scholarly journals Comparative Performances of Flubendazole and Albendazole in Cystic Echinococcosis:Ex VivoActivity, Plasma/Cyst Disposition, and Efficacy in Infected Mice

2011 ◽  
Vol 55 (12) ◽  
pp. 5861-5867 ◽  
Author(s):  
Laura Ceballos ◽  
Celina Elissondo ◽  
Sergio Sánchez Bruni ◽  
Guillermo Denegri ◽  
Carlos Lanusse ◽  
...  

ABSTRACTThe need to identify improved therapy against cystic echinococcosis (CE) has motivated pharmacology-based research. The comparative pharmacological performances of the benzimidazole compounds flubendazole (FLBZ) and albendazole (ABZ) were addressed here. The goals of the work were as follows: (i) to evaluate theex vivoactivities of FLBZ, ABZ, and their respective metabolites againstEchinococcus granulosusprotoscoleces, (ii) to compare the plasma and cyst disposition kinetics for the two drugs in infected mice, and (iii) to compare the clinical efficacies of FLBZ and ABZ against CE in mice. For theex vivostudy,E. granulosusprotoscoleces were incubated with FLBZ, reduced FLBZ (R-FLBZ), ABZ, and ABZ-sulfoxide (ABZSO) (10 nmol/ml). Protoscolex viability was monitored by the methylene blue exclusion test and scanning electron microscopy (SEM). For the pharmacokinetic study, BALB/c mice with CE were allocated to two different groups and orally treated with either FLBZ or ABZ (5 mg/kg of body weight), both formulated as a cyclodextrin-based solution. Blood and cyst samples were taken up to 12 h posttreatment and analyzed by high-performance liquid chromatography (HPLC). For the efficacy study, CE-infected BALB/c mice were divided into three groups: the unmedicated control group and the FLBZ- and ABZ-treated groups. Oral treatments were performed twice a day during 25 days. After treatment, all animals were killed and the weight of the cysts was recorded. Loss of protoscolex viability was observed after drug incubation. FLBZ was detected in plasma (area under the concentration-versus-time curve [AUC] = 1.8 μg·h/ml) and cysts (AUC = 0.3 μg·h/g) collected from treated infected animals. Conversely, ABZSO was the only active molecule measured in plasma (AUC = 4.4 μg·h/ml) and cysts (AUC = 1.5 μg·h/g) after ABZ treatment. FLBZ induced a 90% reduction in cyst weight in comparison to those collected from untreated control mice (P< 0.05). However, no differences in cyst weight were observed between the ABZ-treated (8.2 g) and unmedicated control (10.5 g) groups. Due to these results, we consider flubendazole to have great potential to become a drug of choice in the treatment of cystic echinococcosis.

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Elizabeth A. Lakota ◽  
Justin C. Bader ◽  
Voon Ong ◽  
Ken Bartizal ◽  
Lynn Miesel ◽  
...  

ABSTRACT CD101 is a novel echinocandin with concentration-dependent fungicidal activity in vitro and a long half-life (∼133 h in humans, ∼70 to 80 h in mice). Given these characteristics, it is likely that the shape of the CD101 exposure (i.e., the time course of CD101 concentrations) influences efficacy. To test this hypothesis, doses which produce the same total area under the concentration-time curve (AUC) were administered to groups of neutropenic ICR mice infected with Candida albicans R303 using three different schedules. A total CD101 dose of 2 mg/kg was administered as a single intravenous (i.v.) dose or in equal divided doses of either 1 mg/kg twice weekly or 0.29 mg/kg/day over 7 days. The studies were performed using a murine disseminated candidiasis model. Animals were euthanized at 168 h following the start of treatment. Fungi grew well in the no-treatment control group and showed variable changes in fungal density in the treatment groups. When the CD101 AUC from 0 to 168 h (AUC0–168) was administered as a single dose, a >2 log10 CFU reduction from the baseline at 168 h was observed. When twice-weekly and daily regimens with similar AUC values were administered, net fungal stasis and a >1 log10 CFU increase from the baseline were observed, respectively. These data support the hypothesis that the shape of the CD101 AUC influences efficacy. Thus, CD101 administered once per week demonstrated a greater degree of fungal killing than the same dose divided into twice-weekly or daily regimens.


2020 ◽  
Vol 64 (7) ◽  
Author(s):  
Anne C. G. Almeida ◽  
Maria C. B. Puça ◽  
Erick F. G. Figueiredo ◽  
Laila R. Barbosa ◽  
Yanka E. A. R. Salazar ◽  
...  

ABSTRACT Cytochrome P450 (CYP) enzymes are involved in the biotransformation of chloroquine (CQ), but the role of the different profiles of metabolism of this drug in relation to Plasmodium vivax recurrences has not been properly investigated. To investigate the influence of the CYP genotypes associated with CQ metabolism on the rates of P. vivax early recurrences, a case-control study was carried out. The cases included patients presenting with an early recurrence (CQ-recurrent individuals), defined as a recurrence during the first 28 days after initial infection and plasma concentrations of CQ plus desethylchloroquine (DCQ; the major CQ metabolite) higher than 100 ng/ml. A control group with no parasite recurrence over the follow-up (the CQ-responsive group) was also included. CQ and DCQ plasma levels were measured on day 28. CQ-metabolizing CYP (CYP2C8, CYP3A4, and CYP3A5) genotypes were determined by real-time PCR. An ex vivo study was conducted to verify the efficacy of CQ and DCQ against P. vivax isolates. The frequency of alleles associated with normal and slow metabolism was similar between the cases and the controls for the CYP2C8 (odds ratio [OR] = 1.45, 95% confidence interval [CI] = 0.51 to 4.14, P = 0.570), CYP3A4 (OR = 2.38, 95% CI = 0.92 to 6.19, P = 0.105), and CYP3A5 (OR = 4.17, 95% CI = 0.79 to 22.04, P = 1.038) genes. DCQ levels were higher than CQ levels, regardless of the genotype. Regarding the DCQ/CQ ratio, there was no difference between groups or between those patients who had a normal genotype and those patients who had a mutant genotype. DCQ and CQ showed similar efficacy ex vivo. CYP genotypes had no influence on early recurrence rates. The similar efficacy of CQ and DCQ ex vivo could explain the absence of therapeutic failure, despite the presence of alleles associated with slow metabolism.


2015 ◽  
Vol 59 (7) ◽  
pp. 4260-4271 ◽  
Author(s):  
John M. Benjamin ◽  
Brioni R. Moore ◽  
Sam Salman ◽  
Madhu Page-Sharp ◽  
Somoyang Tawat ◽  
...  

ABSTRACTThe tolerability, safety, and disposition of dihydroartemisinin (DHA) and piperaquine (PQ) were assessed in 32 pregnant (second/third trimester) and 33 nonpregnant Papua New Guinean women randomized to adult treatment courses of DHA-PQ (three daily doses) or sulfadoxine-pyrimethamine (SP)-PQ (three daily PQ doses, single dose of SP). All dose adminstrations were observed, and subjects fasted for 2 h postdose. Plasma PQ was assayed by using high-performance liquid chromatography, and DHA was assessed by using liquid chromatography-mass spectrometry. Compartmental pharmacokinetic models were developed using a population-based approach. Both regimens were well tolerated. There was an expected increase in the rate-corrected electrocardiographic QT interval which was independent of pregnancy and treatment. Two pregnant and two nonpregnant women hadPlasmodium falciparumparasitemia which cleared within 48 h, and no other subject became slide positive for malaria during 42 days of follow-up. Of 30 pregnant women followed to delivery, 27 (90%) delivered healthy babies and 3 (10%) had stillbirths; these obstetric outcomes are consistent with those in the general population. The area under the plasma PQ concentration-time curve (AUC0–∞) was lower in the pregnant patients (median [interquartile range], 23,721 μg · h/liter [21,481 to 27,951 μg · h/liter] versus 35,644 μg · h/liter [29,546 to 39,541 μg · h/liter];P< 0.001) in association with a greater clearance relative to bioavailability (73.5 liters/h [69.4 to 78.4] versus 53.8 liters/h [49.7 to 58.2];P< 0.001), but pregnancy did not influence the pharmacokinetics of DHA. The apparent pharmacokinetic differences between the present study and results from other studies of women with uncomplicated malaria that showed no effect of pregnancy on the AUC0–∞of PQ and greater bioavailability may reflect differences in postdose fat intake, proportions of women with malaria, and/or racial differences in drug disposition.


2015 ◽  
Vol 59 (9) ◽  
pp. 5768-5774 ◽  
Author(s):  
Vincent P. DeMarco ◽  
Alvaro A. Ordonez ◽  
Mariah Klunk ◽  
Brendan Prideaux ◽  
Hui Wang ◽  
...  

ABSTRACTInformation about intralesional pharmacokinetics (PK) and spatial distribution of tuberculosis (TB) drugs is limited and has not been used to optimize dosing recommendations for new or existing drugs. While new techniques can detect drugs and their metabolites within TB granulomas, they are invasive, rely on accurate resection of tissues, and do not capture dynamic drug distribution in the tissues of interest. In this study, we assessed thein situdistribution of11C-labeled rifampin in live,Mycobacterium tuberculosis-infected mice that develop necrotic lesions akin to human disease. Dynamic positron emission tomography (PET) imaging was performed over 60 min after injection of [11C]rifampin as a microdose, standardized uptake values (SUV) were calculated, and noncompartmental analysis was used to estimate PK parameters in compartments of interest. [11C]rifampin was rapidly distributed to all parts of the body and quickly localized to the liver. Areas under the concentration-time curve for the first 60 min (AUC0–60) in infected and uninfected mice were similar for liver, blood, and brain compartments (P> 0.53) and were uniformly low in brain (10 to 20% of blood values). However, lower concentrations were noted in necrotic lung tissues of infected mice than in healthy lungs (P= 0.03).Ex vivotwo-dimensional matrix-assisted laser desorption ionization (MALDI) imaging confirmed restricted penetration of rifampin into necrotic lung lesions. Noninvasive bioimaging can be used to assess the distribution of drugs into compartments of interest, with potential applications for TB drug regimen development.


2012 ◽  
Vol 56 (4) ◽  
pp. 1762-1768 ◽  
Author(s):  
Wai Kit Chew ◽  
Ignacio Segarra ◽  
Stephen Ambu ◽  
Joon Wah Mak

ABSTRACTToxoplasma gondiiis a parasite that generates latent cysts in the brain; reactivation of these cysts may lead to fatal toxoplasmic encephalitis, for which treatment remains unsuccessful. We assessed spiramycin pharmacokinetics coadministered with metronidazole, the eradication of brain cysts and thein vitroreactivation. Male BALB/c mice were fed 1,000 tachyzoites orally to develop chronic toxoplasmosis. Four weeks later, infected mice underwent different treatments: (i) infected untreated mice (n= 9), which received vehicle only; (ii) a spiramycin-only group (n= 9), 400 mg/kg daily for 7 days; (iii) a metronidazole-only group (n= 9), 500 mg/kg daily for 7 days; and (iv) a combination group (n= 9), which received both spiramycin (400 mg/kg) and metronidazole (500 mg/kg) daily for 7 days. An uninfected control group (n= 10) was administered vehicle only. After treatment, the brain cysts were counted, brain homogenates were cultured in confluent Vero cells, and cysts and tachyzoites were counted after 1 week. Separately, pharmacokinetic profiles (plasma and brain) were assessed after a single dose of spiramycin (400 mg/kg), metronidazole (500 mg/kg), or both. Metronidazole treatment increased the brain spiramycin area under the concentration-time curve from 0 h to ∞ (AUC0–∞) by 67% without affecting its plasma disposition. Metronidazole plasma and brain AUC0–∞values were reduced 9 and 62%, respectively, after spiramycin coadministration. Enhanced spiramycin brain exposure after coadministration reduced brain cysts 15-fold (79 ± 23 for the combination treatment versus 1,198 ± 153 for the untreated control group [P< 0.05]) and 10-fold versus the spiramycin-only group (768 ± 125). Metronidazole alone showed no effect (1,028 ± 149). Tachyzoites were absent in the brain. Spiramycin reducedin vitroreactivation. Metronidazole increased spiramycin brain penetration, causing a significant reduction ofT. gondiibrain cysts, with potential clinical translatability for chronic toxoplasmosis treatment.


2003 ◽  
Vol 13 (1) ◽  
pp. 29-31
Author(s):  
R. Kingston ◽  
J. Noël ◽  
B. Murphy ◽  
T. C Lee ◽  
M.G. Walsh

Dall-Miles cables are widely used for trochanteric re-attachment in hip arthroplasty, but their effects on the cement mantle have not been reported. We have carried out an ex vivo study to investigate the influence of cables on the mantle. Charnley femoral components were implanted in eight proximal human femora using Palacos cement. Wires (control group, n=4) or 2mm stainless steel Dall-Miles cables (n=4) were passed through holes drilled in the proximal femur before the cement was introduced. The wires or cables were tightened using the appropriate instruments after the cement had hardened. The specimens were sectioned using a diamond saw, and examined by scanning electron microscopy and light microscopy before and after staining with penetrant dye. Deformation of the strands at the tension edge of each cable, with debonding from the cement in two specimens, was observed. There was no damage to cement at the compression edge. Tensioning of Dall-Miles cables passing through Palacos cement does not appear to damage the mantle.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 539
Author(s):  
Sean N. Avedissian ◽  
Michelle Pham ◽  
Medha D. Joshi ◽  
Marc H. Scheetz ◽  
Ashkan Salamatipour ◽  
...  

While the antiarrhythmic drug amiodarone is commonly used in clinical practice, it has a narrow therapeutic index that can lead to acute overdose. One proposed method to deal with this toxicity is lipid emulsion therapy, which may potentially quench the free amiodarone in blood and prevent its further distribution to target organs and tissues. In this study, we utilize an established swine model to examine the effects of Intralipid™ (IL) administration for acute amiodarone toxicity. A total of 14 pigs received an overdose of intravenous amiodarone. After twenty minutes, half of the pigs (n = 7) received IL while the control group (n = 7) received normal saline. Serum concentrations of amiodarone were then analyzed using a validated high-performance liquid chromatography (HPLC) method. Noncompartmental pharmacokinetic analyses were performed on the observed concentrations. There were no statistical differences in the area under the concentration time curve (6 h) or clearance, but there was a difference in the half-life between the two groups (3.12 vs. 0.85 h, p = 0.01). The administration of IL did not statistically change the overall exposure of amiodarone in the blood in the first 6 h; however, trends toward prolonged blood retention in the IL group were seen.


2013 ◽  
Vol 57 (6) ◽  
pp. 2793-2800 ◽  
Author(s):  
Ajay Sudan ◽  
Joanne Livermore ◽  
Susan J. Howard ◽  
Zaid Al-Nakeeb ◽  
Andrew Sharp ◽  
...  

ABSTRACTFluconazole is frequently the only antifungal agent that is available for induction therapy for cryptococcal meningitis. There is relatively little understanding of the pharmacokinetics and pharmacodynamics (PK-PD) of fluconazole in this setting. PK-PD relationships were estimated with 4 clinical isolates ofCryptococcus neoformans. MICs were determined using Clinical and Laboratory Standards Institute (CLSI) methodology. A nonimmunosuppressed murine model of cryptococcal meningitis was used. Mice received two different doses of fluconazole (125 mg/kg of body weight/day and 250 mg/kg of body weight/day) orally for 9 days; a control group of mice was not given fluconazole. Fluconazole concentrations in plasma and in the cerebrum were determined using high-performance liquid chromatography (HPLC). The cryptococcal density in the brain was estimated using quantitative cultures. A mathematical model was fitted to the PK-PD data. The experimental results were extrapolated to humans (bridging study). The PK were linear. A dose-dependent decline in fungal burden was observed, with near-maximal activity evident with dosages of 250 mg/kg/day. The MIC was important for understanding the exposure-response relationships. The mean AUC/MIC ratio associated with stasis was 389. The results of the bridging study suggested that only 66.7% of patients receiving 1,200 mg/kg would achieve or exceed an AUC/MIC ratio of 389. The potential breakpoints for fluconazole againstCryptococcus neoformansfollow: susceptible, ≤2 mg/liter; resistant, >2 mg/liter. Fluconazole may be an inferior agent for induction therapy because many patients cannot achieve the pharmacodynamic target. Clinical breakpoints are likely to be significantly lower than epidemiological cutoff values. The MIC may guide the appropriate use of fluconazole. If fluconazole is the only option for induction therapy, then the highest possible dose should be used.


2012 ◽  
Vol 56 (10) ◽  
pp. 5328-5331 ◽  
Author(s):  
José Moltó ◽  
Marta Valle ◽  
Cristina Miranda ◽  
Samandhy Cedeño ◽  
Eugenia Negredo ◽  
...  

ABSTRACTThe aim of this open-label, fixed-sequence study was to investigate the potential of the botanical supplementEchinacea purpureato interact with etravirine, a nonnucleoside reverse transcriptase inhibitor of HIV. Fifteen HIV-infected patients receiving antiretroviral therapy with etravirine (400 mg once daily) for at least 4 weeks were included.E. purpurearoot/extract-containing capsules were added to the antiretroviral treatment (500 mg every 8 h) for 14 days. Etravirine concentrations in plasma were determined by high-performance liquid chromatography immediately before and 1, 2, 4, 6, 8, 10, 12, and 24 h after a morning dose of etravirine on day 0 and etravirine plusE. purpureaon day 14. Individual etravirine pharmacokinetic parameters were calculated by noncompartmental analysis and compared between days 0 and 14 by means of the geometric mean ratio (GMR) and its 90% confidence interval (CI). The median age was 46 years (interquartile range, 41 to 50), and the median body weight was 76 kg (interquartile range, 68 to 92). Echinacea was well tolerated, and all participants completed the study. The GMR for etravirine coadministered withE. purpurearelative to etravirine alone was 1.07 (90% CI, 0.81 to 1.42) for the maximum concentration, 1.04 (90% CI, 0.79 to 1.38) for the area under the concentration-time curve from 0 to 24 h, and 1.04 (90% CI, 0.74 to 1.44) for the concentration at the end of the dosing interval. In conclusion, the coadministration ofE. purpureawith etravirine was safe and well tolerated in HIV-infected patients; our data suggest that no dose adjustment for etravirine is necessary.


2012 ◽  
Vol 56 (5) ◽  
pp. 2435-2442 ◽  
Author(s):  
Maiken Cavling Arendrup ◽  
David S. Perlin ◽  
Rasmus Hare Jensen ◽  
Susan Julie Howard ◽  
Joanne Goodwin ◽  
...  

ABSTRACTWe recently observed that the micafungin MICs for someCandida glabrata fkshot spot mutant isolates are less elevated than those for the other echinocandins, suggesting that the efficacy of micafungin may be differentially dependent on such mutations. Three clinicalC. glabrataisolates with or without (S3)fkshot spot mutations R83 (Fks2p-S663F) and RR24 (Fks1p-S629P) and low, medium, and high echinocandin MICs, respectively, were evaluated to assess thein vivoefficacy in an immunocompetent mouse model using three doses of each echinocandin. Drug concentrations were determined in plasma and kidneys by high-performance liquid chromatography (HPLC). A pharmacokinetic-pharmacodynamic mathematical model was used to define the area under the concentration-time curve (AUC) that produced half- and near-maximal activity. Micafungin was equally efficacious against the S3 and R83 isolates. The estimates for the AUCs of each echinocandin that induced half-maximal effect (E50s) were 194.2 and 53.99 mg · h/liter, respectively. In contrast, the maximum effect (Emax) for caspofungin was higher against S3 than R83, but the estimates for E50were similar (187.1 and 203.5 mg · h/liter, respectively). Anidulafungin failed to induce a ≥1-log reduction for any of the isolates (AUC range, 139 to 557 mg · h/liter). None of the echinocandins were efficacious in mice challenged with the RR24 isolate despite lower virulence (reduced maximal growth, prolonged lag phase, and lower kidney burden). The AUC associated with half-maximal effect was higher than the average human exposure for all drug-dose-bug combinations except micafungin and the R83 isolate. In conclusion, differences in micafungin MICs are associated with differential antifungal activities in the animal model. This study may have implications for clinical practice and echinocandin breakpoint determination, and further studies are warranted.


Sign in / Sign up

Export Citation Format

Share Document