Linezolid in the central nervous system: comparison between cerebrospinal fluid and plasma pharmacokinetics.

BACKGROUND: Linezolid is effective against methicillin-resistant Staphylococcus aureus, which may cause central nervous system (CNS) infections, but drug concentrations in plasma are characterized by a large inter-patient variability. Therefore, the present study was aimed at evaluating linezolid pharmacokinetics in plasma and cerebrospinal fluid (CSF) in 7 patients with external ventricular drainage, who received linezolid 600 mg twice daily as 1-h intravenous infusion to prevent CNS infections. METHODS: Plasma and CSF linezolid concentrations were measured by high-performance liquid chromatography (HPLC) after the 1(st) and 5(th) dose, and pharmacokinetics were evaluated by non-compartmental analysis. RESULTS: Values of the CSF area under the time/concentration curve (AUC) (range 18.2-85.5 and 19.6-160.5 h × mg/l at the 1st and 5th dose, respectively) were lower than those calculated in plasma (range 27.6-224.0 and 27.5-166.1 h × mg/l, respectively). For minimum inhibitory concentration (MIC) = 1 mg/l, CSF AUC/MIC values were nearly equal to or greater than 100 only in 2 subjects after the 1st and 5th dose, whereas mean time above the MIC (T > MIC) values were higher than 75% in only 3 patients. Similar results were obtained when pharmacokinetic/pharmacodynamic parameters were evaluated in plasma. CONCLUSION: The present results suggest that changes in linezolid doses and measurement of drug concentrations should be considered as useful strategies to optimize treatment in some patients.

A rapid high-performance liquid chromatography method to measure linezolid and daptomycin concentrations in human plasma.

Daptomycin and linezolid, recently introduced to treat severe Gram-positive infections, are effective against multidrug-resistant Gram-positive microorganisms such as methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis, and vancomycin-resistant Enterococci bacteria that are less sensitive or frankly resistant, including methicillin-resistant S. aureus. However, alteration of their plasma profile has been described in some patients and this may be associated with toxicities or selection of resistant strains. The measurement of plasma concentrations of both drugs may allow the identification of those subjects at major risk of adverse events. Therefore, a rapid and sensitive high-performance liquid chromatography method for the analysis of daptomycin and linezolid was developed and applied in clinical settings. Drugs were extracted from plasma by adding methanol and, after centrifugation, clear supernatants were injected into the high-performance liquid chromatography system. Isocratic elution (1.5 mL/min) was performed using a mobile phase consisting of ammonium phosphate buffer 40 mM, pH 4.0, acetonitrile (70:30, vol/vol) through a BDS C8 Hypersil stationary phase (250 x 4.6 mm, 5 mum); ultraviolet detection was used at 214 nm. Linezolid and daptomycin eluted within 20 minutes from the injection, and mean recoveries ranged between 95.4% and 112.1%, respectively. The method was linear (coefficient of linearity, 0.998-0.999) over the full range of concentrations assayed, from 0.78125 mg/L (limit of quantitation) to 100 mg/L for both drugs. The Sy.x values were equal to 0.25 +/- 0.10 and 0.29 +/- 0.18 mg/L for daptomycin and linezolid, respectively. Precision values were lower than 20% over the entire range of calibration standard, and accuracy was within the range of 80% to 120% for all concentrations. The present method proved to be sensitive and specific to measure daptomycin and linezolid plasma concentrations in patients affected by severe Gram-positive infections, allowing therapeutic drug monitoring in those patients at major risk of severe adverse events.

Healthy volunteers and early phases of clinical experimentation.

The main goal of early phase trials is to gain knowledge about the clinical suitability of novel compounds, without pursuing specific therapeutic purposes. Healthy volunteers usually represent the ideal model for conducting phase I clinical trials, in order to investigate pharmacokinetics and pharmacodynamics as well as to document safety and tolerability without interference by concomitant pathological conditions. The increasing cost of novel drug development, in conjunction with ethical considerations, has fostered a new procedure for first-in-man trials, designated as "phase 0," which is conducted very early on a limited number of healthy volunteers who are exposed to low drug levels. The present review discusses issues concerning the enrollment of healthy volunteers in the early phase of drug development from different points of view, with some focus on the Italian experience. From the ethical standpoint, much discussion revolves around payments to healthy volunteers. Most authors agree that an adequate remuneration must be provided to healthy subjects, while avoiding coercion and excessive psychological pressure. Pending the lack of international and national guidelines, our center for clinical drug experimentation has implemented an operative procedure to estimate payments for healthy volunteers based on specific items, including restriction, time spent, discomfort, and risk. Other unresolved issues about the recruitment of healthy volunteers are represented by the lack of international consensus on the definition of healthy status and the need for guidelines about advertisement on clinical trials addressed to potential participants.

Synergistic cytotoxicity and molecular interaction on drug targets of sorafenib and gemcitabine in human pancreas cancer cells.

BACKGROUND: Current treatments have a modest impact on survival of pancreatic cancer patients and this study investigates the interaction between sorafenib and gemcitabine and the molecular pharmacodynamics of this combination. METHODS: The pancreatic cancer cells were treated with sorafenib and gemcitabine, alone or in combination. The effects of treatments were evaluated on cell proliferation, cell cycle, apoptosis, phosphorylation of Akt, c-Kit, ERK and VEGFR2, and expression of genes related to drug activity. RESULTS: Gemcitabine and sorafenib synergistically interacted on the inhibition of cell proliferation, and assessment of apoptosis demonstrated that drug associations increased the apoptotic index. Sorafenib reduced c-Kit, ERK and VEGFR2 activation and on the other hand, gemcitabine inhibited Akt phosphorylation. Moreover, quantitative PCR showed that sorafenib modulated the expression of genes related to gemcitabine activity, while gemcitabine induced the expression of RKIP. CONCLUSION: These data demonstrate that gemcitabine and sorafenib combination displays a synergistic effect in pancreatic cancer cells.

Augmentation of clozapine with aripiprazole in severe psychotic bipolar and schizoaffective disorders: a pilot study.

AIM: To evaluate the efficacy and safety of the augmentation of clozapine with aripiprazole in patients with treatment-resistant schizoaffective and psychotic bipolar disorders in a retrospective manner. Pharmacodynamic and pharmacokinetic interactions between the two drugs were also investigated. PATIENTS: Three men and 4 women (median age 36 and 40 years, respectively) who had mean scores at BPRS and CGI-Severity of 59.1+/-12.0 and 5.4+/-0.5, respectively, were treated with clozapine (mean dose 292.9+/-220.7 mg/day). Patients received an adjunctive treatment with aripiprazole (mean dose 6.8 +/- 3.7 mg/day). Clozapine, norclozapine and aripiprazole plasma levels were measured by means of a high performance liquid chromatograpy with UV detection. RESULTS: Total scores at BPRS decreased significantly (from 59.1+/-12.0 to 51.1+/-15.6, p=0.007) after aripirazole augmentation. In particular, the factors "thought disorder" (from 10.4+/-4.4 to 9.0+/-4.5, p=.047) and "anergia" (from 10.0+/-2.7 to 8.0+/-2.4, p=.018) significantly improved. Concomitant administration of aripiprazole and clozapine did not result in an increase in side effects over the period of treatment. Dose-normalized plasma levels of both clozapine and norclozapine and the clozapine/norclozapine metabolic ratio in all patients did not vary as well. CONCLUSION: The augmentation of clozapine with aripirazole was safe and effective in severe psychotic schizoaffective and bipolar disorders which failed to respond to atypical antipsychotics. A possible pharmacokinetic interaction between clozapine and aripiprazole does not account for the improved clinical benefit obtained after aripiprazole augmentation.

Regulation of enteric functions by adenosine: pathophysiological and pharmacological implications.

The wide distribution of ATP and adenosine receptors as well as enzymes for purine metabolism in different gut regions suggests a complex role for these mediators in the regulation of gastrointestinal functions. Studies in rodents have shown a significant involvement of adenosine in the control of intestinal secretion, motility and sensation, via activation of A1, A2A, A2B or A3 purinergic receptors, as well as the participation of ATP in the regulation of enteric functions, through the recruitment of P2X and P2Y receptors. Increasing interest is being focused on the involvement of ATP and adenosine in the pathophysiology of intestinal disorders, with particular regard for inflammatory bowel diseases (IBDs), intestinal ischemia, post-operative ileus and related dysfunctions, such as gut dysmotility, diarrhoea and abdominal discomfort/pain. Current knowledge suggests that adenosine contributes to the modulation of enteric immune and inflammatory responses, leading to anti-inflammatory actions. There is evidence supporting a role of adenosine in the alterations of enteric motor and secretory activity associated with bowel inflammation. In particular, several studies have highlighted the importance of adenosine in diarrhoea, since this nucleoside participates actively in the cross-talk between immune and epithelial cells in the presence of diarrhoeogenic stimuli. In addition, adenosine exerts complex regulatory actions on pain transmission at peripheral and spinal sites. The present review illustrates current information on the role played by adenosine in the regulation of enteric functions, under normal or pathological conditions, and discusses pharmacological interventions on adenosine pathways as novel therapeutic options for the management of gut disorders and related abdominal symptoms.

The genetics of the serotonin transporter and irritable bowel syndrome.

Serotonin transporter (SERT) mediates the intracellular reuptake of released serotonin, thus regulating its biological functions. Abnormalities in serotonin reuptake can alter enteric serotonergic signalling, leading to sensory, motor and secretory gut dysfunctions, which contribute to the pathophysiology of irritable bowel syndrome (IBS). This relationship has fostered the use of selective serotonin reuptake inhibitors (SSRIs) in the treatment of IBS. Current data on the efficacy of SSRIs in IBS, association of the SERT gene promoter polymorphism 5-HTTLPR with IBS and the expression pattern of SERT in the intestinal mucosa of IBS patients are conflicting. Recent molecular studies have raised critical questions about multiple SERT mRNA transcripts in the human gut, the role of polymorphic SERT promoter in the regulation of enteric SERT expression and the ability of 5-HTTLPR to affect human SERT gene transcription. The present review highlights recent advances in SERT genetics, discusses their implications for potential therapeutic applications of SSRIs in IBS and presents original suggestions for future investigations.

Lack of pharmacokinetic bioequivalence between generic and branded amoxicillin formulations. A post-marketing clinical study on healthy volunteers.

AIMS: There are concerns about the quality of generic drugs in the postmarketing setting. The aim was to establish whether two generic formulations of amoxicillin, available on the Italian market, fulfil the criteria for clinical pharmacokinetic bioequivalence vs. the branded drug. METHODS: Two generic amoxicillin products (generic A and B) were selected among four fast-release tablet formulations available on the Italian market. Twenty-four healthy adult volunteers of either sex participated to a single-dose, randomized, three-treatment, crossover, single-blind bioequivalence study designed to compare generic A and B with branded amoxicillin. Plasma samples were collected at preset times for 24 h after dosing, and assayed for amoxicillin levels by high-performance liquid chromatography. RESULTS: Ninety percent confidence intervals of AUC ratios were 0.8238, 1.0502 (ratio 0.9302) and 0.8116, 1.1007 (ratio 0.9452) for generic A and B vs. branded amoxicillin, respectively. Ninety percent confidence intervals of C(max) ratios were 0.7921, 1.0134 (ratio 0.8960) and 0.8246, 1.1199 (ratio 0.9610) for generic A and B vs. branded amoxicillin, respectively. The mean pharmacokinetic profiles showed that the AUC value of branded amoxicillin was 8.5 and 5.4% greater than that estimated for generic A and B, respectively. Few adverse events were recorded; these were not serious and occurred without apparent relationship to any specific amoxicillin formulation. CONCLUSIONS: These results indicate that one of the two marketed amoxicillin generics analysed in the present study is not bioequivalent to the brand leader product for C(max) on the basis of single-dose pharmacokinetic assessment.

Single nucleotide polymorphisms and clinical outcome in patients with biliary tract carcinoma treated with epirubicin, cisplatin and capecitabine.

BACKGROUND: Biliary tract carcinoma (BTC) is a rare highly malignant neoplasia. Polymorphisms at the xeroderma pigmentosum group D (XPD), excision repair cross-complementing group-1 (ERCC1) and X-ray repair cross complementing group 1 (XRCC1) genes were evaluated and correlated with clinical outcome. PATIENTS AND METHODS: Thirty-three patients with BTC were treated with intravenous or intra-arterial cisplatin and epirubicin and oral capecitabine. The ERCC1-C118T, XPD-Asp312Asn, XPD-Lys751Gln and XRCC1-Arg399Gln polymorphisms were studied. RESULTS: A partial response (PR) occurred in 6 patients. The median progression-free (PFS) and overall survival (OS) were 4.8 and 18.9 months, respectively. No significant correlations were observed between response, PFS and OS in patients grouped according to all the studied polymorphisms. The analysis of survival starting from diagnosis resulted in a significant association of the XRCC1-Arg399Arg variant with a shorter survival. CONCLUSION: A role of the XRCC1-Arg399Gln polymorphism as a possible prognostic factor in patients affected by BTC is suggested.

5-fluorouracil pharmacokinetics predicts disease-free survival in patients administered adjuvant chemotherapy for colorectal cancer.

PURPOSE: To evaluate 5-fluorouracil (5-FU) and 5-fluoro-5,6-dihydrouracil (5-FDHU) pharmacokinetics and disease-free survival (DFS) in colorectal cancer patients given 5-FU-based adjuvant chemotherapy within a nonrandomized, retrospective, pharmacokinetic study. EXPERIMENTAL DESIGN: One hundred fifteen patients including 72 men (median age, 63 years; range, 36-79 years) and 43 women (median age, 60 years; range, 36-73 years) received 6 cycles of l-leucovorin 100 mg/m(2)/day and 5-FU 370 mg/m(2)/day i.v. boluses (5 days every 4 weeks). Individual plasma concentrations of 5-FU and 5-FDHU were determined on day 1 of the first cycle with a validated high performance liquid chromatography method, and the main pharmacokinetic variables were determined. Follow-up of all patients was extended up to 5 years after the end of adjuvant chemotherapy, and DFS was recorded. Univariate and multivariate analyses were conducted to evaluate any correlation among 5-FU pharmacokinetics, clinical and pathologic variables, and DFS. RESULTS: The area under the time/concentration curve (AUC) of 5-FU was significantly lower in 58 subjects who recurred (7.5 +/- 2.9 h x mg/L) with respect to other patients (9.3 +/- 4.1 h x mg/L). Furthermore, AUC values lower than 8.4 h x mg/L together with lymph node involvement and the interruption of treatment or reduction of doses were identified as risk factors at univariate analysis. The completion of 6 cycles of adjuvant treatment without dosage modifications was the only independent risk factor at multivariate analysis, despite a trend toward significance for 5-FU AUC values (cutoff value, 8.4 hxmg/L) was observed (P = 0.06). CONCLUSIONS: Pharmacokinetics of 5-FU should be regarded as an important factor for predicting disease recurrence in colorectal cancers.

Correlation of CDA, ERCC1, and XPD polymorphisms with response and survival in gemcitabine/cisplatin-treated advanced non-small cell lung cancer patients.

PURPOSE: Selecting patients according to key genetic characteristics may help to tailor chemotherapy and optimize the treatment in non-small cell lung cancer (NSCLC). Polymorphisms at the xeroderma pigmentosum group D (XPD), excision repair cross-complementing 1 (ERCC1), and cytidine deaminase (CDA) genes have been associated with alterations in enzymatic activity and may change sensitivity to the widely used cisplatin-gemcitabine regimen. EXPERIMENTAL DESIGN: Analyses of CDA, XPD, and ERCC1 polymorphisms were done on blood samples of 65 chemotherapy-naïve, advanced NSCLC patients treated with cisplatin-gemcitabine. Furthermore, CDA enzymatic activity was evaluated by high-performance liquid chromatography analysis. Association between XPD Asp(312)Asn and Lys(751)Gln, ERCC1 C118T, and CDA Lys(27)Gln polymorphisms and response, clinical benefit, toxicity, time to progression (TTP), and overall survival (OS) was estimated using Pearson's chi(2) tests, the Kaplan-Meier method, the log-rank test, and the Cox proportional hazards model. RESULTS: The CDA Lys(27)Lys polymorphism significantly correlated with better clinical benefit (P = 0.04) and grade > or =3 neutropenia and thrombocytopenia, as well as with longer TTP and OS (P = 0.006 and P = 0.002, respectively), whereas no significant associations were found among ERCC1 and XPD polymorphisms and both response and clinical outcome. Finally, the enzymatic activity assay showed a significant lower mean in subjects harboring the CDA Lys(27)Lys polymorphism. CONCLUSIONS: Our data suggested the role of CDA Lys(27)Lys polymorphism as a possible predictive marker of activity, toxicity, TTP, and OS in advanced NSCLC patients treated with cisplatin and gemcitabine. These results may be explained by the lower enzymatic activity associated with the Lys(27)Lys CDA and offer a potential new tool for treatment optimization.

Laser microdissection and primary cell cultures improve pharmacogenetic analysis in pancreatic adenocarcinoma.

A key focus of research on pancreatic ductal adenocarcinoma (PDAC) is identifying new techniques to tailor gemcitabine and 5-fluorouracil treatments. Availability of tumor tissue is critical for the accurate assessment of gene expression, and laser microdissection (LMD) and primary cell cultures may be useful tools to separate tumor cells from the stromal reaction. The aim of this study was (1) to address the genetic profile relevant to drug activity and (2) to evaluate differences between microdissected and non-microdissected tumors, normal tissues, and primary cell cultures. Quantitative PCR of seven key genes was performed on mRNA from 113 microdissected and 28 non-microdissected tumors, a pool of normal tissues and four established primary cell lines. Protein expression was evaluated by western blot and immunocytochemistry and cytotoxicity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. LMD allowed the analysis of 110 samples and revealed significant differences in mRNA levels between microdissected tumors and normal tissues, as well as between non-microdissected and microdissected tumors from the same patients. In contrast, primary cell lines showed similar expression profiles with respect to their respective microdissected tumors. In particular, expression levels of human equilibrative nucleoside transporter-1 and thymydilate synthase were significantly related to gemcitabine and 5-fluorouracil cytotoxicity. We conclude that LMD is a reliable technique for mRNA extraction, and allows detection of significant differences in the expression of specific target genes when compared to non-microdissected specimens and normal tissues. Moreover, expression levels in microdissected tumors are similar to those observed in primary tumor cell cultures, both at mRNA and protein level, and are related to drug chemosensitivity. The use of these ex vivo techniques for molecular analysis of tumors therefore appears to be of some value in implementing the clinical management of PDAC.

Pharmacological modulation of adenosine system: novel options for treatment of inflammatory bowel diseases.

Inflammatory bowel diseases (IBDs) are chronic disorders resulting from abnormal and persistent immune responses which lead to severe tissue injury and disturbances in digestive motor/secretory functions. At present, pharmacotherapy represents the cornerstone for the management of IBDs, and recent advances in understanding the immunopathogenesis of intestinal inflammation suggest the adenosine system as an attractive target for development of novel drugs against gut inflammatory disorders. Consistent evidence indicates that adenosine plays a relevant role in the regulation of immune system via interaction with specific cell-membrane G-protein-coupled receptors (A(1), A(2a), A(2b), and A(3)). Moreover, this nucleoside is implicated in the control of enteric neurotransmission and gut motor functions. In the presence of inflammation, the adenosine system acts as a sensible sensor apparatus, which, through dynamic modifications in the expression of ecto-enzymes and purinergic receptors, adapts its metabolism to tissue health status and contributes to the mechanisms deputed to the protection of tissues against inflammatory injuries. In keeping with these concepts, it is becoming increasingly appreciated that drugs targeted on adenosine receptors or enzymes responsible for adenosine catabolism can exert beneficial effects on experimental models of intestinal inflammation. This review aims to discuss the role of adenosine in the regulation of enteric immune responses and gut neuromuscular functions in the presence of inflammation, as well as to highlight the mechanisms through which the pharmacological modulation of adenosine pathways may have potential applications for the therapeutic management of IBDs.

Statin-associated psychiatric adverse events: a case/non-case evaluation of an Italian database of spontaneous adverse drug reaction reporting.

BACKGROUND: The inhibitors of HMG-CoA reductase ('statins') are widely prescribed hypolipidaemic drugs, which have been evaluated in several clinical trials involving hundreds of thousands of patients. From a safety perspective, both clinical trials and post-marketing surveillance have demonstrated that statins are generally well tolerated, with rare serious adverse drug reactions (ADRs) that affect mainly muscle, liver and kidney. However, recent interest has been focused on a potential risk of psychiatric ADRs associated with statins, including memory loss, depression, suicidality, aggression and antisocial behaviour. Special attention is currently being paid to the potential for statin-induced sleep disorders. OBJECTIVE: To investigate the hypothesis that statins may be associated with psychiatric adverse events using quantitative and qualitative signal analysis. METHODS: The Interregional Group of Pharmacovigilance database holds reports of suspected ADRs submitted since 1988 from eight Italian regions. In the present analysis, only reports ranked at least 'possible', according to WHO causality assessment criteria, were considered. Association between statins and psychiatric events was assessed by the case/non-case methodology, calculating the ADR reporting odds ratio (ROR) as a measure of disproportionality. Cases were defined as patients with at least one reported ADR combined with the system organ class (SOC) 'psychiatric disorders'. The non-cases comprised all patients who did not experience an ADR related to the SOC 'psychiatric disorders'. Index reports comprised all ADR reports involving at least one statin, while all ADR reports not involving statins as suspected drugs were used as controls. RESULTS: According to selection criteria, 35,314 reports were included in the analysis. A total of 71 psychiatric preferred terms combined with statins were identified in 60 reports. Among them, 14 reports (23.3%) noted a positive rechallenge. Both the unadjusted (0.8; 95% CI 0.6, 1.1) and adjusted ROR (0.7; 95% CI 0.6, 1.0) suggested a lower rate of reports of psychiatric events for statins as a whole class compared with all other drugs, although the difference was not significant. The five most frequently reported psychiatric events combined with statins were insomnia, somnolence, agitation, confusion and hallucination. Only insomnia was reported with higher frequency for statins compared with all other drugs (ROR = 3.3; 95% CI 1.9, 5.7), while confusion was reported with a lower frequency (ROR = 0.4; 95% CI 0.1, 0.9). Amongst statins available in Italy, only simvastatin (ROR = 0.5; 95% CI 0.2, 0.9) showed a significantly lower rate of reports of psychiatric events compared with all other drugs together. CONCLUSION: A relatively small number of possible statin-associated psychiatric ADRs have been found in our database. No significant risks for a higher overall reporting of psychiatric ADRs associated with statins were identified in comparison with all other drugs combined. However, statin-associated insomnia resulted in a significant ROR that requires further investigation.

Clinical efficacy of esomeprazole in the prevention and healing of gastrointestinal toxicity associated with NSAIDs in elderly patients.

NSAIDs are widely prescribed for the treatment of pain, inflammation and rheumatic disorders, but their use is associated with adverse gastrointestinal effects, ranging from dyspeptic symptoms and peptic ulcers to more serious complications. Elderly patients are at high risk of experiencing NSAID-induced gastrointestinal tract injury and should be considered candidates for prophylactic pharmacological therapy. In studies conducted in adult patients, proton pump inhibitors (PPIs) such as esomeprazole have been shown to prevent or reduce NSAID-induced gastrointestinal injury. The beneficial effects of esomeprazole can be ascribed largely to its ability to maintain sustained inhibition of gastric acid secretion, although there is evidence to suggest that pharmacodynamic properties unrelated to acid inhibition may also contribute to the gastroprotective effects of this agent. Although there are limited data on the use of esomeprazole specifically in elderly patient populations, studies of patients at high risk of NSAID-induced gastrointestinal toxicity because of advanced age indicate that this PPI is both effective and well tolerated when administered in conjunction with NSAIDs. Thus, esomeprazole can be regarded as a useful option for prophylactic therapy in elderly patients receiving long-term NSAID therapy.

Fatal hepatitis after long-term pulse itraconazole treatment for onychomycosis.

OBJECTIVE: To report the occurrence of acute cytolytic hepatitis in a patient exposed to pulse itraconazole therapy for 24 weeks and provide a concise review of the literature on cases of itraconazole-induced hepatitis. CASE SUMMARY: A 61-year-old woman with no apparent risk factors for liver injury developed acute hepatitis one week after the final dose of a long-term course of pulse itraconazole therapy (200 mg orally twice daily, 1 wk on, 3 wk off, for 24 wk) for onychomycosis. Monitoring of liver enzymes was not performed during the treatment period. Serologic evaluations on presentation ruled out infectious diseases or other etiological factors. Liver function tests showed alanine aminotransferase 3330 U/L, aspartate aminotransferase 3250 U/L, and bilirubin 21 mg/dL. Liver function continued to deteriorate, and the patient underwent liver transplantation 17 days after admission. Her liver displayed reduced volume and there was a mild accumulation of ascitic fluid in the retroperitoneal cavity. Histologic evaluation showed massive panlobular necrosis. Complications occurred after transplantation and a rejection crisis worsened the clinical picture until the patient died about 4 months later. Use of the Naranjo probability scale showed the relationship of itraconazole therapy and the occurrence of acute hepatitis as probable. DISCUSSION: Itraconazole pulse therapy for onychomycosis appears to be at least as effective as and safer than a continuous treatment regimen, particularly from the perspective of potential liver damage. Only one case of severe symptomatic hepatitis occurring after pulse therapy with itraconazole for onychomycosis and requiring transplantation has been reported previously. In that case, as well as the one reported here, hepatitis symptoms occurred after completion of long-term treatment in patients who were asymptomatic both before and during therapy. CONCLUSIONS: Prolonged exposure to itraconazole, administered either continuously or intermittently, may precipitate severe and irreversible hepatotoxic events. Accordingly, careful monitoring of liver function parameters should be performed both during and after treatment when onychomycosis requires prolonged itraconazole administration, even in asymptomatic patients lacking apparent risk factors of hepatic injury.

Severe thrombocytopenia and haemolytic anaemia associated with ciprofloxacin: a case report with fatal outcome.

Haematological adverse reactions associated with fatal outcome are rare during treatment with ciprofloxacin. A 30-year old Caucasian man reported with abdominal pain and jaundice after 3-day administration of oral ciprofloxacin for a suspect of urinary tract infection. Clinical evaluations suggested an initial diagnosis of severe thrombocytopenia and haemolysis. The patient progressively developed petechiae and purpura on thorax and lower limbs. Despite pharmacological and supportive interventions, laboratory parameters worsened and the patient died 17 hours after admission. An accurate autopsy revealed most organs with diffuse petechial haemorrhages. No signs of bone marrow depression were found. No thrombi or signs of microangiopathies were observed in arterial vessels. Blood and urine cultures did not show any bacterial growth. This case report shows that ciprofloxacin may precipitate life-threatening thrombocytopenia and haemolytic anaemia, even in the early phases of treatment and without apparent previous exposures.

Transcription analysis of human equilibrative nucleoside transporter-1 predicts survival in pancreas cancer patients treated with gemcitabine.

Gene expression analysis may help the management of cancer patients, allowing the selection of subjects responding to treatment. The aim of this study was the characterization of expression pattern of genes involved in gemcitabine activity in pancreas tumor specimens and its correlation with treatment outcome. The role of drug transport and metabolism on gemcitabine cytotoxicity was examined with specific inhibitors, whereas transcription analysis of human equilibrative nucleoside transporter-1 (hENT1), deoxycytidine kinase (dCK), 5'-nucleotidase (5'-NT), cytidine deaminase (CDA), and ribonucleotide reductase subunits M1 and M2 (RRM1 and RRM2) was done by quantitative reverse transcription-PCR in tumor tissue isolated by laser microdissection from surgical or biopsy samples of 102 patients. Association between clinical outcome and gene expression levels was estimated using Kaplan-Meier method and Cox's proportional hazards model. Transport and metabolism had a key role on gemcitabine sensitivity in vitro; moreover, hENT1, dCK, 5'-NT, CDA, RRM1, and RRM2 were detectable in most tumor specimens. hENT1 expression was significantly correlated with clinical outcome. Patients with high levels of hENT1 had a significantly longer overall survival [median, 25.7; 95% confidence interval (95% CI), 17.6-33.7 months in the higher expression tertile versus median, 8.5; 95% CI, 7.0-9.9 months in the lower expression tertile]. Similar results were obtained with disease-free survival and time to disease progression, and the multivariate analysis confirmed the prognostic significance of hENT1. This study suggests that the expression levels of hENT1 may allow the stratification of patients based on their likelihood of survival, thus offering a potential new tool for treatment optimization.

Biosimilar drugs : concerns and opportunities.

Patents for biologic agents first marketed in the 1980s are now beginning to expire, opening the door for 'non-proprietary' versions of these agents to enter the market. However, there are fundamental differences between biologics and traditional pharmaceuticals that preclude the extrapolation of existing regulatory processes for traditional generic agents to these new biologic products. These include differences in dimensions (molecular weight), synthesis, purification, stability, and immunogenicity. There is also controversy over the terminology of these biologic agents, with a number of terms put forward. European regulatory authorities have adopted the term 'biosimilars,' while the US FDA prefers the term 'follow-on biologics.' It is important that these terms are not used as synonyms for 'generics,' and already there are moves to prevent classification of these products as 'generics.' In this review, we focus on the differences that exist between generics and biosimilars, and assess the current scenario of problems and opportunities. Furthermore, we also attempt to highlight the problems with establishing regulatory guidelines and those associated with the introduction of these drugs into clinical practice.

CCK2 receptors mediate inhibitory effects of cholecystokinin on the motor activity of guinea-pig distal colon.

Cholecystokinin and related peptides are involved in the control of intestinal motility and cholecystokinin receptor ligands might represent new pharmacological tools for the treatment of symptoms associated with functional bowel disorders. However, the respective roles played by cholecystokinin receptor subtypes and the mechanisms underlying these regulatory actions remain undetermined. This study was designed to examine the influence of cholecystokinin receptor subtypes on the motor activity of guinea-pig distal colon. The effects of drugs acting on CCK1 and CCK2 receptors were assessed in vitro on the contractile activity of longitudinal smooth muscle, both under basal conditions and in the presence of transmural electrical stimulation or KCl-induced contractions. The application of cholecystokinin octapeptide sulphate (cholecystokinin-8S) to colonic preparations induced concentration-dependent contractions which were prevented by devazepide (CCK1 receptor antagonist), enhanced by GV150013 (CCK2 receptor antagonist) or N(omega)-nitro-L-arginine methylester (L-NAME, nitric oxide synthase inhibitor), and unaffected by tetrodotoxin. The application of gastrin-17 to colonic preparations resulted in relaxant responses which were insensitive to devazepide, and prevented by GV150013, L-NAME or tetrodotoxin. L-NAME, N(omega)-propyl-L-arginine (NPA, neuronal nitric oxide synthase inhibitor) or GV150013 enhanced electrically evoked contractile responses, whereas devazepide did not. When tested in the presence of L-NAME or NPA the enhancing effect of GV150013 on electrically induced contractions no longer occurred. In the presence of KCl-induced pre-contractions, cholecystokinin-8S or gastrin-17 evoked concentration-dependent relaxations, which were unaffected by devazepide and were counteracted by GV150013, L-NAME, NPA or tetrodotoxin. In conclusion, the present results indicate that, at level of distal colon, CCK1 receptors mediate direct contractile effects on smooth muscle, whereas CCK2 receptors on enteric neurons mediate relaxant responses via nitric oxide release.