scholarly journals Pharmacokinetics/pharmacodynamics of chloroquine and artemisinin-based combination therapy with primaquine

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
André Daher ◽  
Ghait Aljayyoussi ◽  
Dhelio Pereira ◽  
Marcus V. G. Lacerda ◽  
Márcia A. A. Alexandre ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Half Life ◽  
Vivax Malaria ◽  
Drug Exposure ◽  
Area Under The Curve ◽  
Compartmental Analysis ◽  
Normal Activity ◽  
Radical Cure ◽  
Cyp2d6 Activity ◽  
Long Acting

Abstract Background Activation of hypnozoites of vivax malaria causes multiple clinical relapses, which contribute to the Plasmodium vivax burden and continuing transmission. Artemisinin-based combination therapy (ACT) is effective against blood-stage P. vivax but requires co-administration with primaquine to achieve radical cure. The therapeutic efficacy of primaquine depends on the generation of a therapeutically active metabolite via cytochrome P450 2D6 (CYP2D6). Impaired CYP2D6 metabolism has been associated with primaquine treatment failure. This study investigated the association between impaired CYP2D6 genotypes, drug-exposure to the long-acting ACT component (schizonticidal drugs) and tolerance and efficacy. Methods Adult patients with acute vivax malaria were enrolled in a recently completed trial and treated with artesunate–mefloquine, chloroquine or artemether–lumefantrine. All received concomitant primaquine (0.5 mg/kg/day for 7–9 days). The association between efficacy and safety and drug exposure was explored using area-under-the-curve (AUC) and half-life (t1/2) estimates obtained by non-compartmental analysis of the long half-life drugs. Parasite recurrences by day 63 were categorized as related relapses or re-infections/unrelated hypnozoite activation by genotyping three microsatellite loci and two polymorphic loci of merozoite surface antigen-1. The CYP2D6 genotype was identified with Taqman assays by real-time PCR to 9 polymorphisms (8 SNPs and one deletion). Impaired CYP2D6 activity was inferred using the Activity Score System. Results Most recurrences in the ASMQ (67%), CQ (80%) and AL (85%) groups were considered related relapses. Eight of nine (88.9%) of the patients with impaired CYP2D6 activity relapsed with related parasite compared to 18/25 (72%) with normal activity (RR = 1.23, 0.88; 1.72, p = 0.40). There were no associations between the measured PK parameters and recurrence. Patients with longer chloroquine half-lives had more pruritus (RR = 1.09, 1.03; 1.14, p = 0.001). Higher CQ AUCs were associated with reduced falls in haemoglobin by day 14 (Coef − 0.02, − 0.005; − 0.03, p = 0.01). All regimens were well tolerated. Conclusion Genotyping of P. vivax showed that activation of related (homologous) hypnozoites was the most frequent cause of recurrence. The high proportion of the impaired CYP2D6 activity among patients with recurrent infections suggests that slow primaquine metabolism might influence related relapse rates in Brazil among patients receiving primaquine for radical cure, although confirmatory studies are needed. There was no association between drug exposure of the long-acting ACT component (schizonticidal drugs) and risk of related relapse. ACT was well tolerated. These results provide further re-assurance about the safety and efficacy of ACT when combined with short course primaquine to treat uncomplicated malaria vivax in Brazil. Trial registration RBR-79s56s (http://www.ensaiosclinicos.gov.br/rg/RBR-79s56s/)

scholarly journals Effect of tablet crushing on drug exposure in the treatment of multidrug-resistant tuberculosis

2019 ◽  
Vol 23 (10) ◽  
pp. 1068-1074 ◽  
Author(s):  
R. Court ◽  
M. T. Chirehwa ◽  
L. Wiesner ◽  
N. de Vries ◽  
J. Harding ◽  
...  
Keyword(s):  
Drug Exposure ◽  
Geometric Mean ◽  
Area Under The Curve ◽  
Compartmental Analysis ◽  
Multidrug Resistant ◽  
Geometric Mean Ratio ◽  
Tb Treatment ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Mdr Tb

SETTING: Treatment outcomes in multidrug-resistant tuberculosis (MDR-TB) are poor. Due to drug toxicity and a long treatment duration, approximately half of patients are treated successfully. Medication is often crushed for patients who have difficulty swallowing whole tablets. Whether crushing tablets affects drug exposure in MDR-TB treatment is not known.OBJECTIVE AND DESIGN: We performed a sequential pharmacokinetic study in patients aged >18 years on MDR-TB treatment at two hospitals in Cape Town, South Africa. We compared the bioavailability of pyrazinamide, moxifloxacin, isoniazid (INH), ethambutol and terizidone when the tablets were crushed and mixed with water before administration vs. swallowed whole. We sampled blood at six time points over 10 h under each condition separated by 2 weeks. Non-compartmental analysis was used to derive the key pharmacokinetic measurements.RESULTS: Twenty participants completed the study: 15 were men, and the median age was 31.5 years. There was a 42% reduction in the area under the curve AUC0–10 of INH when the tablets were crushed compared with whole tablets (geometric mean ratio 58%; 90%CI 47–73). Crushing tablets of pyrazinamide, moxifloxacin, ethambutol and terizidone did not affect the bioavailability significantly.CONCLUSION: We recommend that crushing of INH tablets in the MDR-TB treatment regimen be avoided. Paediatric INH formulations may be a viable alternative if the crushing of INH tablets is indicated.

scholarly journals Which Analysis Approach Is Adequate to Leverage Clinical Microdialysis Data? A Quantitative Comparison to Investigate Exposure and Reponse Exemplified by Levofloxacin

2021 ◽  
Author(s):  
David Busse ◽  
André Schaeftlein ◽  
Alexander Solms ◽  
Luis Ilia ◽  
Robin Michelet ◽  
...  
Keyword(s):  
Drug Exposure ◽  
Visual Predictive Check ◽  
Model Performance ◽  
Compartmental Analysis ◽  
Community Acquired Pneumonia ◽  
Target Site ◽  
Clinical Pharmacokinetics ◽  
Time Integral ◽  
Dosing Regimens ◽  
Therapeutic Decision Making

Abstract Purpose Systematic comparison of analysis methods of clinical microdialysis data for impact on target-site drug exposure and response. Methods 39 individuals received a 500 mg levofloxacin short-term infusion followed by 24-h dense sampling in plasma and microdialysate collection in interstitial space fluid (ISF). ISF concentrations were leveraged using non-compartmental (NCA) and compartmental analysis (CA) via (ii) relative recovery correction at midpoint of the collection interval (midpoint-NCA, midpoint-CA) and (ii) dialysate-based integrals of time (integral-CA). Exposure and adequacy of community-acquired pneumonia (CAP) therapy via pharmacokinetic/pharmacodynamic target-attainment (PTA) analysis were compared between approaches. Results Individual AUCISF estimates strongly varied for midpoint-NCA and midpoint-CA (≥52.3%CV) versus integral-CA (≤32.9%CV) owing to separation of variability in PK parameters (midpoint-CA = 46.5%–143%CVPK, integral-CA = 26.4%–72.6%CVPK) from recovery-related variability only in integral-CA (41.0%–50.3%CVrecovery). This also led to increased variability of AUCplasma for midpoint-CA (56.0%CV) versus midpoint-NCA and integral-CA (≤33.0%CV), and inaccuracy of predictive model performance of midpoint-CA in plasma (visual predictive check). PTA analysis translated into 33% of evaluated patient cases being at risk of incorrectly rejecting recommended dosing regimens at CAP-related epidemiological cut-off values. Conclusions Integral-CA proved most appropriate to characterise clinical pharmacokinetics- and microdialysis-related variability. Employing this knowledge will improve the understanding of drug target-site PK for therapeutic decision-making.

scholarly journals Triple versus LAMA/LABA combination therapy for patients with COPD: a systematic review and meta-analysis

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Akira Koarai ◽  
Mitsuhiro Yamada ◽  
Tomohiro Ichikawa ◽  
Naoya Fujino ◽  
Tomotaka Kawayama ◽  
...  
Keyword(s):  
Systematic Review ◽  
Combination Therapy ◽  
Triple Therapy ◽  
Odds Ratio ◽  
Controlled Trial ◽  
Meta Analysis ◽  
Beta Agonist ◽  
History Of ◽  
Dyspnea Score ◽  
Long Acting

Abstract Background Recently, the addition of inhaled corticosteroid (ICS) to long-acting muscarinic antagonist (LAMA) and long-acting beta-agonist (LABA) combination therapy has been recommended for patients with COPD who have severe symptoms and a history of exacerbations because it reduces the exacerbations. In addition, a reducing effect on mortality has been shown by this treatment. However, the evidence is mainly based on one large randomized controlled trial IMPACT study, and it remains unclear whether the ICS add-on treatment is beneficial or not. Recently, a large new ETHOS trial has been performed to clarify the ICS add-on effects. Therefore, we conducted a systematic review and meta-analysis to evaluate the efficacy and safety including ETHOS trial. Methods We searched relevant randomized control trials (RCTs) and analyzed the exacerbations, quality of life (QOL), dyspnea symptom, lung function and adverse events including pneumonia and mortality, as the outcomes of interest. Results We identified a total of 6 RCTs in ICS add-on protocol (N = 13,579). ICS/LAMA/LABA treatment (triple therapy) significantly decreased the incidence of exacerbations (rate ratio 0.73, 95% CI 0.64–0.83) and improved the QOL score and trough FEV1 compared to LAMA/LABA. In addition, triple therapy significantly improved the dyspnea score (mean difference 0.33, 95% CI 0.18–0.48) and mortality (odds ratio 0.66, 95% CI 0.50–0.87). However, triple therapy showed a significantly higher incidence of pneumonia (odds ratio 1.52, 95% CI 1.16–2.00). In the ICS-withdrawal protocol including 2 RCTs, triple therapy also showed a significantly better QOL score and higher trough FEV1 than LAMA/LABA. Concerning the trough FEV1, QOL score and dyspnea score in both protocols, the differences were less than the minimal clinically important difference. Conclusion Triple therapy causes a higher incidence of pneumonia but is a more preferable treatment than LAMA/LABA due to the lower incidence of exacerbations, higher trough FEV1 and better QOL score. In addition, triple therapy is also superior to LABA/LAMA due to the lower mortality and better dyspnea score. However, these results should be only applied to patients with symptomatic moderate to severe COPD and a history of exacerbations. Clinical Trial Registration: PROSPERO; CRD42020191978.

Phase I Dose-Finding Study of Weekly Single-Agent Patupilone in Patients With Advanced Solid Tumors

2005 ◽  
Vol 23 (36) ◽  
pp. 9120-9129 ◽  
Author(s):  
Eric H. Rubin ◽  
John Rothermel ◽  
Fisseha Tesfaye ◽  
Tianling Chen ◽  
Martine Hubert ◽  
...  
Keyword(s):  
Partial Response ◽  
Solid Tumors ◽  
Half Life ◽  
Drug Exposure ◽  
Dose Range ◽  
Single Agent ◽  
Dose Finding ◽  
Advanced Solid Tumors ◽  
Blood Concentrations ◽  
Terminal Half Life

Purpose To evaluate the safety and maximum-tolerated dose (MTD) of weekly patupilone, a natural epothilone B, in patients with advanced solid tumors. Patients and Methods Patients were treated with patupilone (0.3 to 3.6 mg/m2) for 6 weeks on/3 weeks off or 3 weeks on/1 week off. Dose-limiting toxicities (DLTs), MTD, and pharmacokinetics were determined for each schedule of administration. Results Ninety-one patients were enrolled. The most common tumor types included ovarian, breast, and colon cancers. Doses of patupilone less than 2.5 mg/m2 using either the 6 weeks on/3 weeks off or the 3 weeks on/1 week off schedule were tolerated well. At higher doses, DLTs were observed using both dosing schedules, with diarrhea the most common DLT. The MTD for both treatment schedules was 2.5 mg/m2. After a short infusion, patupilone blood concentrations declined in a multiphasic manner with a terminal half-life of 4 days. Drug clearance was nonrenal and was not related to body-surface area. Over the dose range evaluated, systemic drug exposure was approximately dose proportional. Three patients achieved a partial response, and 31 patients had stable disease. Two patients experiencing a partial response had received prior taxane therapy. Conclusion Patupilone is well tolerated when administered at a dose of 2.5 mg/m2, using either a 6 weeks on/3 weeks off or a 3 weeks on/1 week off schedule. In contrast with murine studies, patupilone has a relatively prolonged terminal half-life in humans. The partial responses in patients previously treated with taxanes is consistent with promising preclinical results.

scholarly journals PK/PD Analysis of Marbofloxacin by Monte Carlo Simulation against Mycoplasma agalactiae in Plasma and Milk of Lactating Goats after IV, SC and SC-Long Acting Formulations Administration

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1104
Author(s):  
Emilio Fernández-Varón ◽  
Edgar García-Romero ◽  
Juan M. Serrano-Rodríguez ◽  
Carlos M. Cárceles ◽  
Ana García-Galán ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
High Performance ◽  
Small Ruminants ◽  
Area Under The Curve ◽  
Hplc Method ◽  
Surrogate Markers ◽  
Contagious Agalactia ◽  
Lactating Goats ◽  
Long Acting

Contagious agalactia is a mycoplasmosis affecting small ruminants that have become an important issue in many countries. However, PK/PD studies of antibiotics to treat this problem in lactating goats affected by Mycoplasma (M.) agalactiae, the main CA-causing mycoplasma are almost non-existent. The aims of this study were to evaluate the plasma and milk disposition of marbofloxacin in lactating goats after intravenous (IV), subcutaneous (SC) and subcutaneous poloxamer P407 formulations with and without carboxy-methylcellulose (SC-P407-CMC and SC-P407) administration. Marbofloxacin concentrations were analysed by the High Performance Liquid Chromatography (HPLC) method. Minimum inhibitory concentrations (MIC) of M. agalactiae field isolates from mastitic goat’s milk were used to calculate surrogate markers of efficacy. Terminal half-lives of marbofloxacin after IV, SC, SC-P407 and SC-P407-CMC administration were 7.12, 6.57, 13.92 and 12.19 h in plasma, and the half-lives of elimination of marbofloxacin in milk were 7.22, 7.16, 9.30 and 7.74 h after IV, SC, SC-P407 and SC-P407-CMC administration, respectively. Marbofloxacin penetration from the blood into the milk was extensive, with Area Under the Curve (AUCmilk/AUCplasma) ratios ranged 1.04–1.23, and maximum concentrations (Cmax-milk/Cmax-plasma) ratios ranged 0.72–1.20. The PK/PD surrogate markers of efficacy fAUC24/MIC and the Monte Carlo simulation show that marbofloxacin ratio (fAUC24/MIC > 125) using a 90% of target attainment rate (TAR) need a dose regimen between 8.4 mg/kg (SC) and 11.57 mg/kg (P407CMC) and should be adequate to treat contagious agalactia in lactating goats.

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