Randomized comparative trial with ampicillin/sulbactam versus cefamandole in the therapy of community acquired pneumonia

Population Pharmacokinetics and Dosing Simulations of Ampicillin and Sulbactam in Hospitalised Adult Patients

BACKGROUND

The pharmacokinetic variability of ampicillin-sulbactam in adults has not been extensively described, particularly in patients with a reduced renal function (i.e., < 60 mL/min).

OBJECTIVE

This study investigated the population pharmacokinetics of ampicillin and sulbactam in patients with a wide range of renal functions and sought to define dosing approaches that have a high likelihood for optimising drug exposure.

METHODS

Serial blood samples were collected from 16 adult patients receiving intravenous ampicillin-sulbactam in general wards. Total ampicillin and sulbactam concentrations were measured by chromatographic assay and pharmacokinetic parameters were estimated using Pmetrics^®. Monte Carlo simulations were used to evaluate the probability of target attainment (PTA) of free ampicillin and sulbactam concentrations exceeding the minimum inhibitory concentration (MIC) for 60% and 100% of the dosing interval. Fractional target attainment (FTA) was calculated against MIC distributions of common hospital pathogens. A threshold of ≥ 90% and ≥ 95% was used to define both optimal PTA and FTA, respectively.

RESULTS

The median (range) age, weight, and serum creatinine of the study population was 68 (40-82) years, 62 (40-82) kg, and 1.4 (0.6-6.4) mg/dL, respectively. The pharmacokinetics of ampicillin and sulbactam were best described by a two-compartment model with serum creatinine most closely associated with clearance for both drugs. The estimated ampicillin and sulbactam clearances were 5.58 L/h and 4.79 L/h, respectively, while the volumes of distribution were 12.6 L and 15.36 L, respectively. Approved dosing regimens of ampicillin-sulbactam were sufficient against MICs ≤ 8 and ≤ 4 mg/L, respectively. A 4-h infusion enabled optimal PTA at higher MICs. For both dosing targets, optimal FTAs were obtained against Streptococcus pneumoniae.

CONCLUSION

Optimal FTAs were obtained against the susceptible MIC distributions of Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii. Applying a 4-h infusion will enhance PTA and FTA, particularly at higher MICs.

No Resistance to Penicillin, Cefuroxime, Cefotaxime, or Vancomycin in Pneumococcal Pneumonia

OBJECTIVES

Group B Streptococcus is a primary source of pneumonia, which is a leading cause of death worldwide. During the last few decades, there has been news of growing antibiotic resistance in group B streptococci to penicillin and different antibiotic agents. This clinical study retrospectively analyzes antimicrobial resistance in inpatients who were diagnosed with group B streptococcal pneumonia.

METHODS

All of the required information from inpatients who were identified to have group B streptococcal pneumonia was sourced from the database at the Department of Internal Medicine of HELIOS Clinic Wuppertal, Witten/Herdecke University, in Germany, from 2004-2014. Antimicrobial susceptibility testing was performed for the different antimicrobial agents that were regularly administered to these inpatients.

RESULTS

Sixty-six inpatients with a mean age of 63.3 ± 16.1 years (45 males [68.2%, 95% CI 60.0%-79.4%] and 21 females [31.8%, 95% CI 20.6%-43.0%]) were detected to have group B streptococcal pneumonia within the study period from January 1, 2004, to August 12, 2014. Group B Streptococcus had a high resistance rate to gentamicin (12.1%), erythromycin (12.1%), clindamycin (9.1%), and co-trimoxazole (3.0%), but it was not resistant to penicillin, cefuroxime, cefotaxime, or vancomycin (P < 0.0001).

CONCLUSION

No resistance to penicillin, cefuroxime, cefotaxime, or vancomycin was detected among inpatients with pneumonia caused by group B streptococci.

No development of ciprofloxacin resistance in the Haemophilus species associated with pneumonia over a 10-year study

Background

The widespread overuse of antibiotics promotes the development of antibiotic resistance in bacteria, which can cause severe illness and constitutes a major public health concern. Haemophilus species are a common cause of community- and nosocomial-acquired pneumonia. The antibiotic resistance of these Gram-negative bacteria can be prevented through the reduction of unnecessary antibiotic prescriptions, the correct use of antibiotics, and good hygiene and infection control. This article examines, retrospectively, antibiotic resistance in patients with community- and nosocomial-acquired pneumonia caused by Haemophilus species.

Methods

The demographic, clinical, and laboratory data of all patients with community- and nosocomial-acquired pneumonia caused by Haemophilus species were collected from the hospital charts at the HELIOS Clinic, Witten/Herdecke University, Wuppertal, Germany, within a study period from 2004 to 2014. Antimicrobial susceptibility testing was performed for the different antibiotics that have been consistently used in the treatment of patients with pneumonia caused by Haemophilus species.

Results

During the study period of January 1, 2004, to August 12, 2014, 82 patients were identified with community- and nosocomial-acquired pneumonia affected by Haemophilus species. These patients had a mean age of 63.8 ± 15.5 (60 [73.2 %, 95 % CI 63.6 %–82.8 %] males and 22 [26.8 %, 95 % CI 17.2 %–36.4 %] females). Haemophilus species had a high resistance rate to erythromycin (38.3 %), ampicillin (24.4 %), piperacillin (20.8 %), cefuroxime (8.5 %), ampicillin-sulbactam (7.3 %), piperacillin-sulbactam (4.3 %), piperacillin-tazobactam (2.5 %), cefotaxime (2.5 %), and levofloxacin (1.6 %). In contrast, they were not resistant to ciprofloxacin in patients with pneumonia (P = 0.016).

Conclusion

Haemophilus species were resistant to many of the typically used antibiotics. Resistance toward ciprofloxacin was not detected in patients with pneumonia caused by Haemophilus species.

Ampicillin-sulbactam: an update on the use of parenteral and oral forms in bacterial infections

Ampicillin-sulbactam has a wide range of antibacterial activity that includes Gram-positive and Gram-negative aerobic and anaerobic bacteria. However, the drug is not active against Pseudomonas aeruginosa and pathogens producing extended-spectrum beta-lactamases. The combination could be considered particularly active against Acinetobacter baumannii infections due to the intrinsic activity of sulbactam. The drug is indicated as empirical therapy for a broad range of community acquired infections supervened in adults or children and is effective in either parenteral (ampicillin-sulbactam) or oral (as a mutual prodrug sultamicillin) form. In clinical trials, sultamicillin has proved clinically and bacteriologically effective in adults and children against a variety of frequently encountered infections, including mild upper and lower respiratory tract infections, urinary tract infections, diabetic foot and skin and soft tissue infections. Furthermore, adverse effects rarely occur with the diarrhoea to represent the most commonly reported. The parenteral ampicillin-sulbactam is indicated for community infections of mild-to-moderate severity acquired infections such as intra-abdominal or gynecological. Moreover, it seems to represent the alternative of choice for the treatment of A. baumannii infections for carbapenem-resistant strains in the nosocomial setting. Thus, ampicillin-sulbactam remains a valuable agent in the physician's armamentarium in the management of adult and pediatric infections.

Effectiveness of cephalosporins in the sputum of patients with nosocomial bronchopneumonia

Nosocomial bronchopneumonia is a frequent complication in patients with chronic intratracheal intubation. Despite targeted antibiotic treatment, production of abundant bronchial secretion containing pathogen bacteria often tends to be chronic, and so mortality drastically increases. This problem led to an investigation of the penetration of five cephalosporin antibiotics into the sputum. Serum and sputum were collected from 24 chronically intubated patients having purulent nosocomial bronchopneumonia treated in an intensive care unit (ICU). Patients received the following doses intravenously every 24 h: five received 70 mg/kg of body weight cefuroxime, four received 110 mg/kg cefamandole, six received 80 mg/kg ceftriaxone, four received 80 mg/kg ceftazidime, and five received 80 mg/kg cefepime. Antibiotic concentrations in the serum and sputum were evaluated by capillary electrophoresis. MICs were determined for bacteria isolated from the purulent bronchial secretions. The mean levels of the cephalosporins in the sputum did not reach the MICs for the bacteria isolated from the same samples. Ceftriaxone was the only one of the investigated five cephalosporins that had a measurable concentration in the sputum (1.4 +/- 1.2 mg/liter). The low concentration of antibiotics in the purulent tracheobronchial secretion can be one of the many reasons for ineffective therapy of nosocomial bronchopneumonia in intubated patients in the ICUs. In the case of intubated or mechanically ventilated patients having chronic bronchopneumonia, determination of drug concentration in the bronchial secretion might be considered when selecting an antibiotic for treatment.

Penicillins for Treatment of Pneumococcal Pneumonia: Does In Vitro Resistance Really Matter?

BACKGROUND

The rate of in vitro bacterial resistance to antimicrobial agents is escalating among pathogens that cause the most serious respiratory tract infections. Many reports published during the past few years suggest that this has direct clinical implications. In particular, resistance of Streptococcus pneumoniae to beta-lactam antibiotic therapy has assumed a prominent role in the evolution of guidelines for the initial treatment of respiratory tract infection.

METHODS

I conducted a critical review of the published medical literature.

RESULTS

There is only a single report of documented microbiologic failure of parenteral penicillin-class antibiotics in the treatment of pneumococcal pneumonia in patients with or without bacteremia, whereas there are numerous well-documented reports of treatment failure with quinolone-class (n > or = 21) and macrolide-class (n > or = 33) antibiotics in the treatment of pneumococcal pneumonia.

CONCLUSION

The recommended optimal in-hospital therapy for community-acquired pneumonia should continue to be a beta-lactam antibiotic (penicillin, aminopenicillin, cefotaxime, or ceftriaxone) administered with a macrolide or a fluoroquinolone agent for adjunctive treatment of infection with potential atypical pathogens.

Role of beta-lactam agents in the treatment of community-acquired pneumonia

Community-acquired pneumonia (CAP) is a common illness associated with high rates of morbidity and mortality worldwide. The beta-lactam antibacterial agents have been the mainstay of therapy for CAP for over four decades and remain as first-line therapy. However, the impact of the substantial prevalence of resistance seen among the common respiratory pathogens, particularly penicillin and macrolide resistance among Streptococcus pneumoniae, is now an area for concern. CAP treatment guidelines often recommend the use of a macrolide or fluoroquinolone in conjunction with, or as an alternative to, beta-lactam agents, but whether this is necessary is uncertain. This review outlines the historical use of beta-lactam antibacterial agents in the treatment of CAP along with their ongoing therapeutic utility.

Role of sultamicillin and ampicillin/sulbactam in the treatment of upper and lower bacterial respiratory tract infections

The emergence of beta-lactamase-mediated resistance to beta-lactam antibiotics among key respiratory tract pathogens has threatened the usefulness of the beta-lactam agents familiar to physicians as being clinically effective and well tolerated. This article reassesses the clinical usefulness of ampicillin when administered in combination with the beta-lactamase inhibitor sulbactam, either intravenously or orally (as the mutual prodrug sultamicillin), in the treatment of upper and lower respiratory tract infections. Numerous clinical studies and several meta-analyses indicate that ampicillin/sulbactam and sultamicillin are clinically effective and well tolerated in both adults and children, in agreement with published North American and European guidelines.

Evidence-based medicine: empiric antibiotic therapy in community-acquired pneumonia

A number of national society guidelines exist for empiric management of community-acquired pneumonia but these are, to a large extent, not evidence-based, but based on clinical experience, in vitro data, pragmatism and common sense. Many randomized controlled trials of antibiotic therapy in community-acquired pneumonia have been conducted, but most of these have been powered to demonstrate equivalent efficacy of new treatments in comparison with conventional antimicrobial therapy. Development of new antibiotics has been driven by the emergence of penicillin-resistant Streptococcus pneumoniae, but so far there is no hard evidence that beta-lactam therapy fails in community-acquired pneumonia, at least with the higher doses of penicillins that are commonly used in hospital practice. Nonetheless, newer antibiotics have been deployed including macrolides and quinolones, and have demonstrated equivalent (and in some cases, marginally improved) efficacy to older antibiotic treatments in randomized control trials. A number of studies have shown that it is possible to stratify patients according to severity of illness, to in-patient or out-patient management protocols. These have been validated and refined.

Severe pneumonia. When and why to hospitalize

Relatively simple objective criteria are now available to predict which patients are at risk for bad outcomes from community-acquired pneumonia. In general, these include older patients and those with certain coexisting illnesses (especially neoplastic disease) or findings of altered mental status, hypotension, severe tachycardia, tachypnea, fever, acidemia, azotemia, hypoxemia, hyperglycemia, anemia, or hyponatremia. The major causes of severe pneumonia are S pneumoniae, H influenzae, and L pneumophila. Less common causes include mixed aerobic and anaerobic mouth flora, as well as M pneumoniae, C pneumoniae, gram-negative bacilli, and S aureus. Specific diagnosis is hampered by a lack of reliable diagnostic tests, but Gram's stain of expectorated sputum and cultures of sputum and blood may occasionally be helpful. Many empirical treatment regimens have been recommended, including those of the American Thoracic Society and the Infectious Diseases Society of America, which are reviewed here. It is hoped that better diagnostic tools will permit future targeting of microbes with narrow-spectrum therapy to diminish the risk of selection of resistant strains with empirical regimens.

Comparison of cefdinir and cefaclor in treatment of community-acquired pneumonia

Six hundred ninety patients were enrolled in a multicenter, randomized, double-blind trial comparing the efficacy and safety of cefdinir with those of cefaclor in the treatment of community-acquired pneumonia. Patients received either 10 days of treatment with cefdinir (n = 347) at 300 mg twice daily or 10 days of treatment with cefaclor (n = 343) at 500 mg three times daily. Microbiological assessments were performed on sputum specimens obtained at admission and at the two posttherapy visits, if available. Respiratory tract pathogens were isolated from 538 (78%) of 690 patient admission sputum specimens, with the predominant pathogens being Haemophilus parainfluenzae, Haemophilus influenzae, Streptococcus pneumoniae, and Staphylococcus aureus. The microbiological eradication rates at the test-of-cure visit were 92% (238 of 260 pathogens) and 93% (245 of 264 pathogens) for the evaluable patients treated with cefdinir and cefaclor, respectively. A satisfactory clinical response (cure plus improvement) was achieved in 89% (166 of 187) and 86% (160 of 186) of the evaluable patients treated with cefdinir and cefaclor, respectively. Except for the incidence of diarrhea, adverse event rates while on treatment were equivalent between the two treatment groups. Diarrhea incidence during therapy was higher for patients treated with cefdinir (13.7%) than for patients treated with cefaclor (5.3%). These results indicate that cefdinir is effective and safe in the treatment of patients with pneumonia.