Biomedical subjects
H Bhend
Publications and source records attributed to H Bhend.
Increase of amikacin half-life during therapy in patients with renal insufficiency.
Serum kinetics of amikacin were investigated in 17 severely ill patients. During both the first and last dose intervals of therapy, the serum concentration time course of every patient was documented by 17 blood samples. Six of the patients had moderate to severe renal insufficiency (serum creatinine greater than 1.5 mg/100 ml). In this group of patients, a pronounced rise in serum half-life of amikacin was observed, increasing from a mean of 11.2 to 21.5 h for the first and last interval, respectively. In contrast, mean half-life remained stable in the group of 11 patients with normal renal function. No change in mean serum creatinine occurred in either group, when data from the beginning and the end of therapy were compared. Therefore, the increase of amikacin half-life is apparently not due to a reduction of the glomerular filtration rate, but rather to a decrease of the ratio of amikacin to creatinine clearance. Indeed, a significant reduction of this ratio could be shown in the seven patients in which 24-h creatinine clearance was determined during the first and last day of therapy. This phenomenon is discussed in the context of aminoglycoside accumulation in deep compartments. We conclude that the daily dose of amikacin has to be reduced during therapy in patients with impaired, but stable, renal function.
[Incidence of bacteremia in heart catheterization: results of a prospective study on the prevention of endocarditis with cefazoline versus placebo].
145 consecutive patients scheduled for a cardiac catheterization were enrolled in a prospective double-blind randomized study to determine the incidence of bacteremia during and following catheterization and the usefulness of antibiotic prophylaxis with cefazolin versus placebo during this procedure. Four blood cultures were taken from each patient to evaluate the incidence of bacteremia vs. contamination. 15 of 296 (5.07%) and 11 of 284 (3.8%) cultures yielded bacteria in the placebo group (74 patients) and in the cefazolin-group (71 patients) respectively. Statistical analysis revealed no significant difference between the groups. These results, together with the spectrum of the organisms isolated and the clinical and laboratory findings, suggest that the isolation of bacteria was due rather to contamination than the result of bacteremia. It is concluded that antibiotic prophylaxis in patients undergoing cardiac catheterization is unnecessary and not indicated.
Human pharmacology of cefotaxime (HR 756), a new cephalosporin.
Cefotaxime (HR 756) is a new semisynthetic parenteral cephalosporin with exceptional activity against gram-negative organisms and considerable stability against their beta-lactamases. To study its pharmacokinetic properties, 0.5-, 1-, and 2-g doses were administered to each of six volunteers intravenously over 15 min, followed by a sustaining infusions of 0.5, 1, and 2 g/h, respectively, for 3 consecutive hours. The loading doses produced mean peak levels of 41, 93, and 160 mug/ml, and mean steady-state serum concentrations were 27, 64, and 138 mug/ml, respectively. The mean terminal half-life was 75 +/- 7 min. The total volume of distribution averaged 0.22 +/- 0.03 liters/kg of body weight. Total body and renal clearances were 232 +/- 30 and 145 +/- 24 ml/min per 1.73 m(2), respectively; 63 +/- 9% of the administered dose was excreted through the kidneys in 24 h. To determine the effect of cefotaxime on the renal tubules, urinary alanine aminopeptidase excretion was measured before, during, and after the infusions. It remained within the normal range in all instances; however, 48 +/- 14% of the total daily alanine aminopeptidase output was recovered during the infusion period. Side effects were dose related and included fatigue, loose stools, and night sweats. No significant changes in hematology, serum chemistry, or urinalysis were recorded.
[On-line measurement of antibiotic concentrations (author's transl)].
A laboratory computer implementation of an inhibition zone antibiotic assay is described. It utilizes square plates with 49 or 64 wells containing standards and unknowns. Inhibition zone sizes are measured and, using parabolic regression, the unknown antibiotic concentrations are computed.