Pharmacokinetics and pharmacodynamics of famotidine in infants.
The pharmacokinetics and pharmacodynamics of intravenous famotidine were evaluated in 10 infants ranging from 5 to 19 days of age who had a therapeutic indication for the prophylactic treatment of stress ulceration. After a 0.5-mg/kg infusion of famotidine, timed serum (n = 6), urine (24-hour collection), and repeated measurements of gastric pH were obtained. The mean +/- standard deviation maximum plasma concentration (Cmax) was 640.66 +/- 250.66 ng/mL, the elimination half-life (t1/2 beta) was 10.51 +/- 5.43 hours, and the apparent volume of distribution at steady state (Vdss) was 0.82 +/- 0.29 L/kg. Plasma clearance (Cl) and renal clearance (ClR) were 0.132 +/- 0.061 L/hr/kg and 0.093 +/- 0.056 L/hr/kg, respectively. No significant correlations were found between t1/2 beta, Vdss, Cl, and ClR and age. Six of the nine infants who had intragastric pH monitoring maintained a gastric pH > 4 until the final 24-hour sampling point. In this study, the t1/2 beta of famotidine was prolonged and the Vdss, Cl, ClR were reduced compared with corresponding parameters in previously reported studies of children older than one year of age and adults.
James
L P
LP
University of Arkansas for Medical Sciences and Arkansas Children's Hospital, 800 Marshall Street, Little Rock, AR 72202, USA.
Marotti
T
T
Stowe
C D
CD
Farrar
H C
HC
Taylor
B J
BJ
Kearns
G L
GL
D015738:Famotidine / Q000493:pharmacokinetics* / Q000494:pharmacology; D005260:Female; D005745:Gastric Acidity Determination; D006635:Histamine H2 Antagonists / Q000493:pharmacokinetics*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008657:Metabolic Clearance Rate
D006635:Histamine H2 Antagonists; D015738:Famotidine