Once-daily oral omadacycline versus twice-daily oral linezolid for acute bacterial skin and skin structure infections (OASIS-2): a phase 3, double-blind, multicentre, randomised, controlled, non-inferiority trial.

BACKGROUND: Pathogen resistance and safety concerns limit oral antibiotic options for the treatment of acute bacterial skin and skin structure infections (ABSSSI). We aimed to compare the efficacy and safety of once-daily oral omadacycline, an aminomethylcycline antibiotic, versus twice-daily oral linezolid for treatment of ABSSSI. METHODS: In this phase 3, double-blind, randomised, non-inferiority study, eligible adults with ABSSSI at 33 sites in the USA were randomly assigned (1:1) to receive omadacycline (450 mg orally every 24 h over the first 48 h then 300 mg orally every 24 h) or linezolid (600 mg orally every 12 h) for 7-14 days. Randomisation was done via an interactive response system using a computer-generated schedule, and stratified by type of infection (wound infection, cellulitis or erysipelas, or major abscess) and receipt (yes or no) of allowed previous antibacterial treatment. Investigators, funders, and patients were masked to treatment assignments. Primary endpoints were early clinical response, 48-72 h after first dose, in the modified intention-to-treat (mITT) population (randomised patients without solely Gram-negative ABSSSI pathogens at baseline), and investigator-assessed clinical response at post-treatment evaluation, 7-14 days after the last dose, in the mITT population and clinically evaluable population (ie, mITT patients who had a qualifying infection as per study-entry criteria, received study drug, did not receive a confounding antibiotic, and had an assessment of outcome during the protocol-defined window). The safety population included randomised patients who received any amount of study drug. We set a non-inferiority margin of 10%. This study is registered with ClinicalTrials.gov, NCT02877927, and is complete. FINDINGS: Between Aug 11, 2016, and June 6, 2017, 861 participants were assessed for eligibility. 735 participants were randomly assigned, of whom 368 received omadacycline and 367 received linezolid. Omadacycline (315 [88%] of 360) was non-inferior to linezolid (297 [83%] of 360) for early clinical response (percentage-point difference 5·0, 95% CI -0·2 to 10·3) in the mITT population. For investigator-assessed clinical response at post-treatment evaluation, omadacycline was non-inferior to linezolid in the mITT (303 [84%] of 360 vs 291 [81%] of 360; percentage-point difference 3·3, 95% CI -2·2 to 9·0) and clinically evaluable (278 [98%] of 284 vs 279 [96%] of 292; 2·3, -0·5 to 5·8) populations. Mild to moderate nausea and vomiting were the most frequent treatment-emergent adverse events in omadacycline (111 [30%] of 368 and 62 [17%] of 368, respectively) and linezolid (28 [8%] of 367 and 11 [3%] of 367, respectively) groups. INTERPRETATION: Once-daily oral omadacycline was non-inferior to twice-daily oral linezolid in adults with ABSSSI, and was safe and well tolerated. Oral-only omadacycline represents a new treatment option for ABSSSI, with potential for reduction in hospital admissions and cost savings. FUNDING: Paratek Pharmaceuticals.

Omadacycline for Acute Bacterial Skin and Skin-Structure Infections.

BACKGROUND: Acute bacterial skin and skin-structure infections are associated with substantial morbidity and health care costs. Omadacycline, an aminomethylcycline antibiotic that can be administered once daily either orally or intravenously, is active against pathogens that commonly cause such infections, including antibiotic-resistant strains. METHODS: In this double-blind trial, we randomly assigned adults with acute bacterial skin and skin-structure infections (in a 1:1 ratio) to receive omadacycline (100 mg given intravenously every 12 hours for two doses, then 100 mg given intravenously every 24 hours) or linezolid (600 mg given intravenously every 12 hours). A transition to oral omadacycline (300 mg every 24 hours) or oral linezolid (600 mg every 12 hours) was allowed after 3 days; the total treatment duration was 7 to 14 days. The primary end point was an early clinical response at 48 to 72 hours, defined as survival with a reduction in lesion size of at least 20% without rescue antibacterial therapy. A secondary end point was an investigator-assessed clinical response at the post-treatment evaluation 7 to 14 days after the last dose, with clinical response defined as survival with resolution or improvement in signs or symptoms of infection to the extent that further antibacterial therapy was unnecessary. For both end points, the noninferiority margin was 10 percentage points. RESULTS: In the modified intention-to-treat population, omadacycline (316 patients) was noninferior to linezolid (311 patients) with respect to early clinical response (rate of response, 84.8% and 85.5%, respectively; difference, -0.7 percentage points; 95% confidence interval [CI], -6.3 to 4.9). Omadacycline also was noninferior to linezolid with respect to investigator-assessed clinical response at the post-treatment evaluation in the modified intention-to-treat population (rate of response, 86.1% and 83.6%, respectively; difference, 2.5 percentage points; 95% CI, -3.2 to 8.2) and in the clinical per-protocol population (96.3% and 93.5%, respectively; difference, 2.8 percentage points; 95% CI, -1.0 to 6.9). In both groups, the efficacy of the trial drug was similar for methicillin-susceptible and methicillin-resistant Staphylococcus aureus infections. Adverse events were reported in 48.3% of the patients in the omadacycline group and in 45.7% of those in the linezolid group; the most frequent adverse events in both groups were gastrointestinal (in 18.0% and 15.8% of the patients in the respective groups). CONCLUSIONS: Omadacycline was noninferior to linezolid for the treatment of acute bacterial skin and skin-structure infections and had a similar safety profile. (Funded by Paratek Pharmaceuticals; OASIS-1 ClinicalTrials.gov number, NCT02378480 .).

Omadacycline for Community-Acquired Bacterial Pneumonia.

BACKGROUND: Omadacycline, a new once-daily aminomethylcycline antibiotic agent that can be administered intravenously or orally, reaches high concentrations in pulmonary tissues and is active against common pathogens that cause community-acquired bacterial pneumonia. METHODS: In a double-blind trial, we randomly assigned (in a 1:1 ratio) adults with community-acquired bacterial pneumonia (Pneumonia Severity Index risk class II, III, or IV) to receive omadacycline (100 mg intravenously every 12 hours for two doses, then 100 mg intravenously every 24 hours), or moxifloxacin (400 mg intravenously every 24 hours). A transition to oral omadacycline (300 mg every 24 hours) or moxifloxacin (400 mg every 24 hours), respectively, was allowed after 3 days; the total treatment duration was 7 to 14 days. The primary end point was early clinical response, defined as survival with improvement in at least two of four symptoms (cough, sputum production, pleuritic chest pain, and dyspnea) and no worsening of symptoms at 72 to 120 hours, without receipt of rescue antibacterial therapy. A secondary end point was investigator-assessed clinical response at a post-treatment evaluation 5 to 10 days after the last dose, with clinical response defined as resolution or improvement in signs or symptoms to the extent that further antibacterial therapy was unnecessary. A noninferiority margin of 10 percentage points was used. RESULTS: The intention-to-treat population included 386 patients in the omadacycline group and 388 patients in the moxifloxacin group. Omadacycline was noninferior to moxifloxacin for early clinical response (81.1% and 82.7%, respectively; difference, -1.6 percentage points; 95% confidence interval [CI], -7.1 to 3.8), and the rates of investigator-assessed clinical response at the post-treatment evaluation were 87.6% and 85.1%, respectively (difference, 2.5 percentage points; 95% CI, -2.4 to 7.4). Adverse events that emerged after treatment initiation were reported in 41.1% of the patients in the omadacycline group and 48.5% of the patients in the moxifloxacin group; the most frequent events were gastrointestinal (10.2% and 18.0%, respectively), and the largest difference was for diarrhea (1.0% and 8.0%). Twelve deaths (8 in the omadacycline group and 4 in the moxifloxacin group) occurred during the trial. CONCLUSIONS: Omadacycline was noninferior to moxifloxacin for the treatment of community-acquired bacterial pneumonia in adults. (Funded by Paratek Pharmaceuticals; OPTIC ClinicalTrials.gov number, NCT02531438 .).

Effect of Food on the Bioavailability of Omadacycline in Healthy Participants.

Omadacycline is a first-in-class aminomethylcycline antibiotic being evaluated in phase 3 studies as oral and intravenous monotherapy for bacterial infections. This was a phase 1, randomized, open-label, 4-period, crossover study that evaluated the effect of food consumption on the bioavailability of omadacycline. Healthy participant were randomized to 1 of 4 sequences, which included the following predose conditions in different orders (A) ≥6-hour fast, (B) high-fat, nondairy meal 4 hours before dosing, (C) high-fat, nondairy meal 2 hours before dosing, and (D) high-fat meal containing dairy 2 hours before dosing. Participants received a single 300-mg oral dose of omadacycline during each treatment period; periods were separated by ≥5 days. Blood samples for pharmacokinetic (PK) analysis were collected over 24 hours after each dose, and safety assessments were performed during each treatment period. Least-squares mean and 90% confidence intervals were compared for fed state vs fasted state. Thirty-one participants were included in the PK analysis. Fasted AUC0-∞ , AUC0-t , and AUC0-24 were 10.2, 7.2, and 7.2 µg·h/mL, respectively, and Cmax was 0.6 µg/mL. Compared with a fasted dose, bioavailability was reduced by 15% to 17% by a nondairy meal 4 hours before dosing, 40% to 42% by a nondairy meal 2 hours before dosing, and 59% to 63% for a dairy meal 2 hours before dosing. Two participants experienced adverse events (mild nausea, mild somnolence). A 300-mg oral dose of omadacycline administered within 2 to 4 hours after food had reduced bioavailability compared with the fasted state. Oral omadacycline should be administered in a fasted state.

Omadacycline: development of a novel aminomethylcycline antibiotic for treating drug-resistant bacterial infections.

Omadacycline is a first-in-class aminomethylcycline antibiotic that circumvents common tetracycline resistance mechanisms. In vitro omadacycline has potent activity against Gram-positive aerobic bacteria including methicillin-resistant Staphylococcus aureus, penicillin-resistant and multidrug-resistant Streptococcus pneumoniae, and vancomycin-resistant Enterococcus spp. It is also active against common Gram-negative aerobes, some anaerobes and atypical bacteria including Legionella spp. and Chlamydia spp. Ongoing Phase III clinical trials with omadacycline are investigating once daily doses of 100 mg intravenously followed by once-daily doses of 300 mg orally for the treatment of acute bacterial skin and skin structure infections and community-acquired bacterial pneumonia. This paper provides an overview of the microbiology, nonclinical evaluations, clinical pharmacology and initial clinical experience with omadacycline.

Tigeciclina versus vancomycin más aztreonam en el tratamiento de infecciones complicadas de piel y tejidos blandos: Experiencia en Latinoamérica / Tigecycline as effective as vancomycin plus aztreonam in the treatment of complicated skin and skin structure infections: Experience in Latin America

BACKGROUND: Treating complicated skin and skin structure infections (cSSSIs) can be challenging. Tigecycline was compared to vancomycin/aztreonam in patients with cSSSIs in a multinational trial; this article reports on the Latin American (LA) population. METHODS: Patients were randomly assigned to receive tigecycline or vancomycin/ aztreonam. Primary endpoint was clinical cure rate at test-of-cure (TOC). Several secondary endpoints and safety were also assessed. RESULTS: A subtotal of 167 LA patients from the multinational trial (N = 573) received ≥ 1 dose of study drug. At TOC, cure rates were similar between tigecycline and vancomycin/aztreonam in the clinically evaluable population.) Noninferiority of tigecycline could not be demonstrated (insufficient sample sizes). Tigecycline-treated patients had higher incidences of nausea, vomiting, anorexia; vancomycin/aztreonam-treated patients had higher incidences of pruritus and rash. CONCLUSIONS: Efficacy results in the LA population were consistent with the multinational study suggesting that tigecycline is noninferior to vancomycin/aztreonam in treating patients with cSSSI.

INTRODUCCIÓN: El tratamiento de infecciones complicadas de piel y tejidos blandos (ICPTB) puede representar un desafío. Se comparó la eficacia de tigeciclina versus vancomicina/aztreonam en pacientes con ICPTB en un estudio multicéntrico; este artículo se refiere a la experiencia en Latinoamérica (LA). MÉTODO: Se asignaron, en forma randomizada, los pacientes a dos grupos de tratamiento: tigeciclina o vancomicina/aztreonam. La meta a evaluar (outcome) primaria fue la curación clínica, denominada test de curación (TC). Se establecieron, además, metas secundarias y la evaluación de seguridad del fármaco. RESULTADOS: Un subtotal de 167 pacientes procedentes de LA, de un estudio multinacional que incluyó 573 pacientes, recibieron ≥ 1 dosis del fármaco en estudio. Al TC, los porcentajes de curación fueron similares entre tigeciclina y vanco-micina/aztreonam en los pacientes clínicamente evaluables). La no inferioridad de tigeciclina no pudo ser demostrada (tamaño de muestra insuficiente). Los pacientes tratados con tigeciclina tuvieron mayor incidencia de náuseas, vómitos y anorexia; los pacientes que recibieron vancomicina/aztreonam tuvieron mayor incidencia de prurito y rash. CONCLUSIONES: Los resultados de eficacia en LA fueron consistentes con el estudio multinacional sugiriendo que tigeciclina no es inferior a vancomicina/aztreonam en el tratamiento de pacientes con ICPTB.

Tigecycline: a case study.

The emergence of pathogenic bacteria resistant to virtually all available antibacterial agents at present has caused consternation among medical professionals, but has only intermittently raised concern among the public. This has led to a transient resurgence of interest in studying the mechanisms of resistance and in discovering and developing new antibacterial agents, but successes in the development of novel antibacterial agents have been few and far between. Although it has been known since the discovery of the tetracyclines that they are inhibitors of protein synthesis, there has been considerable recent progress on elucidating the mechanisms of action of the tetracyclines and in the enhanced understanding of the mechanisms of tetracycline resistance. In this case study, the authors discuss the discovery and development of a new class of antibacterials, which were derived from the tetracyclines, namely the glycylcyclines. This has resulted in the introduction of a new agent, tigecycline, to clinical practice. The glycylcyclines restore the antibacterial activity to levels of the earlier tetracyclines when they were first introduced, by overcoming the two major tetracycline-resistance mechanisms of efflux and ribosome protection, which promises to have a high degree of clinical utility.

Safety and efficacy of tigecycline in treatment of skin and skin structure infections: results of a double-blind phase 3 comparison study with vancomycin-aztreonam.

In a randomized, double-blind, controlled trial, 546 patients with complicated skin and skin structure infections received tigecycline 100 mg/day (a 100-mg initial dose and then 50 mg intravenously twice daily) or the combination of vancomycin 2 g/day (1 g intravenously twice daily) and aztreonam 4 g/day (2 g intravenously twice daily) for up to 14 days. The primary end point was the clinical response in the clinical modified intent-to-treat (c-mITT) and clinically evaluable (CE) populations at the test-of-cure visit 12 to 92 days after the last dose. The microbiologic response at the test-of-cure visit was also assessed. Safety was assessed by physical examination, laboratory results, and adverse event reporting. Five hundred twenty patients were included in the c-mITT population (tigecycline group, n = 261; combination group, n = 259), and 436 were clinically evaluable (tigecycline group, n = 223; combination group, n = 213). The clinical responses in the tigecycline and the combination vancomycin and aztreonam groups were similar in the c-mITT population (84.3% versus 86.9%; difference, -2.6% [95% confidence interval, -9.0, 3.8]; P = 0.4755) and the CE population (89.7% versus 94.4%; difference, -4.7% [95% confidence interval, -10.2, 0.8]; P = 0.1015). Microbiologic eradication (documented or presumed) occurred in 84.8% of the patients receiving tigecycline and 93.2% of the patients receiving vancomycin and aztreonam (difference, -8.5 [95% confidence interval, -16.0, -1.0]; P = 0.0243). The numbers of patients reporting adverse events were similar in the two groups, with increased nausea and vomiting rates in the tigecycline group and an increased incidence of rash and increases in alanine aminotransferase and aspartate aminotransferase levels in the combination vancomycin and aztreonam group. Tigecycline was shown to be safe and effective for the treatment of complicated skin and skin structure infections.

A multicenter trial of the efficacy and safety of tigecycline versus imipenem/cilastatin in patients with complicated intra-abdominal infections [Study ID Numbers: 3074A1-301-WW; ClinicalTrials.gov Identifier: NCT00081744].

BACKGROUND: Complicated intra-abdominal infections (cIAI) remain challenging to treat because of their polymicrobial etiology including multi-drug resistant bacteria. The efficacy and safety of tigecycline, an expanded broad-spectrum glycylcycline antibiotic, was compared with imipenem/cilastatin (IMI/CIS) in patients with cIAI. METHODS: A prospective, double-blind, multinational trial was conducted in which patients with cIAI randomly received intravenous (IV) tigecycline (100 mg initial dose, then 50 mg every 12 hours [q12h]) or IV IMI/CIS (500/500 mg q6h or adjusted for renal dysfunction) for 5 to14 days. Clinical response at the test-of-cure (TOC) visit (14-35 days after therapy) for microbiologically evaluable (ME) and microbiological modified intent-to-treat (m-mITT) populations were the co-primary efficacy endpoint populations. RESULTS: A total of 825 patients received >or= 1 dose of study drug. The primary diagnoses for the ME group were complicated appendicitis (59%), and intestinal (8.8%) and gastric/duodenal perforations (4.6%). For the ME group, clinical cure rates at TOC were 80.6% (199/247) for tigecycline versus 82.4% (210/255) for IMI/CIS (95% CI -8.4, 5.1 for non-inferiority tigecycline versus IMI/CIS). Corresponding clinical cure rates within the m-mITT population were 73.5% (227/309) for tigecycline versus 78.2% (244/312) for IMI/CIS (95% CI -11.0, 2.5). Nausea (31.0% tigecycline, 24.8% IMI/CIS [P = 0.052]), vomiting (25.7% tigecycline, 19.4% IMI/CIS [P = 0.037]), and diarrhea (21.3% tigecycline, 18.9% IMI/CIS [P = 0.435]) were the most frequently reported adverse events. CONCLUSION: This study demonstrates that tigecycline is as efficacious as imipenem/cilastatin in the treatment of patients with cIAI.

The efficacy and safety of tigecycline for the treatment of complicated intra-abdominal infections: analysis of pooled clinical trial data.

This pooled analysis includes 2 phase 3, double-blind trials designed to evaluate the safety and efficacy of tigecycline, versus that of imipenem-cilastatin, in 1642 adults with complicated intra-abdominal infections. Patients were randomized to receive either tigecycline (initial dose of 100 mg, followed by 50 mg intravenously every 12 h) or imipenem-cilastatin (500/500 mg intravenously every 6 h) for 5-14 days. The primary end point was the clinical response at the test-of-cure visit (12-42 days after therapy) in the co-primary end point microbiologically evaluable and microbiological modified intent-to-treat populations. For the microbiologically evaluable group, clinical cure rates were 86.1% (441/512) for tigecycline, versus 86.2% (442/513) for imipenem-cilastatin (95% confidence interval for the difference, -4.5% to 4.4%; P < .0001 for noninferiority). Clinical cure rates in the microbiological modified intent-to-treat population were 80.2% (506/631) for tigecycline, versus 81.5% (514/631) for imipenem-cilastatin (95% confidence interval for the difference, -5.8% to 3.2%; P < .0001 for noninferiority). Nausea (24.4% tigecycline, 19.0% imipenem-cilastatin [P = .01]), vomiting (19.2% tigecycline, 14.3% imipenem-cilastatin [P = .008]), and diarrhea (13.8% tigecycline, 13.2% imipenem-cilastatin [P = .719]) were the most frequently reported adverse events. This pooled analysis demonstrates that tigecycline was efficacious and well tolerated in the treatment of patients with complicated intra-abdominal infections.

Efficacy and safety of tigecycline monotherapy compared with vancomycin plus aztreonam in patients with complicated skin and skin structure infections: Results from a phase 3, randomized, double-blind trial.

OBJECTIVES: To compare the effect of tigecycline monotherapy, a first-in-class, expanded broad spectrum glycylcycline, with the combination of vancomycin and aztreonam (V + A) in the treatment of complicated skin and skin structure infections (cSSSI). METHODS: A phase 3, double-blind study conducted in 8 countries enrolled adults with cSSSI who required intravenous (IV) antibiotic therapy for > or =5 days. Patients were randomly assigned (1:1) to receive either tigecycline or V + A for up to 14 days. Primary endpoint was the clinical cure rate at the test-of-cure visit. Secondary endpoints included microbiologic efficacy and in vitro susceptibility to tigecycline of bacteria that cause cSSSI. Safety was assessed by physical examination, laboratory analyses, and adverse event reporting. RESULTS: A total of 596 patients were screened for enrollment, 573 were analyzed for safety, 537 were included in the clinical modified intent-to-treat (c-mITT) population, 397 were clinically evaluable (CE), and 228 were microbiologically evaluable (ME). At test-of-cure, cure rates were similar between tigecycline and V + A groups in the CE population (82.9% versus 82.3%, respectively) and in the c-mITT population (75.5% versus 76.9%, respectively). Microbiologic eradication rates (subject level) at test-of-cure in the ME population were also similar between tigecycline and V + A. Frequency of adverse events was similar between groups, although patients receiving tigecycline had higher incidence of nausea, vomiting, dyspepsia, and anorexia, while increased ALT/SGPT, pruritus, and rash occurred significantly more often in V + A-treated patients. CONCLUSIONS: This study demonstrates that the efficacy of tigecycline monotherapy for the treatment of patients with cSSSI is statistically noninferior to the combination of V + A.

Tigecycline is efficacious in the treatment of complicated intra-abdominal infections.

BACKGROUND: Empiric treatment of complicated intra-abdominal infections (cIAI) represents a clinical challenge because of the diverse bacteriology and the emergence of bacterial resistance. The efficacy and safety of tigecycline (TGC), a first-in-class, expanded broad-spectrum glycylcycline antibiotic, were compared with imipenem/cilastatin (IMI/CIS) in patients with cIAI. METHODS: In this prospective, double-blind, phase 3, multinational trial, patients were randomly assigned to intravenous (i.v.) TGC (100 mg initial dose, then 50 mg every 12 h) or i.v. IMI/CIS (500/500 mg every 6 h) for 5-14 days. Clinical response was assessed at the test-of-cure (TOC) visit (14-35 days after therapy) for microbiologically evaluable (ME) and microbiologically modified intent-to-treat (m-mITT) populations (co-primary efficacy endpoint populations in which cure/failure response rates were determined). RESULTS: Of 817 mITT patients (i.e., received > or = 1 dose of study drug), 641 (78%) comprised the m-mITT cohort (322 TGC, 319 IMI/CIS) and 523 (64%) were ME (266 TGC, 256 IMI/CIS). Patients were predominantly white (88%) and male (59%) with a mean age of 49 years. The primary diagnoses for the mITT group were complicated appendicitis (41%), cholecystitis (22%), and intra-abdominal abscess (11%). For the ME population, clinical cure rates at TOC were 91.3% (242/265) for TGC versus 89.9% (232/258) for IMI/CIS (95% CI -4.0, 6.8; P<0.001). Corresponding clinical cure rates within the m-mITT population were 86.6% (279/322) for TGC versus 84.6% (270/319) for IMI/CIS (95% CI -3.7, 7.5; P<0.001 for noninferiority TGC versus IMI/CIS). The most commonly reported adverse events for TGC and IMI/CIS were nausea (17.6% TGC versus 13.3% IMI/CIS; P=0.100) and vomiting (12.6% TGC versus 9.2% IMI/CIS; P=0.144). CONCLUSIONS: TGC is efficacious in the treatment of patients with cIAIs and TGC met per the protocol-specified statistical criteria for noninferiority to the comparator, IMI/CIS.

Results of a multicenter, randomized, open-label efficacy and safety study of two doses of tigecycline for complicated skin and skin-structure infections in hospitalized patients.

BACKGROUND: Tigecycline is a broad-spectrum glycylcycline antibiotic being investigated for the treatment of serious infections in hospitalized patients. Tigecycline has been shown to be efficacious against serious infections in animals, and preliminary studies in healthy adults have shown that tigecycline has an acceptable tolerability profile. OBJECTIVE: This study compared the clinical and microbiological efficacy, pharmacokinetic properties, and tolerability of 2 doses of tigecycline in hospitalized patients with a complicated skin and skin-structure infection (cSSSI). METHODS: This Phase II, randomized, open-label study was conducted between September 1999 and March 2001 at 14 investigative centers across the United States. Patients were randomized to receive tigecycline 25 or 50 mg IV q12h for 7 to 14 days. The primary efficacy end point was the clinically observed cure rate among clinically evaluable (CE) patients at the test-of-cure visit. Secondary end points were the clinical cure rate at the end of treatment and bacteriologic response in microbiologically evaluable (ME) patients. Also, in vitro tests of susceptibility to tigecycline were performed for selected pathogens known to cause skin infections, including methicillin-resistant and methicillin-susceptible Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Enterococcus faecium. Tolerability assessments also were conducted. RESULTS: A total of 160 patients received > or =1 dose of tigecycline; 109 patients were CE, and 91 were ME. The majority of patients (74%) were men, and the mean (SD) age was 49.0 (14.8) years. At the test-of-cure visit, the clinical cure rate in the 25-mg group was 67% (95% CI, 53.3%-79.3%) and in the 50-mg group was 74% (95% CI, 60.3%-85.0%). In the 25-mg group, 56% of the patients had eradication (95% CI, 40.0%-70.4%) of the pathogens compared with 69% (95% CI, 54.2%-82.3%) in the 50-mg group. Values for the minimum concentration of tigecycline that is inhibitory for 90% of all isolates ranged from 0.06 to 0.50 microg/mL for the selected pathogens. Both tigecycline doses were generally well tolerated. Nausea and vomiting were the most common adverse events. CONCLUSIONS: In this study, tigecycline appeared efficacious and showed a favorable pharmacokinetic profile and an acceptable safety profile in the treatment of hospitalized patients with cSSSI. In patients who received 50-mg doses of tigecycline q12h, the clinical cure rates and microbial eradication rates were 74% and 70%, respectively, and were 67% and 56% in patients who received 25-mg doses.

Dyslipidemias and HMG-CoA reductase inhibitor prescription in heart transplant recipients.

BACKGROUND: The treatment of dyslipidemias in orthotopic heart transplant (OHT) recipients is not highlighted in the National Cholesterol Education Program Adult Treatment Panel guidelines. Emerging data suggest that hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) safely reduce the risk of transplant rejection and coronary artery vasculopathy in OHT patients. OBJECTIVE: To assess the proportion of patients from our institution reaching the low-density lipoprotein cholesterol (LDL-C) target of <100 mg/dL, evaluate the impact of statins in reaching this goal, and evaluate the prescribing practice for statins in US OHT centers. METHODS: The management of dyslipidemia of OHT recipients followed at our institution was retrospectively evaluated. In addition, the use of statins in adult OHT centers in the US that performed >or=15 OHTs per year was assessed through a survey. RESULTS: Of the 328 patients from our institution, 58.5% achieved an LDL-C <100 mg/dL. Patients prescribed statins were more likely to reach this goal (p < 0.01). A total of 85.0% of centers responding to the survey use statins as a part of their post-OHT protocol, primarily to reduce coronary artery vasculopathy (70.6%). CONCLUSIONS: Due to the potential for improved outcomes, a large proportion of patients are prescribed a statin. Our results support previous findings that statins are safe and effective in reducing LDL-C in the management of dyslipidemias in OHT recipients. Nonetheless, dyslipidemias are suboptimally managed in many post-OHT patients.

Does competition for transplantable hearts encourage 'gaming' of the waiting list?

Transplant centers may "game" the severity of listed patients to increase their patients' likelihood of receiving transplantable organs. Recent lawsuits allege gaming at some centers, and listing policies were modified in 1999 to clarify listing criteria. We tested for gaming and its relationship to heart transplant center competition. We found that increased competition resulted in more patients listed in the most severe illness category (p < .01), consistent with the gaming hypothesis. Gaming was mitigated after the 1999 policy change (p > .05), which suggests that the new rules were effective. Continued monitoring is warranted, given prior gaming and recent accusations.

The effect of recipient cytokine gene polymorphism on cardiac transplantation outcome.

We determined the association between clinical outcomes after heart transplantation and gene polymorphism in five cytokines (tumor necrosis factor-alpha, transforming growth factor (TGF)-beta, interleukin-10, interleukin-6, and interferon-gamma) reported to influence expression in vitro. Ninety-five patients were studied. Cytokine genotyping was performed by sequence specific priming polymerase chain reaction. Clinical outcomes studied in the first posttransplant year included: (1) documented viral, bacterial, or fungal infection; (2) cytomegalovirus infection; (3) acute cellular rejection (International Society for Heart and Lung Transplantation > or = grade IIIA); (4) time to first rejection episode; and (5) the development of allograft vasculopathy. Patients with the TGF-beta genotype 10 T/T 25 G/G or 10 T/C 25 G/G had a longer time to first rejection (median time to first rejection episode 321 days) than those with the TGF-beta genotype 10C/C 25 G/C or 10 C/C 25 C/C (median time to first rejection 88 days). There was a trend toward a higher frequency of the tumor necrosis factor-alpha genotype -308 G/A or A/A in patients without infection (19/59, 32%) as compared with patients with infection (5/31, 16%). In both cases, these differences failed to reach significance when adjusted for multiple comparisons. No other significant association was found with clinical outcomes and polymorphisms in the five cytokine genes studied in this population.

Relationship between heart failure treatment and development of worsening renal function among hospitalized patients.

BACKGROUND: Among patients who are hospitalized with heart failure (HF), worsening renal function (WRF) is associated with worse outcomes. Whether treatment for HF contributes to WRF is unknown. In this study, we sought to assess whether acute treatment for patients who were hospitalized with HF contributes to WRF. METHODS: Data were collected in a nested case-control study on 382 subjects who were hospitalized with HF (191 patients with WRF, defined as a rise in serum creatinine level >26.5 micromol/L [0.3 mg/dL], and 191 control subjects). The association of medications, fluid intake/output, and weight with WRF was assessed. RESULTS: Calcium channel blocker (CCB) use and loop diuretic doses were higher in patients on the day before WRF (25% vs 10% for CCB; 199 +/- 195 mg vs 143 +/- 119 mg for loop diuretics; both P <.05). There were no significant differences in the fluid intake/output or weight changes in the 2 groups. Angiotensin-converting enzyme (ACE) inhibitor use was not associated with WRF. Other predictors of WRF included elevated creatinine level at admission, uncontrolled hypertension, and history of HF or diabetes mellitus. Higher hematocrit levels were associated with a lower risk. Vasodilator use was higher among patients on the day before WRF (46% vs 35%, P <.05), but was not an independent predictor in the multivariable analysis. CONCLUSIONS: Several medical strategies, including the use of CCBs and a higher dose of loop diuretics, but not ACE inhibitors, were associated with a higher risk of WRF. Although assessment of inhospital diuresis was limited, WRF could not be explained by greater fluid loss in these patients. Determining whether these interventions are responsible for WRF or are markers of higher risk requires further investigation.

Incidence, predictors at admission, and impact of worsening renal function among patients hospitalized with heart failure.

OBJECTIVES: The goal of this study was to determine the prevalence of worsening renal function (WRF) among hospitalized heart failure (HF) patients, clinical predictors of WRF, and hospital outcomes associated with WRF. BACKGROUND: Impaired renal function is associated with poor outcomes among chronic HF patients. METHODS: Chart reviews were performed on 1,004 consecutive patients admitted for a primary diagnosis of HF from 11 geographically diverse hospitals. Cox regression model analysis was used to identify independent predictors for WRF, defined as a rise in serum creatinine of >0.3 mg/dl (26.5 micromol/l). Bivariate analysis was used to determine associations of development of WRF with outcomes (in-hospital death, in-hospital complications, and length of stay). RESULTS: Among 1,004 HF patients studied, WRF developed in 27%. In the majority of cases, WRF occurred within three days of admission. History of HF or diabetes mellitus, admission creatinine > or =1.5 mg/dl (132.6 micromol/l), and systolic blood pressure >160 mm Hg were independently associated with higher risk of WRF. A point score based on these characteristics and their relative risk ratios predicted those at risk for WRF. Hospital deaths (adjusted risk ratio [ARR] 7.5; 95% confidence intervals [CI] 2.9, 19.3), complications (ARR 2.1; CI 1.5, 3.0), and length of hospitalizations >10 days (ARR 3.2, CI 2.2, 4.9) were greater among patients with WRF. CONCLUSIONS: Worsening renal function occurs frequently among hospitalized HF patients and is associated with significantly worse outcomes. Clinical characteristics available at hospital admission can be used to identify patients at increased risk for developing WRF.

The measurement of extravascular lung density with SPECT imaging and its relationship with ventilatory abnormalities in patients with congestive heart failure.

BACKGROUND: Patients with congestive heart failure (CHF) have increased ventilatory equivalent for carbon dioxide (Ve/VCO(2)), which may contribute to the symptom of exercise-induced hyperpnea. We have developed a technique in which simultaneous blood volume single photon emission computed tomography imaging and transmission tomography are used to measure extravascular lung density (ELD). We investigated the correlation between Ve/VCO(2) and ELD in patients with CHF. METHODS AND RESULTS: Thirteen patients with stable CHF and eleven control subjects were studied. Attenuation-corrected blood volume emission tomography was acquired with simultaneous transmission tomography to measure pulmonary blood volume and total lung density, respectively. Seven CHF patients underwent maximal exercise treadmill testing with online respiratory gas analysis. ELD was calculated as total lung density minus pulmonary blood volume. SPECT and transmission tomography were repeated immediately after exercise. CHF patients had significantly higher total lung density and ELD compared with normal subjects. No differences in pulmonary blood volume were observed. There was a significant inverse correlation between ELD and left ventricular ejection fraction at rest in CHF patients (r = -0.77, P <.001). A strong correlation was also found between post-exercise ELD and Ve/VCO(2) at peak exercise (r = 0.74, P =.008) and at anaerobic threshold (r = 0.67, P =.024). CONCLUSION: Patients with chronic CHF have increased ELD. The correlation between ELD and Ve/VCO(2) suggests that increased lung water may contribute to the ventilatory abnormalities seen in patients with CHF.