Influence of age and renal disease on aminoglycoside dosage

New guidelines for the administration of amikacin are presented for neonates, children and adults, with normal or impaired, stable or changing renal function. The dose is calculated according to the lean body mass, which can be estimated from weight, height and sex of the patient. The dosing interval is calculated from the predicted drug half-life, which is derived from creatinine clearance normalized to 50 kg lean body mass (LBM). A formula is presented to estimate directly the Ccr in ml/min per 50 kg LBM, based only upon serum creatinine concentrations and the age of the subject. Two electronic pocket calculators which contain the dosage guidelines of amikacin are also described. Les auteurs présentent de nouvelles recommandations pour la détermination de la posologie de l'amikacine chez les nouveau-nés, les enfants et les adultes dans le cas de fonction rénale normale ou altérée, de fuçon stable ou variable. La dose eat calculée selon la masse corporelle ‘dégraisséc' qui eat évaluée en fonction du poids, de la taille et du sexe du malade. L'intervalle entre les doses est calculé à partir de la demi-vie estimée selon la valeur de la clairance de la créatinine rapportée à 50 kg de masse corporelle ‘dégraissée'. Une formule eat donnée, qui permet de calculer directement la clairance de la créatinine en ml/min/50 kg de masse corporelle dégraissée basée uniquement sur la créatininémie et l'âgc du sujet. Deux calculateurs de poche programmées pour le calcul de la posologie de l'amikacine sont décrite

Circadian rhythm of urinary pH in man with and without chronic antacid administration

In normal human volunteers, when urinary pH was plotted versus time, the circadian sine-wave type curve was not altered by chronic administration of a commercially available suspension containing a mixture of magnesium and aluminum hydroxides, although the antacid perturbed the entire curve in a more alkaline direction. A single dose of the antacid had little effect on urinary pH. There was a highly significant linear relationship between the change in hydrogen ion concentration during chronic antacid treatment and the initial control urinary hydrogen ion concentration, but there was no significant correlation between change in urinary pH and initial control urinary pH as has been previously reported. The above results were based on the evaluation of the hydrogen ion concentrations of 1562 separate urine samples collected from 24 normal subjects in a three treatment crossover study. It is recommended that: (1) research studies involving drug-drug interactions with antacids be designed to consider the effect of the antacid on the circadian rhythm of urinary pH, and (2) pH values not be averaged as commonly reported in the literature, but rather the pH values be converted to hydrogen ion concentrations before statistical analysis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46636/1/228_2004_Article_BF00561060.pd