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In the mid 1990s, researchers began to investigate the antiangiogenic activity of paclitaxel as a possible additional mechanism contributing to its antineoplastic activity in vivo. In the last decade, a number of studies showed that paclitaxel has antiangiogenic activity that could be ascribed to the inhibition of either tubule formation or cell migration, and to an antiproliferative effect towards activated endothelial cells. Furthermore, paclitaxel was shown to downregulate VEGF and Ang-1 expression in tumor cells, and to increase the secretion of TSP-1 in the tumor microenvironment. Moreover, the new pharmaceutical formulations of paclitaxel (such as liposome-encapsulated paclitaxel, ABI-007, and paclitaxel entrapped in emulsifying wax nanoparticles) enhanced the in vivo antiangiogenic activity of the drug. Thus, the preclinical data of paclitaxel may be exploited to implement a novel and rational therapeutic strategy to control tumor progression in patients.

In the past 20 years, an increased discrepancy between new available antibacterials and the emergence of multidrug-resistant strains has been observed. This condition concerns physicians involved in the treatment of central nervous system (CNS) infections, for which clinical and microbiological success depends on the rapid achievement of bactericidal concentrations. In order to accomplish this aim, the choice of drugs is based on their disposition toward the cerebrospinal fluid (CSF), which is influenced by the physicochemical characteristics of antibacterials. A reduced distribution into CSF has been documented for beta-lactams, especially cephalosporins and carbapenems, on the basis of their hydrophilic nature. However, they represent a cornerstone of the majority of combined therapeutic schemes for their ability to achieve bactericidal concentrations, especially in the presence of inflamed meninges. The good tolerability of beta-lactams makes possible high daily dose intensities, which may be associated with increased probability of cure. Furthermore, the adoption of continuous infusion seems to be a fruitful option. Fluoroquinolones, namely moxifloxacin, and antituberculosis drugs, together with the agents such as linezolid, reach the highest CSF/plasma concentration ratio, which is greater than 0.8, and for most of these drugs it is near 1. For all drugs that are currently used for the treatment of CNS infections, the evaluation of pharmacokinetic/pharmacodynamic parameters, on the basis of dosing regimens and their time-dependent or concentration-dependent pattern of bacterial killing, remains an important aspect of clinical investigation and medical practice.

We report on the treatment with micafungin of a pacemaker-associated endocarditis due to Candida albicans. Antifungal therapy was able to reduce vegetation size from 5 to 1 cm making possible the transvenous removal of the device without a high risk of pulmonary embolism. Noteworthy, a high micafungin concentration was documented into the lead vegetation (10 μg/g of vegetation tissue) and this may have contributed to the striking size reduction of vegetation.

Purpose: The primary aim of the present study was to assess the pharmacokinetic bioequivalence between a generic formulation of meloxicam 15 mg tablets (Meloxicam Hexal) and its respective brand product (Mobic), in order to verify whether the generic product conforms to the regulatory standards of bioequivalence in the postmarketing setting. As a secondary exploratory aim, the pharmacodynamic effects of the two formulations were also evaluated by means of rating scales following hyperalgesia induced by cutaneous freeze injury., Subjects and Methods: A single 15 mg dose of generic or branded meloxicam tablets was administered to 24 healthy male volunteers in a crossover fashion. Plasma samples, collected for 24 hours after dosing, were assayed for meloxicam concentration by a validated highperformance liquid chromatography method., Results: THE ANALYSIS OF PHARMACOKINETIC PARAMETERS DID NOT SHOW ANY SIGNIFICANT DIFFERENCE BETWEEN THE TWO MELOXICAM FORMULATIONS: the 90% confidence intervals fell within the acceptance range of 80%-125% (0.84-1.16 for area under the curve [0-24], and 0.89-1.23 for peak concentration). No difference in the pharmacodynamic end point was observed between the two groups., Conclusion: The pharmacokinetic profiles of the two meloxicam formulations confirm the regulatory criteria for bioequivalence; pharmacodynamic data indicate a similar antihyperalgesic effect. The two formulations can be used interchangeably in the clinical setting.

Aims: To evaluate UFT and cyclophosphamide (CTX) based metronomic chemotherapy plus celecoxib (CXB) for the treatment of patients with heavily pre-treated advanced gastrointestinal malignancies., Methods: Thirty-eight patients received 500 mg/mq(2) CTX i.v bolus on day 1 and, from day 2, 50 mg/day CTX p.o. plus 100 mg/twice a day UFT p.o. and 200 mg/twice a day CXB p.o. Tegafur, 5-FU, 5-FUH(2), GHB and uracil pharmacokinetics were assessed. Plasma vascular endothelial growth factor (VEGF), soluble VE-cadherin (sVE-C) and thrombospondin-1 (TSP-1) levels were detected by ELISA and real-time PCR of CD133 gene expression on peripheral blood mononuclear cell was also performed., Results: Seventeen patients (45%) obtained stable disease (SD) with a median duration of 5.8 ms (range, 4.2-7.4). Median progression free survival (PFS) and overall survival (OS) were 2.7 ms (95% CI, 1.6-3.9 ms) and 7.1 ms (95% CI, 4.3-9.9 ms), respectively. No toxicities of grade >1 were observed. Pharmacokinetics of 27 patients (13/14, SD/progressive disease, PD) after the first treatment of UFT revealed that 5-FU AUC and C(max) values greater than 1.313 h × μg/ml and 0.501 μg/ml, respectively, were statistically correlated with stabilization of disease and prolonged PFS/OS. VEGF and sVE-C plasma levels were greater in the PD group when compared to SD group. CD133 expression increased only in the PD patients., Conclusion: Metronomic UFT and CTX with CXB in heavily pre-treated gastrointestinal patients were well tolerated and associated with interesting activity. Potential predictive pharmacokinetic parameters and pharmacodynamic biomarkers have been found.

The authors evaluated the influence of 5-fluorouracil (5-FU) on treatment tolerability in 81 colorectal cancer patients given adjuvant 5-FU intravenously plus folinic acid for 6 cycles. The pharmacokinetics of 5-FU and its inactive metabolite 5-fluoro-5,6-dihydrouracil (5-FDHU) were measured on days 1 and 5 of the first chemotherapy cycle, 5 and 45 minutes after bolus administration. 5-FU clearance was significantly lower on day 5 (62.64 ± 20.16 L/h/m(2)) than on day 1 (74.83 ± 31.61 L/h/m(2)). The lower 5-FU clearance values also predicted the side effects during the entire course of chemotherapy. In particular, patients with low clearance values on day 1 had a further reduction in this parameter on day 5, associated with severe toxicities. In conclusion, 5-FU alters its clearance, which could be partly due to a reduction in 5-FDHU biotransformation. These findings have safety implications for poor metabolizers whose drug clearance may fall below the threshold during repeated treatment cycles.

Purpose: Aim of this phase I study was to identify the maximum tolerated dose and dose limiting toxicity of continuous infusion of Irinotecan through a port-a-cath placed in the hepatic artery in patients with hepatocellular carcinoma and cirrhosis to explore new strategies in advanced hepatocellular carcinoma. Response rate and time-to-progression were analysed., Methods: Irinotecan was delivered as a five-day continuous infusion every 21 days, with increases of 2.5mg/m(2)/day every three patients, starting from 7.5mg/m(2)/day. Dose limiting toxicity corresponded to one patient in each triplet developing G4 haematological or G3 non-haematological toxicity, confirmed in two triplets. Twenty-eight patients (17 Child-Pugh A, 11 B) received treatment and tumour response was assessed after three courses completed by 22 patients., Results: Dose limiting toxicity was G3 diarrhoea in two patients, reached at 27.5mg/m(2)/day and the recommended dose was set at 25mg/m(2)/day. Nineteen of 30 patients experienced adverse events related to porth-a-cath placement and one died from liver ischemia and sepsis. Median time-to-progression was 11.3 months., Conclusion: Intrarterial infusion of Irinotecan is feasible in patients with hepatocellular carcinoma on cirrhosis at a recommended dose of 25mg/m(2)/day, with no major adverse drug-related events, but with some concerns about the insertion and management of the intra-arterial device., (Copyright © 2011 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

Fluoropyrimidines, including 5-fluorouracil (5-FU), are widely used in the treatment of solid tumors and remain the backbone of many combination regimens. Despite their clinical benefit, fluoropyrimidines are associated with gastrointestinal and hematologic toxicities, which often lead to treatment discontinuation. 5-FU undergoes complex metabolism, dihydropyrimidine dehydrogenase (DPD) being the rate-limiting enzyme of inactivation of 5-FU and its prodrugs. Several studies have demonstrated significant associations between severe toxicities by fluoropyrimidines and germline polymorphisms of DPD gene. To date, more than 30 SNPs and deletions have been identified within DPD, the majority of these variants having no functional consequences on enzymatic activity. However, the identification of deficient DPD genotypes may help identify poor-metabolizer patients at risk of developing potentially life-threatening toxicities after standard doses of fluoropyrimidines.

Aims: ABCB1 is a transmembrane transporter that is expressed in excretory organs (kidneys and liver), in intestine mucosa and on the blood-brain barrier. Because of the particular distribution of the protein, the activity of ABCB1 may significantly affect drug pharmacokinetics during absorption and distribution. Of note, several SNPs of ABCB1 are known and many of them affect transporter activity and/or expression. In this view, changes in the pharmacokinetics of drugs that are ABCB1 substrates could be clinically relevant and the evaluation of ABCB1 SNPs should deserve particular attention. Therefore, the aim of the present study was to investigate the possible association between ABCB1 polymorphisms and clozapine plasma levels in psychotic patients., Materials & Methods: c.1236C>T (exon 12), c.2677G>T (exon 21) and c.3435C>T (exon 26) SNPs of ABCB1 were evaluated by PCR techniques, while plasma levels of clozapine and norclozapine were measured by HPLC in 40 men (aged, 47.6 +/- 16.6 years, median: 42 years) and 20 women (aged 40.7 +/- 11.4 years, median: 38 years) 1 month after the start of clozapine administration., Results: A total of three SNPs were in Hardy-Weinberg equilibrium, with a calculated frequency of the wild-type alleles of 0.54, 0.55 and 0.45 for SNPs on exons 12, 21 and 26, respectively. Patients with c.3435CC or c.2677GG genotypes had significantly lower dose-normalized clozapine levels than those who were heterozygous or TT carriers. More interestingly, c.3435CC patients (15 subjects) needed significantly higher daily doses of clozapine (246 +/- 142 mg/day) compared with the remaining 24 CT and 21 TT patients (140 +/- 90 mg/day) in order to achieve the same clinical benefit., Conclusion: c.3435CC patients require higher clozapine doses to achieve the same plasma concentrations as CT or TT patients, and ABCB1 genotyping should be considered as a novel strategy that should improve drug use.

Distribution of antineoplastic agents within tumors remains one of the major challenges in cancer chemotherapy because distribution is hampered by several factors related to the drug (its physicochemical characteristics) and to the neoplastic tissue (blood and lymphatic vasculature, cell density, extracellular matrix composition, and interstitium). The inhomogeneous distribution and structure of tumor vasculature lead to large avascular and hypoxic areas with low pH and high interstitial oncotic pressure. In these critical conditions, the gradient of drug concentrations from the vessels to the inner parts of the tumor is not sufficient to promote diffusion of pharmacologic agents. Again, cellular sequestration and binding to extracellular matrix represent further factors that limit drug distribution and reduce tumor sensitivity to chemotherapy. Several strategies have been investigated to circumvent drug resistance. The evaluation of liposomal and nanoparticle formulations and the characterization of newer bioreductive agents and drugs that should normalize tumor vasculature are in progress.

Purpose: Recent clinical studies have demonstrated a reduction of irinotecan (CPT-11) gastrointestinal toxicities when the CPT-11 is administered in combination with thalidomide in patients with diagnosis of colorectal cancer. The main purpose of this study was to investigate possible interactions between CPT-11 pharmacokinetics and thalidomide to explain the previously described gastrointestinal toxicity reduction., Methods: In our clinical trial, advanced cancer patients were treated with CPT-11 on a dose of 350 mg/m2 at day 1 every 3 weeks. Only at the first cycle, CPT-11 was administered in association with thalidomide on a dose of 400 mg/day given from day 1 to day 14. From the second cycle, the treatment was continued with irinotecan alone at the same dose. Pharmacokinetics analysis of irinotecan and its metabolites, SN-38 and SN-38-glucuronide, were performed at the first and second cycle., Results: A total of 19 patients entered the study. The pharmacokinetic analysis were performed on 16 patients. Pharmacokinetic data suggested a decreased metabolism of irinotecan into SN-38 and SN-38-glucuronide when it was administered with thalidomide. Indeed, area under the time-concentration curve (AUC) of SN-38 was significantly lower at the first cycle than the second cycle (0.99+/-0.45 hxmicrog/ml vs 1.34+/-0.65, respectively, P=0.027) whereas AUC of irinotecan and SN-38-glucuronide were higher at first cycle than second cycle (34.53+/-11.38 hxmicrog/ml vs. 28.42+/-12.23 hxmicrog/ml, P=0.064 and 2.39+/-1.21 h(microg/ml vs. 1.86+/-1.11 hxmicrog/ml, P=0.018, respectively)., Conclusions: Our study demonstrates a significant decreased metabolism of CPT-11 into the active metabolite SN-38 when CPT-11 is administered in association with thalidomide. These observations strongly suggest an interaction of thalidomide with CPT-11 metabolism and, at least in part, it might explain the previously described improvement in tolerability.

Background and Objectives: Dihydropyrimidine dehydrogenase (DPD) plays a key role in the catabolism of 5-fluorouracil (5-FU) to 5-fluoro-5,6-dihydrouracil (5-FDHU), and as such, an impairment of DPD has been recognized as an important factor for altered 5-FU and 5-FDHU pharmacokinetics, predisposing patients to the development of severe 5-FU-associated toxicity. Our objectives were to avoid severe 5-FU toxicities in patients with greatly impaired 5-FU and 5-FDHU pharmacokinetics after the administration of a reduced test dose of 5-FU and to investigate possible 5-FU or 5-FDHU pharmacokinetic parameters of the test dose related to the most common drug toxicities that affect patients after the first cycle of 5-FU chemotherapy., Methods: Pharmacokinetics of 5-FU/5-FDHU and DPD activity in peripheral blood mononuclear cells (PBMCs) were examined in 188 gastrointestinal cancer patients given a test dose of 5-FU, 250 mg/m2, 2 weeks before starting the planned 5-FU treatment of 370 mg/m2 plus l-folinic acid, 100 mg/m2, for 5 days every 4 weeks. Drug levels were examined by HPLC, and toxicities were graded according to World Health Organization criteria., Results: The 5-FU test dose was well tolerated in all patients. Of 188 patients, 3 (1.6%) had marked alterations of 5-FU/5-FDHU pharmacokinetics (ie, 5-FU half-life [t(1/2 beta)] >5 hours, 5-FU total body clearance [CL(TB)] <1 L x h(-1) x m(-2), and 5-FDHU time to reach maximum plasma concentration [t max] > or = 45 minutes); they were excluded from 5-FU treatments and treated with irinotecan, which was well tolerated. The plasma disposition of 5-FU in the remaining 185 patients revealed an area under the curve (AUC) of 3.73 +/- 2.18 h x microg/mL (mean +/- SD), maximum plasma concentration (Cmax) of 16.78 +/- 8.61 microg/mL, and t(1/2 beta) of 0.16 +/- 0.15 hour, whereas the CL(TB) was 65.67 +/- 31.86 L x h(-1) x m(-2). The 5-FDHU plasma profile showed a Cmax value of 3.64 +/- 1.94 microg/mL, whereas the t max value was 26.63 +/- 10.06 minutes, with an AUC value of 3.71 +/- 1.90 h x microg/mL. The PBMC DPD activity was 202.15 +/- 141.14 pmol 5-FDHU x min(-1) x mg(-1) protein (95% confidence interval, 165-239.3 pmol 5-FDHU x min(-1) x mg(-1) protein). A significant correlation between 5-FU AUC and 5-FDHU AUC was found (r = 0.5492, P < .0001), whereas a weaker correlation between PBMC DPD activity and both 5-FDHU AUC (r = 0.328, P = .0121) and 5-FDHU Cmax (r = 0.369, P = .0044) was found. Interestingly, no relationships between PBMC DPD activity and common toxicities were found, whereas 5-FDHU t max values greater than 30 minutes were associated with the risk of moderate to severe neutropenia and diarrhea (P = .0323 and P = .0138, respectively; chi-square test)., Conclusions: This study suggests a successful approach for preventing severe or life-threatening toxicities in gastrointestinal cancer patients who are candidates for standard 5-FU treatment by analyzing the 5-FU and 5-FDHU pharmacokinetic parameters after the administration of a reduced 5-FU test dose.

Administration of 5-fluorouracil (5-FU) may be associated with severe toxicities in patients who are deficient of dihydropyrimidine dehydrogenase (DPD) activity. For this reason, a sensitive HPLC method for the analysis of 5-FU and 5-fluoro-5,6-dihydrouracil (5-FDHU) was developed in the present study for the determination of DPD activity in nucleated cells of peripheral blood and pharmacokinetic analysis of 5-FU and 5-FDHU in humans. 5-FU and 5-FDHU were extracted from biologic matrices by adding sodium acetate, sodium sulfate, and diethyl ether/propanol. Dried samples were reconstituted in a mobile phase (KH2PO4 35 mmol/L, pH 4.0), isocratically eluted with a Hypersil C18 stationary phase (25 cm x 4.6 mm, 10 microm), and detected by a diode array detector (measurement and reference wavelengths, 215 and 360 nm, respectively). 5-Fluorocytosine (internal standard), 5-FDHU, and 5-FU were eluted within 13 minutes of the injection without interferences. Recoveries ranged between 81% to 85% for all compounds, and the method proved to be linear, with a coefficient of linearity of 0.999. The limits of detection and quantification were 3.2 and 16 ng/mL, respectively, and the within-day and between-day CV were less than 10% for both 5-FU and 5-FDHU. The present assay proved to be sufficiently sensitive and specific to evaluate cellular DPD activity and measure 5-FU and 5-FDHU plasma concentrations in cancer patients, thus allowing therapeutic 5-FU monitoring in patients and identification of DPD-deficient subjects at major risk of severe toxicities.

The study of the influence of genotype on drug activity and efficacy (pharmacogenetics) and the genome-wide approach to drug discovery and interpretation of complex pharmacological responses (pharmacogenomics) are gaining momentum in current molecular medicine. The reasons of the variable activity and tolerability of cancer chemotherapy are being unraveled by the discovery of genotypic alterations affecting pharmacokinetics and pharmacodynamics of drugs. Indeed, genetic variability may alter drug catabolism (i.e. dihydropyrimidine dehydrogenase for 5-fluorouracil, thiopurine-S-methyl transferase for thiopurines, aldehyde dehydrogenase for cyclophosphamide) and anabolism (i.e. thymidine phosphorylase for capecitabine, deoxycitidine kinase for gemcitabine). Moreover, increased expression of transporter systems (i.e. the ATP binding cassette (ABC) superfamily) is associated with reduction of the cytoplasmic levels of drugs which may be unable to exert a cytotoxic effect. Additional systems could protect tumor cells from drug cytotoxicity, including the DNA repair machinery (nucleotide excision repair (NER) and DNA alkyltransferases) and antiapoptotic systems (i.e. bcl-2). Finally, alterations of drug targets may be associated with a decrease in the effectiveness of chemotherapy (i.e. mutations affecting tubulin and topoisomerase I for taxanes and irinotecan, respectively, and increased expression of thymidilate synthase for 5-fluorouracil). Therefore, genetic analysis has the potential to predict treatment efficacy and tolerability. However, major problems encountered in pharmacogenetic and pharmacogenomic studies are the need of extensive validation of available technology, the difficulties in obtaining a suitable amount of tissue from patients during the course of their disease and the extremely complex regulation of gene function. From this perspective, the evaluation of the cellular effect of drugs in relation to protein expression and function (pharmacoproteomics) may be able to overcome these obstacles, and allow the optimisation of cancer chemotherapy in association with a pharmacogenetic approach.