Cefsulodin sodium therapy in cystic fibrosis patients

Intravenous antibiotics for pulmonary exacerbations in people with cystic fibrosis

BACKGROUND

Cystic fibrosis is a multi-system disease characterised by the production of thick secretions causing recurrent pulmonary infection, often with unusual bacteria. Intravenous antibiotics are commonly used in the treatment of acute deteriorations in symptoms (pulmonary exacerbations); however, recently the assumption that exacerbations are due to increases in bacterial burden has been questioned.

OBJECTIVES

To establish if intravenous antibiotics for the treatment of pulmonary exacerbations in people with cystic fibrosis improve short- and long-term clinical outcomes.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews and ongoing trials registers.Date of last search of Cochrane trials register: 27 July 2015.

SELECTION CRITERIA

Randomised controlled trials and the first treatment cycle of cross-over studies comparing intravenous antibiotics (given alone or in an antibiotic combination) with placebo, inhaled or oral antibiotics for people with cystic fibrosis experiencing a pulmonary exacerbation.

DATA COLLECTION AND ANALYSIS

The authors assessed studies for eligibility and risk of bias and extracted data.

MAIN RESULTS

We included 40 studies involving 1717 participants. The quality of the included studies was largely poor and, with a few exceptions, these comprised of mainly small, inadequately reported studies.When comparing treatment with a single antibiotic to a combined antibiotic regimen, those participants receiving a combination of antibiotics experienced a greater improvement in lung function when considered as a whole group across a number of different measurements of lung function, but with very low quality evidence. When limited to the four placebo-controlled studies (n = 214), no difference was observed, again with very low quality evidence. With regard to the review's remaining primary outcomes, there was no effect upon time to next exacerbation and no studies in any comparison reported on quality of life. There were no effects on the secondary outcomes weight or adverse effects. When comparing specific antibiotic combinations there were no significant differences between groups on any measure. In the comparisons between intravenous and nebulised antibiotic or oral antibiotic (low quality evidence), there were no significant differences between groups on any measure. No studies in any comparison reported on quality of life.

AUTHORS' CONCLUSIONS

The quality of evidence comparing intravenous antibiotics with placebo is poor. No specific antibiotic combination can be considered to be superior to any other, and neither is there evidence showing that the intravenous route is superior to the inhaled or oral routes. There remains a need to understand host-bacteria interactions and in particular to understand why many people fail to fully respond to treatment.

High-throughput screens for small-molecule inhibitors of Pseudomonas aeruginosa biofilm development

Pseudomonas aeruginosa is both a model biofilm-forming organism and an opportunistic pathogen responsible for chronic lung infections in cystic fibrosis (CF) patients and infections in burn patients, among other maladies. Here we describe the development of an efficient high-throughput screen to identify small-molecule modulators of biofilm formation. This screen has been run with 66,095 compounds to identify those that prevent biofilm formation without affecting planktonic bacterial growth. The screen is a luminescence-based attachment assay that has been validated with several strains of P. aeruginosa and compared to a well-established but low-throughput crystal violet staining biofilm assay. P. aeruginosa strain PAO1 was selected for use in the screen both because it forms robust biofilms and because genetic information and tools are available for the organism. The attachment-inhibited mutant, strain PAO1 DeltafliC, was used as a screening-positive control. We have also developed and validated a complementary biofilm detachment assay that can be used as an alternative primary screen or secondary screen for the attachment screening-positive compounds. We have determined the potencies of 61 compounds against biofilm attachment and have identified 30 compounds that fall into different structural classes as biofilm attachment inhibitors with 50% effective concentrations of less than 20 microM. These small-molecule inhibitors could lead to the identification of their relevant biofilm targets or potential therapeutics for P. aeruginosa infections.

Approaches to the Treatment of Initial Pseudomonas aeruginosa Infection in Children Who Have Cystic Fibrosis

Pseudomonas aeruginosa remains an important cause of pulmonary disease in patients who have cystic fibrosis. The development of antimicrobial therapy directed against this organism has resulted in the preservation of lung function and improved longevity. Efficacy has been demonstrated with agents administered via parenteral, inhaled, and oral routes. The optimal antibiotic regimen remains unclear. There is an active effort to use randomized, controlled clinical trials to rigorously test effective antibiotic for the eradication of P aeruginosa in young children or at least to delay the establishment of chronic infection.

Randomized trial of ceftazidime versus placebo in the management of acute respiratory exacerbations in patients with cystic fibrosis

A randomized trial of ceftazidime versus placebo was conducted in patients with cystic fibrosis hospitalized for acute respiratory exacerbations. Patients 12 years of age or older were included if they had mild to moderately severe illness according to the following criteria: erythrocyte sedimentation rate less than or equal to 50 mm/hr and less than three other abnormalities (leukocyte count greater than or equal to 15,000/microliter, pulse greater than or equal to 100 beats/min, respirations greater than or equal to 30/min, or temperature greater than or equal to 38.5 degrees C). In all 16 episodes treated with ceftazidime, the patients were rated improved in comparison with 10 of 12 patients treated with placebo. Three placebo-treated patients dropped out of the study within 3 to 5 days because they wanted antibiotic therapy. None of the 15 placebo-treated patients showed clinical deterioration. There were no significant differences in rate of improvement of symptom score, weight gain, or pulmonary function between the two treatment groups. There was no difference in the course during the 6 to 24 months after the study period. Intravenous antibiotics are not essential in the management of all acute respiratory exacerbations of mild to moderate severity in patients with cystic fibrosis.

High dose treatment with antibiotics in cystic fibrosis--a reappraisal with special reference to the pharmacokinetics of beta-lactams and new fluoroquinolones in adult CF-patients

In this review we analyzed the pharmacokinetic basis for high dose treatment with antibiotics of patients with cystic fibrosis. Both our results and those from other well designed pharmacokinetic studies do not support the view that low blood levels of antibacterials are a common feature of CF. We were unable to detect a decrease in absorption, nor could we find evidence for enhanced elimination of antibacterials in CF. Both these factors have been considered responsible for reducing the plasma (and tissue) levels of antibiotics. Most recent studies on kidney function are in agreement with these findings, since neither inulin nor creatinine clearance differ between CF-patients and healthy volunteers. In contrast to previous discussion, the volume of distribution (Vdss) was not elevated for any compound. The rational of weight correction of volume terms like Vdss or total clearance has never been clearly demonstrated and should therefore not be used without prior proof of relevance. Since the variability of pharmacokinetic parameters of antibiotics in CF-patients may be considerable, we suggest that a dose increase of 20-30% may be justified, but cannot agree with two to fourfold increases in dosage as previously proposed and applied in many CF-centers. Until more findings become available for non-adult CF-patients, these conclusions are only valid for adult CF-patients.

Treatment of respiratory tract infections with cephalosporin antibiotics

Infections of the respiratory tract are among the most common causes for antibiotic prescribing. Their diagnosis within the community is generally limited to clinical criteria, and microbiological information is frequently lacking. Hospitalised patients with respiratory tract infections are more likely to undergo diagnostic sampling, but difficulties remain in reliably defining a microbial aetiology, thereby providing a confident basis for antibiotic selection. In considering the role of the cephalosporins in the treatment of respiratory tract infections, over 500 published articles have been reviewed. The pharmacokinetic considerations are discussed and the limitations of existing methodology are emphasised. Individual agents are reviewed by site of sepsis and conclusions are drawn from both comparative and non-comparative studies and in relation to currently recommended regimens. Although oral cephalosporins are widely used to treat upper respiratory tract infections, none is considered ideal, especially where Haemophilus influenzae is pathogenic. In the case of lower respiratory tract infections the beta-lactamase stable parenteral cephalosporins have become widely used to treat pneumonia in hospitalised patients, especially where Gram-negative enteric bacilli are of aetiological importance. However, the lack of activity of these drugs against Legionella spp., Mycoplasma pneumoniae and Coxiella burnetii must be emphasised. Another area of increasing use is in the treatment of infective exacerbations in patients suffering from cystic fibrosis of the lungs where Pseudomonas aeruginosa is pathogenic; ceftazidime in particular has proved a useful alternative to earlier antipseudomonal penicillin antibiotics.

Cefsulodin

The chemistry, microbiology, pharmacokinetics, adverse reactions, and clinical indications for cefsulodin are reviewed and compared to ceftazidime and cefoperazone. Cefsulodin is a narrow-spectrum, third-generation cephalosporin with activity virtually restricted to Pseudomonas aeruginosa. Cefsulodin is eliminated renally and has a serum half-life similar to ceftazidime and cefoperazone. Cefsulodin appears to be well tolerated and relatively free of any significant toxicity except for nausea and vomiting, which appear to be related to the infusion rate. Cefsulodin may be beneficial in those rare clinical situations where an infection is caused by a sensitive isolate of P. aeruginosa known to be resistant to the other antipseudomonal cephalosporins, and/or the avoidance of an aminoglycoside antibiotic is desired. However, its empiric use is to be discouraged.

Occurrence and antimicrobial susceptibility of gram-negative nonfermentative bacilli in cystic fibrosis patients

Isolation of nonfermentative gram-negative bacilli (other than Pseudomonas aeruginosa) from respiratory tract cultures of cystic fibrosis (CF) patients has increased in recent years. Species recovered include Pseudomonas cepacia, P. maltophilia, P. fluorescens/putida, P. alcaligenes, P. pseudoalcaligenes, P. stutzeri, Acinetobacter spp., Achromobacter xylosoxidans, Flavobacterium spp., and CDC groups IVe and Ve. Although colonization with most of these organisms is sporadic, P. cepacia (and to a lesser extent, P. maltophilia) is usually isolated consistently, and can be associated with significant clinical deterioration. Occurrence of P. cepacia in CF respiratory tract cultures obtained close to the time of death rose nearly ten-fold from 1979 to 1982. Strains representing all nonfermentative gram-negative species encountered were assayed for susceptibility to 17 newer antimicrobial agents. Ceftazidime, n-formimidoyl thienamycin, and aztreonam were most active; cefsulodin, ceforanide, and ceftriaxone were not active against these isolates.

Effect of aztreonam in combination with azlocillin or piperacillin on Pseudomonas aeruginosa

Aztreonam, a synthetic monobactam antimicrobial agent specifically active against aerobic, gram-negative microorganisms, was studied in combination with the extended-spectrum penicillins azlocillin and piperacillin against 46 strains of Pseudomonas aeruginosa. Of these strains, 4.3% were synergistically inhibited, and 19.7% showed evidence for an additive effect of the antibiotics. All other strains showed indifference. The addition of cefoxitin to these combinations increased the MICs of azlocillin and piperacillin by two to three tubes, whereas zero- to one-tube increases were noted for aztreonam MICs. Attempts to block cefoxitin-induced beta-lactamase production by using clindamycin were unsuccessful even at high clindamycin concentrations.