Ampicillin/sulbactam in elderly patients with community-acquired pneumonia.

PURPOSE: Age-related physiological changes affect body systems, altering pharmacokinetics, which may potentiate or alter the effects of drugs. The aim of this study was to assess the influence of age on the steady-state pharmacokinetics and pharmacokinetic/pharmacodynamic parameters of ampicillin/sulbactam in the population of elderly patients (age ≥65 years) with community-acquired pneumonia (CAP). PATIENTS AND METHODS: The pharmacokinetics and pharmacokinetic/pharmacodynamic parameters of ampicillin/sulbactam were determined at steady state in a total of 13 elderly patients with CAP following the administration of multiple intravenous doses of 2 g ampicillin + 1 g sulbactam (Unacid(®), Pfizer), each over 15 min thrice a day. RESULTS: A reduced C max, AUC0-8 h and total clearance, a prolonged half-life, and an increased steady-state volume of distribution were observed for ampicillin. The mean estimated free C min of 1.8 mg/L for ampicillin was higher than that predicted to be effective against Streptococcus pneumoniae. Based on an MIC90 of 1 mg/L for Streptococcus pneumoniae, the calculated T > MIC and T > 4 × MIC for ampicillin was 75-100 % (median 100 %) and 12.5-100 % (median 50 %), respectively. A T > 4 × MIC of at least 50 % was achieved in 7 of 13 elderly patients with CAP. CONCLUSIONS: Age and, probably, pneumonia did affect the pharmacokinetics of ampicillin and sulbactam. Despite the reduced C max, adequate free C min/MIC90 ratios due to impaired renal function were observed in elderly patients with CAP. In elderly patients without renal impairment and/or in severe infection with less susceptible pathogens, more frequent dosing of ampicillin 2 g/sulbactam 1 g can be necessary to avoid the risk of underdosing in CAP.

Pharmacokinetics and penetration of linezolid into inflamed soft tissue in diabetic foot infections.

OBJECTIVE: Physiological changes and local and systemic inflammation may affect plasma and tissue pharmacokinetics of antimicrobial agents in diabetics. The aim of the study was to investigate the penetration of linezolid into inflamed areas of infected diabetic foot wounds and the pharmacokinetics in the risk population of diabetics. METHODS: Pharmacokinetics and tissue penetration of linezolid into inflamed diabetic foot infection (DFI) tissue were determined at steady state in 15 patients with diabetes type 2 and DFI following administration of multiple oral doses of 600 mg given every 12 h. Second debridement was performed on days 4-6, 3 h after linezolid administration. Linezolid concentrations were determined in perinecrotic wound tissue of inflamed diabetic foot by high-performance liquid chromatography (HPLC). RESULTS: A mean maximum plasma concentration (C(max)) in plasma of 14.3 mg/L was attained at a median of 2.0 h [time to reach C(max) (T(max)) range 0.5-6.0 h). Area under the concentration time curve from zero to 12 h (AUC(0-12 h)) with a mean of 114.1 mgh/L and C(min) of 5.4 mg/L were achieved in patients with diabetes mellitus type 2. Penetration of linezolid into inflamed areas of DFI with tissue/plasma ratios of mean 101.7% [95% confidence interval (CI) 56; 148%] produced a mean concentration of 9.6 microg/g (95% CI 7.4; 11.8 microg/g) greater than those predicted to be effective against methicillin-resistant staphylococci [minimum concentration that inhibits 90% of organisms (MIC(90)) of 4 mg/L]. Tissue/plasma ratios correlated positive with systemic inflammation. CONCLUSION: Plasma pharmacokinetics of linezolid in diabetics and adequate levels in inflamed areas of diabetic foot wound suggest that an oral dose of 600 mg bd of linezolid provides effective concentrations for treating methicillin-resistant Staphylococcus aureus (MRSA) in DFI.

Improvement in central nervous system functions during treatment of liver failure with albumin dialysis MARS--a review of clinical, biochemical, and electrophysiological data.

The Molecular Adsorbent Recirculating System (MARS) is a nonbiological liver support method based on the principles of dialysis, filtration, and adsorption. It allows the safe and efficient removal of both albumin-bound and water-soluble toxic metabolites, including ammonia, aromatic amino acids, tryptophan, and related phenolic and indolic products, as well as benzodiazepines. A well-documented effect of the treatment is the improvement of the hemodynamic situation of decompensated chronic patients. Systemic vascular resistance, mean arterial pressure, cerebral blood flow, and cerebral oxygen consumption increased significantly. The degree of hepatic encephalopathy decreased significantly. Increased intracranial pressure could be normalized in both chronic and fulminant liver failure. In three randomized clinical trials significant improvement of survival could be demonstrated. In a model of murine neuronal networks cultured on multi-microelectrode array plates and incubated with plasma from liver failure patients, a normalization of the spike and burst pattern could be observed, if plasma samples from MARS-treated patients before and after treatment were compared. In conclusion, MARS significantly improves central nervous system functions. It can serve as a model for the further investigation of the role of protein-bound substances in hepatic encephalopathy and cerebral hemodynamics.

[Persistent Lactobacillus casei subspecies rhamnosus bacteremia in a 14 year old girl with acute myeloid leukemia. A case report]. / Persistierende Lactobacillus casei subspecies rhamnosus-Bakteriämie bei einer 14-jährigen Patientin mit akuter myeloischer Leukämie. Eine Kasuistik.

The present clinical observation is related to a 14-year-old girl suffering from acute myeloid leukemia. The clinical course was complicated by episodes of severe enterocolitis, E. coli- septicemia, pancreatitis and pneumonia. In the course of continued cytostatic and antibiotic treatment a persistent asymptomatic Lactobacillus casei subsp. rhamnosus-bacteremia became detectable by a total of 18 blood cultures. Microbial cultures of the faeces revealed colony-forming unites of this germ in orders of 10(9)/g. Antibiotic eradication attempts according to the resistogram were not successful. The Lactobacillus-bacteremia disappeared only after 13 months when the cytostatic therapy was terminated. An adjuvant influence of the Lactobacillus infection on the outcome of the underlying disease cannot be excluded.