scholarly journals Feasibility of a Fixed-Dose Regimen of Pyrazinamide and Its Impact on Systemic Drug Exposure and Liver Safety in Patients with Tuberculosis

2012 ◽  
Vol 56 (11) ◽  
pp. 5442-5449 ◽  
Author(s):  
Tarjinder Sahota ◽  
Oscar Della Pasqua
Keyword(s):  
Dose Regimen ◽  
Drug Exposure ◽  
Therapeutic Agents ◽  
Fixed Dose ◽  
Population Pharmacokinetic ◽  
Target Exposure ◽  
Systemic Drug Exposure ◽  
The Impact ◽  
Systemic Drug ◽  
Novel Therapeutic

ABSTRACTHistorically, dosing regimens for the treatment of tuberculosis (TB) have been proposed in an empirical manner. Dose selection has often been the result of efficacy trials in which drugs were administered regardless of the magnitude of the effect of demographic factors on drug disposition. This has created challenges for the prescription of fixed-dose combinations with novel therapeutic agents. The objectives of this investigation were to evaluate the impact of body weight on the overall systemic exposure to pyrazinamide (PZA) and to assess whether the use of one fixed dose, without adjustment according to weight, would ensure target exposure and safety requirements across the overall patient population. Using a population pharmacokinetic model, simulation scenarios were explored based on population demographics from clinical trials in TB patients and on historical hepatotoxicity data. The systemic drug exposure (area under the concentration-time curve [AUC]), peak concentrations (the maximum concentration of drug in serum [Cmax]), the time above the MIC (t> MIC), and the risk of hepatotoxicity were evaluated for the current weight-banded regimen and compared to fixed doses under the assumption that pharmacokinetic differences are the primary drivers of toxicity. Evaluation of the standard weight banding reveals that more than 50% of subjects in the weight range of 45 to 55 kg remain below the proposed target exposure to PZA. In contrast, the use of a fixed 1,500-mg dose resulted in a lower proportion of subjects under the target value, with a 0.2% average overall increase in the risk of hepatotoxicity. Our results strongly support the use of a fixed-dose regimen for PZA in coformulation or combination with novel therapeutic agents.

scholarly journals Intrathecal Riluzole for the Treatment of Patients With Amyotrophic Lateral Sclerosis

Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Nicholas M Boulis
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Side Effects ◽  
Oral Administration ◽  
Oral Therapy ◽  
Drug Exposure ◽  
Oral Treatment ◽  
Oral Drug ◽  
Systemic Drug Exposure ◽  
Lateral Sclerosis ◽  
Systemic Drug

Abstract INTRODUCTION Oral riluzole is the only approved treatment known to improve survival in patients with amyotrophic lateral sclerosis (ALS), with modest efficacy and dosing limited by hepatic toxicity and asthenia. We postulated that a continuous intrathecal (IT) delivery of low daily doses of riluzole could elevate spinal cord (SC) concentrations well above those achievable with oral treatment alone, without increasing side-effects. METHODS A 6-wk and a 24-wk GLP study were conducted to evaluate the safety of IT riluzole in purpose-bred hound dogs. Oral riluzole, equivalent to 50 mg BID in humans, was administered in combination with one of 3 IT doses given through continuous infusion. Plasma, SC, and brain concentrations of riluzole were measured, along with assessments of safety and tolerability. RESULTS In the 6-wk study, when combining the oral and IT routes, IT infusion significantly increased SC concentrations well above those achieved with oral drug administration alone, without increasing brain concentrations. All IT doses in combination with oral administration were well tolerated by the animals. In the 6-mo study, the lowest dose used in the 6-wk study was dropped and a higher dose was added. This highest dose of IT riluzole was not tolerated by the dogs and yielded SC and brain concentrations significantly higher than achieved in any of our previous studies. CONCLUSION Continuous IT administration of riluzole when combined with oral administration can increase the SC concentration of riluzole above those achievable with oral therapy, without increasing the risk for adverse events associated with systemic drug exposure or off-target side-effects in the brain. Therefore, IT riluzole infusion when used in conjunction with oral therapy may safely enhance lower motor neuron neuroprotection and improve the survival benefit of the drug through enhanced SC delivery, and, with a careful selection of IT doses, it could be implemented in patients with ALS.

Phase I trial of concurrent intraperitoneal and continuous intravenous infusion of fluorouracil in patients with refractory cancer.

1988 ◽  
Vol 6 (1) ◽  
pp. 158-162 ◽  
Author(s):  
B Reichman ◽  
M Markman ◽  
T Hakes ◽  
N Kemeny ◽  
D Kelsen ◽  
...  
Keyword(s):  
Phase I ◽  
Intravenous Infusion ◽  
Phase I Study ◽  
Clinical Utility ◽  
Phase I Trial ◽  
Drug Exposure ◽  
Continuous Intravenous Infusion ◽  
Future Studies ◽  
Systemic Drug Exposure ◽  
Systemic Drug

In an effort to maximize both local-regional and systemic drug exposure to tumor in the peritoneal cavity, a phase I study was conducted that examined the simultaneous daily intraperitoneal (IP) and continuous intravenous infusion (CVI) of fluorouracil (5-FU) to 32 patients with refractory cancer. IP 5-FU administered at 1,000 mg/d with concurrent 5-FU by CVI at 1,000 mg/m2/d for four consecutive days was well tolerated. One patient with a primary gastrointestinal (GI) malignancy with minimal volume disease experienced a surgically defined complete remission. In theory, this regimen may demonstrate clinical utility as an adjuvant treatment of certain GI malignancies. Future studies are planned in this clinical setting.

scholarly journals Oral Lichenoid Reaction: An Uncommon Side Effect of Rituximab

2019 ◽  
Vol 2019 ◽  
pp. 1-3 ◽  
Author(s):  
Amerigo Giudice ◽  
Francesco Liborio ◽  
Fiorella Averta ◽  
Selene Barone ◽  
Leonzio Fortunato
Keyword(s):  
Side Effect ◽  
Oral Lichen Planus ◽  
Drug Exposure ◽  
B Cell Lymphoma ◽  
Systemic Drug Exposure ◽  
Lichenoid Reactions ◽  
The Right ◽  
Oral Lichen ◽  
Histopathological Result ◽  
Systemic Drug

Oral lichenoid reactions (OLR) can be caused by systemic drug exposure. To the best of our knowledge, this is the second report describing a case of OLR induced by rituximab administration in a patient with a diagnosis of non-Hodgkin B-cell lymphoma. After 5 doses of rituximab, a typical pattern of OLP was identified with bilateral and symmetrical lesions on the buccal mucosa and on the right lingual margin. This temporal relationship suggested a probable association between oral lesions and drug therapy. The clinical diagnosis of a rituximab-induced OLR was confirmed by an incisional biopsy reporting a histopathological result of lichenoid mucositis consistent with oral lichen planus. Because of the increasing use of rituximab, it is necessary to know and recognize this uncommon side effect.

Increased doxorubicin levels in hepatic tumors with reduced systemic drug exposure achieved with complete hepatic venous isolation and extracorporeal chemofiltration

1993 ◽  
Vol 33 (3) ◽  
pp. 251-257 ◽  
Author(s):  
Steven A. Curley ◽  
Diana L. Stone ◽  
George M. Fuhrman ◽  
David C. Hohn ◽  
Zahid H. Siddik ◽  
...  
Keyword(s):  
Drug Exposure ◽  
Hepatic Tumors ◽  
Systemic Drug Exposure ◽  
Systemic Drug

scholarly journals Pharmacokinetics of intravenous sildenafil in children with palliated single ventricle heart defects: effect of elevated hepatic pressures

2015 ◽  
Vol 26 (2) ◽  
pp. 354-362 ◽  
Author(s):  
Kevin D. Hill ◽  
Mario R. Sampson ◽  
Jennifer S. Li ◽  
Robert D. Tunks ◽  
Scott R. Schulman ◽  
...  
Keyword(s):  
Drug Exposure ◽  
Structural Model ◽  
Single Ventricle ◽  
Heart Defects ◽  
Model Development ◽  
Area Under The Curve ◽  
Compartment Model ◽  
Population Pharmacokinetic ◽  
Mixed Effect ◽  
The Impact

AbstractAimsSildenafil is frequently prescribed to children with single ventricle heart defects. These children have unique hepatic physiology with elevated hepatic pressures, which may alter drug pharmacokinetics. We sought to determine the impact of hepatic pressure on sildenafil pharmacokinetics in children with single ventricle heart defects.MethodsA population pharmacokinetic model was developed using data from 20 single ventricle children receiving single-dose intravenous sildenafil during cardiac catheterisation. Non-linear mixed effect modelling was used for model development, and covariate effects were evaluated based on estimated precision and clinical significance.ResultsThe analysis included a median (range) of 4 (2–5) pharmacokinetic samples per child. The final structural model was a two-compartment model for sildenafil with a one-compartment model for des-methyl-sildenafil (active metabolite), with assumed 100% sildenafil to des-methyl-sildenafil conversion. Sildenafil clearance was unaffected by hepatic pressure (clearance=0.62 L/hour/kg); however, clearance of des-methyl-sildenafil (1.94×(hepatic pressure/9)−1.33 L/hour/kg) was predicted to decrease ~7-fold as hepatic pressure increased from 4 to 18 mmHg. Predicted drug exposure was increased by ~1.5-fold in subjects with hepatic pressures ⩾10 versus <10 mmHg (median area under the curve=533 versus 792 µg*h/L).DiscussionElevated hepatic pressure delays clearance of the sildenafil metabolite – des-methyl-sildenafil – and increases drug exposure. We speculate that this results from impaired biliary clearance. Hepatic pressure should be considered when prescribing sildenafil to children. These data demonstrate the importance of pharmacokinetic assessments in patients with unique cardiovascular physiology that may affect drug metabolism.

scholarly journals Symmetrical drug-related intertriginous and flexural exanthema due to clindamycin

2019 ◽  
Vol 12 (8) ◽  
pp. e230077 ◽  
Author(s):  
Virginia Cabrera Hernandez ◽  
Monica Gonzalez Afonso ◽  
Ariel Callero Viera ◽  
Lidon Martin-Fernandez Martin
Keyword(s):  
Drug Exposure ◽  
Systemic Exposure ◽  
Standard Test ◽  
Skin Tests ◽  
Hypersensitivity Response ◽  
Cutaneous Eruption ◽  
Systemic Involvement ◽  
Gold Standard Test ◽  
Systemic Drug Exposure ◽  
Systemic Drug

Systemic drug exposure can produce a skin reaction consisting of symmetrical erythema involving the gluteal and intertriginous areas in the absence of systemic involvement. Symmetrical drug-related intertriginous and flexural exanthema (SDRIFE) occurs after systemic exposure to a drug in which the patient was not previously sensitised, either in the first dose or after several doses. The mechanism of SDRIFE is unknown but is hypothesised to be the result of a delayed hypersensitivity response resulting in a cutaneous eruption some days after the exposure to the drug. The diagnosis should be clinical, based on the history and examination, but skin tests can also be performed to confirm sensitisation. But, as always, the gold-standard test is oral provocation. It is important to know this clinical entity to prevent re-exposure to the responsible allergen in the future.

Effect of complete response pre- and post- autologous stem cell transplantation in multiple myeloma

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 7604-7604
Author(s):  
F. Sayani ◽  
D. Stewart ◽  
L. Kmet ◽  
P. Faris ◽  
M. L. Savoie ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Stem Cell ◽  
Complete Response ◽  
Therapeutic Agents ◽  
Line Treatment ◽  
Front Line ◽  
Response Status ◽  
The Impact ◽  
Novel Therapeutic

7604 Background: The value of achieving a complete response (CR) pre or post high dose therapy and autologous stem cell transplant (HDT-ASCT) in multiple myeloma is still uncertain. Knowing the impact of achieving a CR prior to HDT-ASCT on survival, may lead to the incorporation of novel therapeutic agents into the front line treatment of this disease. The aim of our study was to determine whether achieving a CR before or after HDT-ASCT affects overall survival (OS) in multiple myeloma patients. Methods: We performed a retrospective analysis of 88 consecutive myeloma patients receiving HDT-ASCT at our center from 1993 to 2004. The OS of patients achieving at least 90% reduction in their M-protein, i.e. complete response and very good partial response (CR/VGPR), pre or post HDT-ASCT, was compared to that of patients achieving a partial response or less (<90% reduction in M-protein). OS, defined as the number of months from HDT-ASCT to death or last follow up, was estimated by the Kaplan-Meier method. Response status was evaluated pre and at 100 days post HDT-ASCT. Results: Prior to HDT-ASCT, twenty-two (25%) patients achieved a CR/VGPR. Median follow-up time was 39 months for patients in CR/VGPR and 18 months for non-CR/VGPR group. OS at 5 years was 58% (95% CI: 21%-82%) for patients in CR/VGPR, compared to 69% (95% CI: 51%-81%) for all patients in PR or less prior to stem cell collection. Post HDT-ASCT, 48 (55%) patients achieved a CR/VGPR. Their OS estimate at 5 years was 67% (95% CI: 44%-82%) compared to 71% (95% CI: 27%-92%) for all other patients. Overall, 30% more patients achieved CR/VGPR post HDT-ASCT. However, the survival curves did not differ by response status pre or post HDT-ASCT (log-rank test p=0.58 and 0.57 respectively). Conclusions: Our results suggest that achieving a clinical CR/VGPR pre or post HDT-ASCT does not appear to impact OS. These results might have been influenced by the small sample size and the possible need for a longer follow-up time. A more robust definition of CR at the molecular level, plus the use of novel therapeutic agents in front-line treatment, may better define the impact of achieving CR in multiple myeloma. No significant financial relationships to disclose.

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