Decreased Efficacy (decreased + efficacy)

Distribution by Scientific Domains


Selected Abstracts


Factors Limiting the Efficacy of Hydrogen Peroxide Washes for Decontamination of Apples Containing Escherichia coli

JOURNAL OF FOOD SCIENCE, Issue 3 2000
G.M. Sapers
ABSTRACT: Factors limiting efficacy of H2O2 washes and alternative decontamination strategies were investigated with Golden Delicious apples, inoculated with nonpathogenic Escherichia coli. Post-treatment rinsing decreased efficacy by eliminating residual H2O2. A 2-stage wash incorporating a rinse to remove surfactant residues prior to H2O2 application was developed. Rapid attachment of E. coli to apples prevented effective removal by washing with water. Surviving E. coli following a 5% H2O2 wash were concentrated in stem and calyx areas. Survival was independent of the time interval between inoculation and washing. E. coli inoculation of punctured apple surfaces resulted in growth at 20 °C and greater survival after washing with 5% H2O2. Improved decontamination methods are needed. [source]


Opioids and the Management of Chronic Severe Pain in the Elderly: Consensus Statement of an International Expert Panel with Focus on the Six Clinically Most Often Used World Health Organization step III Opioids (Buprenorphine, Fentanyl, Hydromorphone, Methadone, Morphine, Oxycodone)

PAIN PRACTICE, Issue 4 2008
Joseph Pergolizzi MD
,,Abstract Summary of consensus: 1.,The use of opioids in cancer pain:, The criteria for selecting analgesics for pain treatment in the elderly include, but are not limited to, overall efficacy, overall side-effect profile, onset of action, drug interactions, abuse potential, and practical issues, such as cost and availability of the drug, as well as the severity and type of pain (nociceptive, acute/chronic, etc.). At any given time, the order of choice in the decision-making process can change. This consensus is based on evidence-based literature (extended data are not included and chronic, extended-release opioids are not covered). There are various driving factors relating to prescribing medication, including availability of the compound and cost, which may, at times, be the main driving factor. The transdermal formulation of buprenorphine is available in most European countries, particularly those with high opioid usage, with the exception of France; however, the availability of the sublingual formulation of buprenorphine in Europe is limited, as it is marketed in only a few countries, including Germany and Belgium. The opioid patch is experimental at present in U.S.A. and the sublingual formulation has dispensing restrictions, therefore, its use is limited. It is evident that the population pyramid is upturned. Globally, there is going to be an older population that needs to be cared for in the future. This older population has expectations in life, in that a retiree is no longer an individual who decreases their lifestyle activities. The "baby-boomers" in their 60s and 70s are "baby zoomers"; they want to have a functional active lifestyle. They are willing to make trade-offs regarding treatment choices and understand that they may experience pain, providing that can have increased quality of life and functionality. Therefore, comorbidities,including cancer and noncancer pain, osteoarthritis, rheumatoid arthritis, and postherpetic neuralgia,and patient functional status need to be taken carefully into account when addressing pain in the elderly. World Health Organization step III opioids are the mainstay of pain treatment for cancer patients and morphine has been the most commonly used for decades. In general, high level evidence data (Ib or IIb) exist, although many studies have included only few patients. Based on these studies, all opioids are considered effective in cancer pain management (although parts of cancer pain are not or only partially opioid sensitive), but no well-designed specific studies in the elderly cancer patient are available. Of the 2 opioids that are available in transdermal formulation,fentanyl and buprenorphine,fentanyl is the most investigated, but based on the published data both seem to be effective, with low toxicity and good tolerability profiles, especially at low doses. 2.,The use of opioids in noncancer-related pain:, Evidence is growing that opioids are efficacious in noncancer pain (treatment data mostly level Ib or IIb), but need individual dose titration and consideration of the respective tolerability profiles. Again no specific studies in the elderly have been performed, but it can be concluded that opioids have shown efficacy in noncancer pain, which is often due to diseases typical for an elderly population. When it is not clear which drugs and which regimes are superior in terms of maintaining analgesic efficacy, the appropriate drug should be chosen based on safety and tolerability considerations. Evidence-based medicine, which has been incorporated into best clinical practice guidelines, should serve as a foundation for the decision-making processes in patient care; however, in practice, the art of medicine is realized when we individualize care to the patient. This strikes a balance between the evidence-based medicine and anecdotal experience. Factual recommendations and expert opinion both have a value when applying guidelines in clinical practice. 3.,The use of opioids in neuropathic pain:, The role of opioids in neuropathic pain has been under debate in the past but is nowadays more and more accepted; however, higher opioid doses are often needed for neuropathic pain than for nociceptive pain. Most of the treatment data are level II or III, and suggest that incorporation of opioids earlier on might be beneficial. Buprenorphine shows a distinct benefit in improving neuropathic pain symptoms, which is considered a result of its specific pharmacological profile. 4.,The use of opioids in elderly patients with impaired hepatic and renal function:, Functional impairment of excretory organs is common in the elderly, especially with respect to renal function. For all opioids except buprenorphine, half-life of the active drug and metabolites is increased in the elderly and in patients with renal dysfunction. It is, therefore, recommended that,except for buprenorphine,doses be reduced, a longer time interval be used between doses, and creatinine clearance be monitored. Thus, buprenorphine appears to be the top-line choice for opioid treatment in the elderly. 5.,Opioids and respiratory depression:, Respiratory depression is a significant threat for opioid-treated patients with underlying pulmonary condition or receiving concomitant central nervous system (CNS) drugs associated with hypoventilation. Not all opioids show equal effects on respiratory depression: buprenorphine is the only opioid demonstrating a ceiling for respiratory depression when used without other CNS depressants. The different features of opioids regarding respiratory effects should be considered when treating patients at risk for respiratory problems, therefore careful dosing must be maintained. 6.,Opioids and immunosuppression:, Age is related to a gradual decline in the immune system: immunosenescence, which is associated with increased morbidity and mortality from infectious diseases, autoimmune diseases, and cancer, and decreased efficacy of immunotherapy, such as vaccination. The clinical relevance of the immunosuppressant effects of opioids in the elderly is not fully understood, and pain itself may also cause immunosuppression. Providing adequate analgesia can be achieved without significant adverse events, opioids with minimal immunosuppressive characteristics should be used in the elderly. The immunosuppressive effects of most opioids are poorly described and this is one of the problems in assessing true effect of the opioid spectrum, but there is some indication that higher doses of opioids correlate with increased immunosuppressant effects. Taking into consideration all the very limited available evidence from preclinical and clinical work, buprenorphine can be recommended, while morphine and fentanyl cannot. 7.,Safety and tolerability profile of opioids:, The adverse event profile varies greatly between opioids. As the consequences of adverse events in the elderly can be serious, agents should be used that have a good tolerability profile (especially regarding CNS and gastrointestinal effects) and that are as safe as possible in overdose especially regarding effects on respiration. Slow dose titration helps to reduce the incidence of typical initial adverse events such as nausea and vomiting. Sustained release preparations, including transdermal formulations, increase patient compliance.,, [source]


FROM CRISIS TO CUMULATIVE EFFECTS: FOOD SECURITY CHALLENGES IN ALASKA

ANNALS OF ANTHROPOLOGICAL PRACTICE, Issue 1 2009
David V. Fazzino
Recent increases in the price of fuel in rural Alaska, coupled with high prices of grocery store foods and decreased efficacy of hunting and fishing have led to a food crisis in many regions of rural Alaska. In the summer of 2008 it was predicted that these events would lead to an upswing in the number of individuals migrating to urban areas of Alaska, putting additional stress on the already dwindling resources of food assistance providers. Through discussions with food assistance providers in Fairbanks, Alaska, a research program was designed to assess how well recent migrants were able to meet their food needs. In total 39 individuals were interviewed in November and December 2008, using face-to-face, semistructured interviews. This article discusses a smaller subset of the overall interviews, namely the responses of Natives who currently live in Fairbanks, Alaska. Further, this article informs understandings of "crisis" in the global sense, highlighting the importance of placing "crises" into the larger context of cumulative effects which are long-term and differentially distributed, rather than treating them as discrete and individually mitigatable events. [source]


Dronedarone: Current Evidence and Future Questions

CARDIOVASCULAR THERAPEUTICS, Issue 1 2010
Jeremy A. Schafer
Atrial fibrillation (AF) is the most common sustained arrhythmia, affecting more than 2.2 million Americans. ACC/AHA/ESC guidelines for the management of patients with AF recommend amiodarone for maintaining sinus rhythm. Dronedarone is a derivative of amiodarone indicated for the treatment of AF. To provide an overview of dronedarone with a focus on the phase III trials and discuss unresolved questions of dronedarone. A literature search was conducted via the PubMed database using the keyword "dronedarone." Search was limited to human trials in english. The FDA website was searched for briefing documents and subcommittee meetings on dronedarone. Clinicaltrials.gov was searched with the keyword dronedarone for upcoming or unpublished clinical trials. Five phase III trials are available for dronedarone: ANDROMEDA, EURIDIS/ADONIS, ATHENA, ERATO, and DIONYSIS. EURIDIS/ADONIS and ATHENA demonstrated a reduction AF recurrence with dronedarone compared to placebo. The ANDROMEDA trial recruited patients with recent hospitalization for heart failure and was terminated due to an excess of deaths in the dronedarone group. The DIONYSIS trial was a comparative effectiveness trial that demonstrated less efficacy for dronedarone but improved tolerability compared to amiodarone. Dronedarone represents an option in the management of AF in select patients. Dronedarone is not appropriate in patients with recently decompensated heart failure or those treated with strong CYP3A4 inhibitors or medications prolonging the QT interval. Dronedarone appears to have improved tolerability at the expense of decreased efficacy when compared to amiodarone. Questions remain on the long-term safety, use in patients with heart failure, retreatment after dronedarone or amiodarone failure, and comparative efficacy with a rate control strategy. [source]


Discovery of Selective Luteinizing Hormone Receptor Agonists Using the Bivalent Ligand Method

CHEMMEDCHEM, Issue 7 2009
Kimberly
Abstract Two series of dimeric ligands for a G-protein-coupled receptor were prepared that differ by the interconnecting spacer system. Biological evaluation revealed that both dimeric series exhibit unique biological properties relative to their monomeric counterparts. The luteinizing hormone receptor (LHR), the follicle-stimulating hormone receptor (FSHR), and the thyroid-stimulating hormone receptor (TSHR) belong to the glycoprotein hormone receptor (GpHR) family. A prominent feature of all endogenous glycoprotein ligands is that they share an identical ,,subunit and acquire their selectivity from the unique ,,subunit. Recent developments in pro-fertility research have led to the discovery of several low-molecular-weight agonists for the luteinizing hormone/choriogonadotropin receptor that bind to the transmembrane (TM) region of the LHR. Interestingly, some of these agonists are also able to activate the FSHR. Several research groups have shown that ligand dimerization presents a powerful tool to increase the subtype selectivity for structurally related G-protein-coupled receptors. In this work, we applied the dimerization strategy to GpHRs and explored the effect on receptors with closely related TM regions. Two series of dimeric ligands were prepared that differ in the interconnecting spacer system. Biological evaluation revealed that both series exhibit unique selectivity properties for the LHR, originating from either decreased potency or a decreased efficacy toward the FSHR. [source]


Activity of ciprofloxacin and levofloxacin in experimental pneumonia caused by Klebsiella pneumoniae deficient in porins, expressing active efflux and producing QnrA1

CLINICAL MICROBIOLOGY AND INFECTION, Issue 7 2008
J. M. Rodríguez-Martínez
Abstract The objective of this study was to evaluate the activities of ciprofloxacin and levofloxacin in a murine model of pneumonia caused by Klebsiella pneumoniae C2 (with altered GyrA, deficient in porins and expressing active efflux of quinolones) and the transconjugant C2pMG252 derived from it and expressing the qnrA1 determinant. MICs and MBCs of the two quinolones were determined according to CLSI guidelines. Time-kill curves (at 1× and 4× MIC) were also performed to assess bactericidal activity. An experimental model of pneumonia in mice was evaluated. Groups of 15 mice were infected with either strain and treated with ciprofloxacin (80 mg/kg/day) or levofloxacin (100 mg/kg/day). Control non-treated animals were also evaluated. In the case of strain C2, log10 CFU/g of lung in non-treated animals was 9.16 ± 2.16. This value was reduced to 3.53 ± 1.04 (p <0.001) and 3.38 ± 0.46 (p <0.001) in animals treated with ciprofloxacin or levofloxacin, respectively. Percentages of surviving mice were 26.7% (control group) and 100% (both ciprofloxacin and levofloxacin; p <0.001 vs. controls). Bacterial counts (log10 CFU/g) in lungs of animals infected with strain C2pMG252 were 9.65 ± 2.49 in non-treated animals and 7.74 ± 2.67 and 7.57 ± 3.84 for those treated with ciprofloxacin or levofloxacin, respectively (p >0.05 vs. control group). Of non-treated animals infected with strain C2pMG252, 14.3% survived. Ciprofloxacin and levofloxacin improved the survival in these mice (53.3% for both antimicrobials, p 0.03). In conclusion, the expression of qnrA1 in K. pneumoniae with additional mechanisms of resistance causes decreased efficacy of fluoroquinolones in a pneumonia model in mice. [source]