Incidental Pulmonary Nodules Reported on CT Abdominal Imaging: Frequency and Factors Affecting Inclusion in the Hospital Discharge Summary

Incidental imaging findings require an assessment of risk and clinical relevance, as well as consideration of further evaluation. Incidental findings are common on imaging obtained in the hospital, with pulmonary nodules being among the most frequent findings that may require additional evaluation. We conducted a retrospective study to determine the factors associated with documentation of incidental findings in the hospital discharge summary, using pulmonary nodules reported on abdominal computed tomography (CT) as an example of incidental findings with well-defined follow-up guidelines. Between January 1, 2012 and December 31, 2014, 7173 patients underwent in-patient abdominal CT without concurrent chest CT; of these patients, 62.2% were ≥60 years old, 50.6% were men, and 45.5% were current or former smokers. Incidental pulmonary nodules were reported in 402 patients (5.6%; 95% confidence interval [CI], 5.1%-6.2%). Based on nodule size, reported size stability, and patients' smoking status, 208 patients (2.9%; 95% CI, 2.5%-3.3%) required follow-up surveillance, per the 2005 Fleischner Society guidelines. Of these 208 patients, 48 (23%) received discharge summaries that included documentation of the incidental findings, with 34 summaries including a recommendation for nodule follow-up and 19 summaries including a time frame for repeat CT. Three factors were positively associated with the inclusion of the pulmonary nodule in the discharge summary: mention of the pulmonary nodule in the summary headings of the radiology report (P ≤ 0.001), radiologist recommendations for further surveillance (P ≤ 0.001), and medical discharging service (P = 0.016). These findings highlight the need for a multidisciplinary systems-based approach to incidental pulmonary nodule documentation and surveillance. Journal of Hospital Medicine 2017;12:454-457.

Bezlotoxumab: Could This be the Answer for Clostridium difficile Recurrence?

OBJECTIVE

To review the pharmacology, pharmacokinetics, efficacy, safety, and place in therapy of bezlotoxumab (BEZ), a novel monoclonal antibody against Clostridium difficile toxin B.

DATA SOURCES

A PubMed search was conducted for data between 1946 and April 2017 using MeSH terms bezlotoxumab, MK-6072, or MDX-1388 alone and the terms Clostridium difficile combined with monoclonal antibody or antitoxin.

STUDY SELECTION AND DATA EXTRACTION

The literature search was limited to English-language studies that described clinical efficacy, safety, and pharmacokinetics in humans and animals. Abstracts featuring prepublished data were also evaluated for inclusion.

DATA SYNTHESIS

BEZ is indicated for adult patients receiving standard-of-care (SoC) antibiotics for C difficile infection (CDI) to prevent future recurrence. Two phase III trials-MODIFY I (n = 1452) and MODIFY II (n = 1203)-demonstrated a 40% relative reduction in recurrent CDI (rCDI) with BEZ compared with placebo (16.5% vs 26.6%, P < 0.0001). The most common adverse drug events associated with BEZ were mild to moderate infusion-related reactions (10.3%).

CONCLUSIONS

In patients treated with SoC antibiotics, BEZ is effective in decreasing rCDI. BEZ has no apparent effect on treatment of an initial CDI episode. In light of increasing rates of CDI, BEZ is a promising option for preventing recurrent episodes. The greatest benefit has been demonstrated in high-risk patients, though the targeted patient population is yet to be defined.

Invitro Apramycin Activity against multidrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa

The in vitro activity of apramycin was compared to that of amikacin, gentamicin, and tobramycin against multidrug-resistant, extensively drug-resistant, and pandrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa. Apramycin demonstrated an MIC₅₀/MIC₉₀ of 8/32μg/ml for A. baumannii and 16/32μg/ml for P. aeruginosa. Only 2% of A. baumannii and P. aeruginosa had an MIC greater than an epidemiological cutoff value of 64μg/ml. In contrast, the MIC₅₀/MIC₉₀ for amikacin, gentamicin, and tobramycin were ≥64/>256μg/ml for A. baumannii with 57%, 95%, and 74% of isolates demonstrating resistance, respectively, and the MIC₅₀/MIC₉₀ were ≥8/256μg/ml for P. aeruginosa with 27%, 50%, and 57% of strains demonstrating resistance, respectively. Apramycin appears to offer promising in vitro activity against highly resistant pathogens. It therefore may warrant further pre-clinical study to assess potential for repurposing as a human therapeutic and relevance as a scaffold for further medicinal chemistry exploration.

Assessment of Fosfomycin for Complicated or Multidrug-Resistant Urinary Tract Infections: Patient Characteristics and Outcomes

BACKGROUND

Bacterial resistance among uropathogens is on the rise and has led to a decreased effectiveness of oral therapies. Fosfomycin tromethamine (fosfomycin) is indicated for uncomplicated urinary tract infections (UTIs) and displays in vitro activity against multidrug-resistant (MDR) isolates; however, clinical data assessing fosfomycin for the treatment of complicated or MDR UTIs are limited.

METHODS

We conducted a retrospective evaluation of patients who received ≥1 dose of fosfomycin between January 2009 and September 2015 for treatment of a UTI. Patients were included if they had a positive urine culture and documented signs/symptoms of a UTI.

RESULTS

Fifty-seven patients were included; 44 (77.2%) had complicated UTIs, 36 (63.2%) had MDR UTIs, and a total of 23 (40.4%) patients had a UTI that was both complicated and MDR. The majority of patients were female (66.7%) and elderly (median age, 79 years). Overall, the most common pathogens isolated were Escherichia coli (n = 28), Enterococcus spp. (n = 22), and Pseudomonas aeruginosa (n = 8). Twenty-eight patients (49.1%) were clinically evaluable; the preponderance achieved clinical success (96.4%). Fifteen out of 20 (75%) patients with repeat urine cultures had a microbiological cure.

CONCLUSIONS

This retrospective study adds to the limited literature exploring alternative therapies for complicated and MDR UTIs with results providing additional evidence that fosfomycin may be an effective oral option.

Clinical pathway for moderate to severe acute bacterial skin and skin structure infections from a US perspective: a roundtable discussion

This article was written with the aim to establish a consensus clinical pathway for long-acting lipoglycopeptide antibiotics such as oritavancin (Orbactiv®) and dalbavancin (Dalvance®) for the treatment of acute bacterial skin and skin structure infections (ABSSSI). Seven infectious diseases pharmacy specialists from a variety of facilities across the United States (US) participated in a roundtable discussion to consider the use of newer single-dose long-acting lipoglycopeptides, and integrate them into clinical pathways for ABSSSI. They identified two ways of treating with these drugs: first, to facilitate discharge from the hospital by switching from initial therapy (e.g., with intravenous (IV) vancomycin) and second, to avoid hospital admission altogether, since the product can be administered in several outpatient settings of care including the emergency department (ED), observation unit (OU) or outpatient infusion center. The participants used existing literature on classification and treatment of ABSSSI and their experience in the clinical setting as bases for their discussion and came to a consensus on the considerations for patient inclusion and exclusion as well as a pathway for outpatient treatment with long-acting lipoglycopeptides. As a result of the discussion, we concluded that the current treatment paradigm for ABSSSI is ripe for re-evaluation and reconfiguration in order to more closely align with the changing healthcare landscape. Hospital stakeholders are constantly searching for new strategies that can improve quality of care while simultaneously reducing overall expenses. The availability of single-dose long-acting lipoglycopeptides is an opportunity to opt for lower-cost outpatient treatment of appropriate ABSSSI patients. This article proposes the inclusion and exclusion considerations, along with a consensus treatment pathway, that could provide a solid foundation for facilities to construct and adapt their own effective clinical pathways for ABSSSI.

Evaluation of mobilized peripheral blood CD34(+) cells from patients with severe coronary artery disease as a source of endothelial progenitor cells

BACKGROUND AIMS

The distinction between hematopoietic stem cells (HSC) and endothelial progenitor cells (EPC) is poorly defined. Co-expression of CD34 antigen with vascular endothelial growth factor (VEGF) receptor (VEGFR2) is currently used to define EPC ( 1 ).

METHODS

We evaluated the phenotypic and genomic characteristics of peripheral blood-derived CD34(+) cells in 22 granulocyte-colony-stimulating factor (G-CSF)-mobilized patients with severe coronary artery disease and assessed the influence of cell selection and storage on CD34(+) cell characteristics.

RESULTS

The median CD34(+) cell contents in the products before and after enrichment with the Isolex 300i Magnetic Cell Selection System were 0.2% and 82.5%, respectively. Cell-cycle analysis showed that 80% of CD34(+) cells were in G0 stage; 70% of the isolated CD34(+) cells co-expressed CD133, a marker for more immature progenitors. However, less than 5% of the isolated CD34(+) cells co-expressed the notch receptor Jagged-1 (CD339) and only 2% of the isolated CD34(+) population were positive for VEGFR2 (CD309). Molecular assessment of the isolated CD34(+) cells demonstrated extremely low expression of VEGFR2 and endothelial nitric oxide synthase (eNOS) and high expression of VEGF-A. Overnight storage at 4 degrees C did not significantly affect CD34(+) cell counts and viability. Storage in liquid nitrogen for 7 weeks did not affect the percentage of CD34(+) cells but was associated with a 26% drop in cell viability.

CONCLUSIONS

We have demonstrated that the majority of isolated CD34(+) cells consist of immature and quiescent cells that lack prototypic markers of EPC. High VEGF-A gene expression might be one of the mechanisms for CD34(+) cell-induced angiogenesis.

Clinically significant adverse events from a drug interaction between quetiapine and atazanavir-ritonavir in two patients

Clinicians caring for patients infected with the human immunodeficiency virus (HIV) and diagnosed with psychiatric comorbidities must be aware of potential drug-drug interactions, particularly with protease inhibitor-based antiretroviral therapy. Although possible interactions can be predicted based on a drug's pharmacokinetic parameters, the clinical significance is often unknown. We describe two patients who experienced serious quetiapine adverse effects potentially mediated through an interaction with ritonavir-boosted atazanavir. The first patient was a 57-year-old man with HIV and bipolar disease who developed rapid and severe weight gain when quetiapine was added to a stable atazanavir-ritonavir-based antiretroviral regimen. After the patient discontinued both quetiapine and ritonavir, his weight returned to its baseline value. The second patient was a 32-year-old woman with HIV, anxiety disorder, and a history of intravenous drug abuse who developed increased sedation and mental confusion when an atazanavir-ritonavir-based antiretroviral regimen was added to her stable antianxiety drug regimen, which included quetiapine. Her symptoms resolved promptly after discontinuation of the quetiapine. Use of the Naranjo adverse drug reaction probability scale indicated that the adverse effects experienced by the two patients were possibly related and probably related, respectively, to an interaction between quetiapine and atazanavir-ritonavir. Quetiapine is primarily metabolized by cytochrome P450 (CYP) 3A4, and ritonavir is a potent inhibitor of CYP3A4. Thus, it is reasonable to theorize that quetiapine concentrations will increase when these drugs are used concurrently, which would be the likely cause of the toxicities in these two patients. To our knowledge, these are the first published reports of a clinically significant interaction between atazanavir-ritonavir and quetiapine. Clinicians should be aware of the potential for this interaction, and extreme caution should be used when prescribing quetiapine and other atypical antipsychotic agents in HIV-positive patients who are receiving antiretroviral therapy.

Flea blood feeding patterns in cats treated with oral nitenpyram and the topical insecticides imidacloprid, fipronil and selamectin

A series of studies was conducted to determine the effect of systemically and topically active insecticides on blood consumption by fleas (Ctenocephalides felis). Infestations were conducted by placing fleas into plexi-glass chambers attached to the lateral rib cage of domestic short-hair cats. After pre-defined periods, fleas and flea feces were extracted using vacuum aspiration and spectrophotometrically analyzed for hemoglobin using Drabkin's reagent. To determine how rapidly nitenpyram kills actively feeding fleas, a single oral treatment was administered 24h after infestation. To determine the effect of nitenpyram on blood consumption of newly acquired fleas, cats were infested with fleas 1h post-treatment and fleas and flea feces from both studies were extracted at 15, 30, 60, 120, 240 and 480min post-treatment or post-infestation. To compare the effects of topically versus systemically active insecticides, 20 cats each with 2 chambers attached, were randomly allocated among groups and were infested with fleas 1h after each of 4 nitenpyram treatments, or at 7, 14, 21 and 28 days after a single application of commercial spot-on formulations of fipronil, imidacloprid or selamectin. Infestations were also completed for untreated (control) cats. Twenty-four hours after infestation, fleas and flea feces were removed for host blood quantification. If at any time, flea blood consumption in a treated group did not significantly differ from that of fleas infesting controls, that treatment group was withdrawn from the study. Nitenpyram effects on actively feeding fleas were first observed at 60min post-dosing when 38% of fleas were dead or moribund, and at 240min 100% were dead or moribund. Nitenpyram produced a significant reduction in flea blood consumption (p<0.05), which appeared to cease 15min after infestation. For the treatment comparisons, significantly more (p<0.05) blood was consumed by fleas taken from imidacloprid and fipronil-treated cats than from the nitenpyram or selamectin groups. Only on nitenpyram- or selamectin-treated cats were there significant reductions (p<0.05) in flea blood consumption on days 21 and 28, with significant difference (p>0.05) between these two groups on day 28. In this study systemically acting insecticides such as nitenpyram, and the topically applied but systemically active insecticide selamectin, were more effective in interfering with flea blood feeding than were imidacloprid and fipronil.

Darunavir: a nonpeptidic antiretroviral protease inhibitor

BACKGROUND

Protease inhibitors were a major therapeutic breakthrough in the mid-1990s for the treatment of HIV infection, which resulted in improved life expectancy for patients who had failed previous therapies. With time and evolution of the virus, however, there is a new population of patients with treatment-resistant disease and few treatment options. Darunavir is a synthetic nonpeptidic analogue of amprenavir with enhanced activity against resistant virus that became available in 2006.

OBJECTIVES

The purpose of this review was to describe the clinical pharmacology, pharmacokinetic and pharmacodynamic properties, and clinical efficacy of darunavir. Also discussed are the published clinical experience with darunavir, its adverse events, drug interactions, pharmacoeconomics, and dosing and administration.

METHODS

A MEDLINE and EMBASE search (English-language only) was performed from January 1996 through April 2007 using the key words darunavir and TMC114. Abstracts from relevant scientific meetings were searched for the years 2000 through 2007. Additionally, the US Food and Drug Administration Web site was accessed to review the new drug application summary and data presented therein.

RESULTS

Darunavir was found to maintain antiretroviral activity against HIV with protease inhibitor mutations in 6 studies. Clinical efficacy and safety data are limited to 4 controlled and 2 uncontrolled trials. In 2 large Phase IIb clinical studies, viral suppression at 48 weeks to undetectable levels in heavily pretreated patients was achieved in 45% of patients compared with 10% of patients in the control group (P < 0.001). The addition of enfuvirtide enhanced this response rate to 58% compared with 11% of the patients who did not receive enfuvirtide (P < 0.001). Gastrointestinal symptoms, nausea, and headache were the most commonly reported events.

CONCLUSIONS

Darunavir has improved activity against resistant HIV isolates in patients with few treatment choices, particularly when enfuvirtide is added. The safety profile of darunavir is comparable to other protease inhibitors based on early data.

Phase I dose-escalation study of novel oral multi-target tumor growth inhibitor (MTGI) ZK 304709 administered daily for 7 days of a 21-day cycle to patients with advanced solid tumors

2073

Background: ZK304709 is a novel MTGI that selectively inhibits activity of Cyclin Dependent Kinases (CDKs) 1, 2, 4, 7, 9, and the tyrosine kinase activity of VEGF-R 1, 2, 3 and PDGF-βR. Methods: Adult patients (pts) with a good performance status (WHO PS ≤2) and a histologically or cytologically confirmed relapsed/refractory solid tumor were eligible. ZK304709 is administered, as a monotherapy, orally on days 1–7 of a 21-day cycle to fasting patients at a starting dose of 15 mg qd. Dose escalation has ranged from 33% - 100% of prior dose, depending on occurrence of drug-related toxicity ≥ grade (gr) 2 (CTC v2.0). Between 3 and 7 patients are to be enrolled per dose level, depending on DLTs that are observed. The primary objective is determination of the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT) of ZK304709. Secondary objectives include tolerability, pharmacokinetic (PK) profile, and preliminary efficacy. Results: Interim results are available for 22 pts (15 M/7 F, median age 60.5 yrs; range 37–71) treated with ZK304709 at 6 dose levels (15 - 180 mg qd). Patients completed a median of 2 cycles (range 0–8). Common AEs were nausea, vomiting, diarrhea, and lethargy. Two DLT were observed: supraventricular tachycardia and vomiting, but the MTD was not reached. The PK profile shows rapid absorption, with a Tmax of 2–4 hrs, and a dose-dependent increase in systemic exposure over the 15–90 mg dose range. Disease stabilization for ≥4 cycles has been observed. Conclusions: ZK304709 is rapidly absorbed and has been tolerated on this schedule at doses up to 180 mg qd. The MTD has not been reached, and enrolment is ongoing. These preliminary data demonstrate that oral delivery on this schedule of an agent that inhibits both cell cycle and angiogenesis is feasible.

[Table: see text]

Phase I dose-escalation study of ZK 304709, an oral multi-target tumor growth inhibitor (MTGI), administered for 14 days of a 28-day cycle

2076

Background: ZK 304709 is a novel oral MTGI that induces cell cycle arrest and inhibits tumour angiogenesis by selectively inhibiting Cyclin Dependent Kinases (CDKs) 1, 2, 4, 7 and 9,VEGF-R 1, 2 and 3, and PDGF-Rβ tyrosine kinases. Methods: Adult patients (pts) (WHO PS ≤2) with a histologically or cytologically confirmed solid tumor, resistant or refractory to conventional therapy, were eligible. ZK304709 was administered orally, once daily, at a 15 mg starting dose, on days 1–14 of a 28-day cycle, then escalated by 33–100% depending on incidence of drug-related toxicity ≥ grade (gr) 2 (CTC v2.0). At least 3 pts were treated at each dose level. The primary objective was to identify the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT). Secondary objectives were to determine the tolerability, pharmacokinetic (PK) profile, and preliminary efficacy. Results: Interim results were available for 24 pts (19 M/5 F; median age 56.5) at 5 dose levels (15–120 mg qd). Pts received a median of 2 cycles (range 0–10). Common drug related toxicities were nausea, vomiting, and fatigue. Two DLT were observed: dizziness and hypertension. However, the MTD has yet to be established. The PK profile for dose levels up to 90 mg demonstrated rapid absorption and a dose-dependent increase of exposure and Cmax. Disease stabilization for ≥4 cycles has been observed. Conclusions: ZK 304709 was rapidly absorbed and has been tolerated on this schedule at up to 120 mg qd. The MTD has not been reached and enrolment is ongoing. These preliminary data demonstrate that oral delivery on this schedule of an agent that inhibits both cell cycle and angiogenesis is feasible.

[Table: see text]