct approach to drug dosage, based on the existing control and elimination strategies. In this context, the role and contribution of therapeutic drug monitoring (TDM) is discussed in detail. Treatment success in multidrug-resistant (MDR) TB cases is low (62%, with 7% failing or relapsing and 9% dying) and in extensively drug-resistant (XDR) TB cases is even lower (40%, with 22% failing or relapsing and 15% dying). The treatment of drug-resistant TB is also more expensive (exceeding €50,000 for MDR-TB and €160,000 for XDR-TB) and more toxic if compared to that prescribed for drug-susceptible TB. Appropriate dosing of first- and second-line anti-TB drugs can improve the patient's prognosis and lower treatment costs. TDM is based on the measurement of drug concentrations in blood samples collected at appropriate times and subsequent dose adjustment according to the target concentration. The 'dried blood spot' technique offers additional advantages, providing the rationale for discussions regarding a possible future network of selected, quality-controlled reference laboratories for the processing of dried blood spots of difficult-to-treat patients from reference TB clinics around the world.

GOSPEL 2 - Colchicine for the treatment of gout flares in France - a GOSPEL survey subgroup analysis. Doses used in common practices regardless of renal impairment and age

OBJECTIVES

The objective of this sub-study was to assess the use of colchicine for the treatment of gout flares in real life conditions in the GOSPEL cohort following the 2006 EULAR recommendations for gout management.

METHODS

This national cross-sectional epidemiologic survey included outpatients with gout suffering from acute flare followed by randomly selected primary care physicians (n=398) and private practice rheumatologists (n=109) between October 2008 and September 2009 in France. Data regarding patient characteristics and treatment prescription was collected by each physician. Glomerular filtration rate (eGFR) was estimated using the Cockroft-Gault formula. Patients included in the survey for a gout flare filled in a specific self-questionnaire including colchicine effective intake and pain relief (numeric scale).

RESULTS

This analysis focused on the 349 patients presenting with gout flare and treated with colchicine. Mean (±SD) prescribed dose of colchicine was 2.8 (±0.7) mg within the first 24hours and the cumulative dose over the first three days of treatment was 6.9 (±1.8) mg. Patients with mild decline in eGFR (eDFG 60-80mL/min) were prescribed an average initial dose of 2.8mg (±0.8) mg (n=58), 2.7 (±0.8) mg in chronic kidney disease (CKD) stage 3 (n=43) and 2.5 (±0.7) mg in CKD stage 4 (n=2). Cumulative doses of colchicine did not take into account either renal impairment or age.

CONCLUSIONS

This study draws attention to some misuse of colchicine in daily practice and the prescription of excessive doses especially in case of renal impairment. eGFR should be enforced in daily practice.

Comparison against current standards of a DNA aptamer for the label-free quantification of tobramycin in human sera employed for therapeutic drug monitoring

The use of DNA aptamers in biosensors for the quantification of pharmaceuticals in the clinics would help to overcome the limitations of antibody-based detection for small molecules. The interest for such systems is proven by the ever-increasing number of aptamer-based solutions for analytics proposed in the literature as proof-of-concept demonstrators. Despite such diversity, these platforms often lack a comparative assessment of their performances against the current standard of practice in the clinics when using real samples. We employed an aptamer against tobramycin discovered in our laboratory to quantify through surface plasmon resonance the concentration of the antibiotic in clinical samples obtained from patients treated with tobramycin and undergoing therapeutic drug monitoring. We then compared the performances of our detection strategy against the current standard of practice. Our results show how, using adequate calibration and matrix complexity reduction, DNA aptamer-based direct assays can assess clinically relevant concentrations of small molecules in patient serum and with good correlation to current standards used in the clinics.

Optimal dose of gemcitabine for the treatment of biliary tract or pancreatic cancer in patients with liver dysfunction

A clear consensus does not exist about whether the initial dose of gemcitabine, an essential anticancer antimetabolite, should be reduced in patients with liver dysfunction. Adult patients with biliary tract or pancreatic cancer were divided into three groups according to whether they had mild, moderate, or severe liver dysfunction, evaluated on the basis of serum bilirubin and liver transaminase levels at baseline. As anticancer treatment, gemcitabine at a dose of 800 or 1000 mg/m(2) was given as an i.v. infusion once weekly for 3 weeks of a 4-week cycle. The patients were prospectively evaluated for adverse events during the first cycle, and the pharmacokinetics of gemcitabine and its inactive metabolite, difluorodeoxyuridine, were studied to determine the optimal initial dose of gemcitabine as monotherapy according to the severity of liver dysfunction. A total of 15 patients were studied. Liver dysfunction was mild in one patient, moderate in six, and severe in eight. All 15 patients had been undergoing biliary drainage for obstructive jaundice when they received gemcitabine. Grade 3 cholangitis developed in one patient with moderate liver dysfunction who received gemcitabine at the dose level of 1000 mg/m(2). No other patients had severe treatment-related adverse events resulting in the omission or discontinuation of gemcitabine treatment. The plasma concentrations of gemcitabine and difluorodeoxyuridine were similar among the groups. An initial dose reduction of gemcitabine as monotherapy for the treatment of biliary tract or pancreatic cancers is not necessary for patients with hyperbilirubinemia, provided that obstructive jaundice is well managed. (Clinical trial registration no. UMIN000005363.)

Tyrosine Kinase Inhibitor Dosing Patterns in Elderly Patients With Chronic Myeloid Leukemia

INTRODUCTION

Tyrosine kinase inhibitors (TKIs) improve the survival rate of patients with chronic myeloid leukemia (CML). However, elderly patients often experience adverse events and require dose adjustments, leading to dose interruptions or treatment discontinuation. We therefore investigated TKI dosing patterns and subsequent outcomes in elderly CML patients.

PATIENTS AND METHODS

Using the National Health Information Database, we identified patients with CML aged ≥ 70 years who were prescribed TKIs (imatinib, dasatinib, nilotinib, or radotinib) during 2007-2013. Data on age, sex, prescribed medication, and date of death were extracted.

RESULTS

Among the 378 patients, the median age was 75 (range, 70-92) years; the median follow-up period was 53 (range, 1-133) months. Imatinib, dasatinib, nilotinib, and radotinib were prescribed to 324 (85.7%), 110 (29.1%), 93 (24.6%), and 15 (4.0%) patients, respectively. In 42 patients (12.2%), the initial dose was lower than the recommended dose for chronic-phase CML. At last follow-up, 249 patients (65.9%) were receiving a reduced dose. The mean ± standard deviation dose densities of imatinib, dasatinib, nilotinib, and radotinib were 207 ± 121.6, 29 ± 26.7, 235 ± 197, and 123 ± 95.4 mg/day, respectively. The estimated 5-year overall survival probability was 61.0%. Initial TKI dose or dose reduction within first year did not affect the overall survival (P = .0571 and .1826, respectively).

CONCLUSION

Dose reduction was observed in 65.9% of the patients at their last visit; except for imatinib, TKI dose densities were < 50% of the recommended dose for the chronic phase. Therefore, the recommended TKI doses might be too high for elderly patients with CML.

Multicentre emergency department study found that paracetamol and ibuprofen were inappropriately used in 83% and 63% of paediatric cases

AIM

The Pain Practice in Italian Paediatric Emergency Departments assessed how appropriately analgesic drugs were being used by Italian clinicians, based on national paediatric pain guidelines.

METHODS

This was a retrospective study that involved 17 Italian members of the Pain In Pediatric Emergency Rooms group. It comprised patients up to the age of 14 years who came to hospital emergency departments with pain and were treated with paracetamol, ibuprofen or opioids, such as codeine, tramadol and morphine.

RESULTS

We studied 1471 patients who were given 1593 doses of analgesics. The median time to administration of analgesia was 25 minutes. Opioids were used in 13.5% of the children, and usage increased with age and with more severe clinical conditions, such as trauma: 1.6% of children under two years, 5.9% aged 3-10 and 8.0% aged 11-14. Inappropriate doses of paracetamol, ibuprofen and opioids were used in 83%, 63% and 33% of cases, respectively. The patient's age was a critical determinant of the correct analgesic dosage; for every one-year increase in the patient's age, the probability of appropriate prescriptions rose 14.8%.

CONCLUSION

The appropriate use of paracetamol and ibuprofen for paediatric pain in Italian emergency departments was very poor, but improved with age.

Clinical factors increasing discrepancies of renal function assessment with MDRD and Cockcroft-Gault equations in old individuals

ABSTRACT

In a daily clinical practice, glomerular filtration rate (GFR) is still estimated on the basis of short MDRD formula, whereas medications' Summaries of Product Characteristics suggest that GFR used for the dosage adjustment should be estimated based on the Cockcroft-Gault (C-G) equation. The aim of the study was to compare eGFR values calculated on the basis of short and full MDRD and C-G equations in PolSenior study participants with decreased eGFR.

METHODS

We have assessed differences in the estimation of GFR between short and full MDRD, as well as C-G formula, all equations utilizing non-isotope-dilution mass spectrometry-calibrated measurements of serum creatinine, in the community-based population of 760 persons aged 65 years or above (mean age 82 ± 8 years) with estimated GFR < 60 ml/min/1.73 m2 (according to short MDRD). In addition, in our analysis, we have included the detailed characteristics of comorbidities and different aspects of mobility and functional performance.

RESULTS

The better concordance, precision, and accuracy with MDRD short formula were found for MDRDfull than C-G equation. In logistic regression analysis, female gender, activities in daily living (ADL) ≤ 4, and age > 80 years diminished, while visceral obesity improved accuracy (P30) of eGFR calculated according to C-G equation as compared to MDRDshort. Similar analysis did not found factors influencing P30 for MDRDfull equation.

CONCLUSIONS

In very old subjects, especially females, dependent patients and those with visceral obesity, estimation of GFR based on short MDRD formula should not be used interchangeably with Cockcroft-Gault equation for the medicines dose tailoring.

Practical Estimation of Ideal Body Weight and Normalized Lean Weight

Simple formulas for estimating ideal body weight (IBW) and normalized lean weight (NLW) are proposed here. The equations are as follows:[Formula: see text][Formula: see text]where W is equal to total patient weight in kilograms and BMI is the body mass index in units of kg/m². The calculated values are equivalent for practical purposes to previously published formulas.

Acamprosate rescues neuronal defects in the Drosophila model of Fragile X Syndrome

AIMS

Several off-label studies have shown that acamprosate can provide some clinical benefits in youth with Fragile X Syndrome (FXS), an autism spectrum disorder caused by loss of function of the highly conserved FMR1 gene. This study investigated the ability of acamprosate to rescue cellular, molecular and behavioral defects in the Drosophila model of FXS.

MAIN METHODS

A high (100μM) and low (10μM) dose of acamprosate was fed to Drosophila FXS (dfmr1 null) or genetic control (w¹¹¹⁸) larvae and then analyzed in multiple paradigms. A larval crawling assay was used to monitor aberrant FXS behavior, overgrowth of the neuromuscular junction (NMJ) was quantified to assess neuronal development, and quantitative RT-PCR was used to evaluate expression of deregulated cbp53E mRNA.

KEY FINDINGS

Acamprosate treatment partially or completely rescued all of the FXS phenotypes analyzed, according to dose. High doses rescued cellular overgrowth and dysregulated cbp53E mRNA expression, but aberrant crawling behavior was not affected. Low doses of acamprosate, however, did not affect synapse number at the NMJ, but could rescue NMJ overgrowth, locomotor defects, and cbp53E mRNA expression. This dual nature of acamprosate suggests multiple molecular mechanisms may be involved in acamprosate function depending on the dosage used.

SIGNIFICANCE

Acamprosate may be a useful therapy for FXS and potentially other autism spectrum disorders. However, understanding the molecular mechanisms involved with different doses of this drug will likely be necessary to obtain optimal results.

Quantitative Intracellular Delivery of Anticancer Nanodrugs Via an Immunoassay Employing Pt-SiO2 Janus-Peroxidase Nanozyme

The accurate and efficient quantification of nanodrug dosage is crucial for early anticancer therapy. The enzyme-linked immunosorbent assay (ELISA) has emerged as a robust tool for detecting anticancer nanodrug dosage; however, the development of sensing elements to quantify anticancer nanodrugs still poses a challenge. To overcome this problem, we utilize polysuccinimide-loaded curcumin (CUR @PSIOAm) as a model to employ an ELISA based on peroxidase nanozyme Pt-SiO2 Janus nanoparticles (Pt-SiO2 JNPs) for the indirect quantitative analysis of intracellular anticancer nanodrug dosage. This novel approach employs an immunoassay to indirectly quantify the dosage of anticancer nanodrugs while preserving its structural integrity. The silica components of Pt-SiO2 JNPs adsorb intermediates, while the Pt NP components exhibit high catalytic activity. Pt-SiO2 JNPs are functionalized with anti-PSIOAm antibody (Pt-SiO2 JNPs-Ab) to serve as an immunosensor capable of specific recognition of CUR @PSIOAm. Additionally, we employed cytotoxicity assays and confocal imaging techniques to demonstrate the excellent biocompatibility of CUR @PSIOAm, as well as its specific uptake by cancer cells. According to the experimental results, the limit of detection (LOD) for the immunoassay of Pt-SiO2 JNPs as a marker for detecting CUR @PSIOAm is approximately 4.5-fold lower than that of horseradish peroxidase. Therefore, by optimizing the conditions, we established a direct competitive ELISA using Pt-SiO2 JNPs as colorimetric indicators for the quantitative detection of intracellular CUR @PSIOAm. The LOD for this ELISA was determined to be 0.01 ng/mL, while the loaded CUR amount calculated from the drug loading capacity was found to be 0.22 pg/mL. Furthermore, the recoveries obtained from this established ELISA ranged between 94.0 and 108%, demonstrating excellent accuracy. Consequently, the peroxidase mimic Pt-SiO2 JNPs-based ELISA exhibits significant potential for precise quantification of intracellular anticancer nanodrug dosages.

[Role of chemotherapy in metastatic castration-resistant prostate cancer (mCRPC) treatment: still standard or exception?]

BACKGROUND

Taxanes have been used as monotherapy for metastatic prostate cancer for two decades.

OBJECTIVES

The current status of docetaxel and cabazitaxel in the treatment sequence for metastatic prostate cancer needs to be clarified.

MATERIALS AND METHODS

Overview of the existing literature regarding approval, dosage and new combination options for metastatic castration-resistant prostate cancer (mCRPC).

RESULTS

Taxanes represent one, but no longer the only treatment option for mCRPC. Previously, monotherapy was standard of care in the first and second line for mCRPC; nowadays taxanes are thrusted in the background due to new encouraging drug options. Based on the promising data of docetaxel in triple therapy setting for hormone-sensitive stage, its role as monotherapy in mCRPC needs to be clarified. Cabazitaxel is an alternative to PSMA radioligand therapy after failure of novel hormonal therapy (NHT) and docetaxel. Therapy adherence for taxanes can be significantly improved by dosage adjustments. Both treatment-related neuroendocrine prostate cancer (t-NEPC) and aggressive variant of prostate cancer (AVPC) represent a challenge for experienced uro-oncologists. Here, the combination of taxane plus platinum represents a promising option.

CONCLUSIONS

Taxanes are indicated in different stages of metastatic prostate cancer. Their use, particularly in combination with other drugs, appears to be promising. Traditional sequential taxane monotherapy regimens will be challenged by novel systemic therapy approaches.

Comparative evaluation of artificial intelligence systems' accuracy in providing medical drug dosages: A methodological study

BACKGROUND

Medication errors, especially in dosage calculation, pose risks in healthcare. Artificial intelligence (AI) systems like ChatGPT and Google Bard may help reduce errors, but their accuracy in providing medication information remains to be evaluated.

AIM

To evaluate the accuracy of AI systems (ChatGPT 3.5, ChatGPT 4, Google Bard) in providing drug dosage information per Harrison's Principles of Internal Medicine.

METHODS

A set of natural language queries mimicking real-world medical dosage inquiries was presented to the AI systems. Responses were analyzed using a 3-point Likert scale. The analysis, conducted with Python and its libraries, focused on basic statistics, overall system accuracy, and disease-specific and organ system accuracies.

RESULTS

ChatGPT 4 outperformed the other systems, showing the highest rate of correct responses (83.77%) and the best overall weighted accuracy (0.6775). Disease-specific accuracy varied notably across systems, with some diseases being accurately recognized, while others demonstrated significant discrepancies. Organ system accuracy also showed variable results, underscoring system-specific strengths and weaknesses.

CONCLUSION

ChatGPT 4 demonstrates superior reliability in medical dosage information, yet variations across diseases emphasize the need for ongoing improvements. These results highlight AI's potential in aiding healthcare professionals, urging continuous development for dependable accuracy in critical medical situations.

Enhanced predictive validity of integrative models for refractory hyperthyroidism considering baseline and early therapy characteristics: a prospective cohort study

BACKGROUND

A subset of Graves' disease (GD) patients develops refractory hyperthyroidism, posing challenges in treatment decisions. The predictive value of baseline characteristics and early therapy indicators in identifying high risk individuals is an area worth exploration.

METHODS

A prospective cohort study (2018-2022) involved 597 newly diagnosed adult GD patients undergoing methimazole (MMI) treatment. Baseline characteristics and 3-month therapy parameters were utilized to develop predictive models for refractory GD, considering antithyroid drug (ATD) dosage regimens.

RESULTS

Among 346 patients analyzed, 49.7% developed ATD-refractory GD, marked by recurrence and sustained Thyrotropin Receptor Antibody (TRAb) positivity. Key baseline factors, including younger age, Graves' ophthalmopathy (GO), larger goiter size, and higher initial free triiodothyronine (fT3), free thyroxine (fT4), and TRAb levels, were all significantly associated with an increased risk of refractory GD, forming the baseline predictive model (Model A). Subsequent analysis based on MMI cumulative dosage at 3 months resulted in two subgroups: a high cumulative dosage group (average ≥ 20 mg/day) and a medium-low cumulative dosage group (average < 20 mg/day). Absolute values, percentage changes, and cumulative values of thyroid function and autoantibodies at 3 months were analyzed. Two combined predictive models, Model B (high cumulative dosage) and Model C (medium-low cumulative dosage), were developed based on stepwise regression and multivariate analysis, incorporating additional 3-month parameters beyond the baseline. In both groups, these combined models outperformed the baseline model in terms of discriminative ability (measured by AUC), concordance with actual outcomes (66.2% comprehensive improvement), and risk classification accuracy (especially for Class I and II patients with baseline predictive risk < 71%). The reliability of the above models was confirmed through additional analysis using random forests. This study also explored ATD dosage regimens, revealing differences in refractory outcomes between predicted risk groups. However, adjusting MMI dosage after early risk assessment did not conclusively improve the prognosis of refractory GD.

CONCLUSION

Integrating baseline and early therapy characteristics enhances the predictive capability for refractory GD outcomes. The study provides valuable insights into refining risk assessment and guiding personalized treatment decisions for GD patients.