Pharmacokinetics of famotidine in infants

Clin Pharmacokinet. 2005;44(4):395-406. doi: 10.2165/00003088-200544040-00004.


Background: Although famotidine pharmacokinetics are similar in adults and children older than 1 year of age, they differ in neonates owing to developmental immaturity in renal function. Little is currently known about the pharmacokinetics of famotidine in infants aged between 1 month and 1 year, a period when renal function is maturing.

Objective: To characterise the pharmacokinetics of famotidine in infants.

Design: This was a two-part multicentre study with both single dose (Part I, open-label) and multiple dose (Part II, randomised) arms.

Patients: Thirty-six infants (20 females and 16 males) who required treatment with famotidine and who had an indwelling arterial or venous catheter for reasons unrelated to the study.

Methods: Infants in Part I were administered a single dose of famotidine 0.5 mg/kg; the dose was intravenous or oral according to the judgement of the attending physician. Infants receiving 0.5 mg/kg intravenously were divided into two groups by age, and pharmacokinetic parameters in infants 0-3 months and >3 to 12 months of age were compared. Infants in Part II were randomised to one of the following treatments: 0.25 mg/kg/dose intravenously or 0.5 mg/kg/dose orally on day 1 and subsequent days, or 0.25 mg/kg/dose intravenously or 0.5 mg/kg/dose orally on day 1 followed by doses of either 0.5 mg/kg/dose intravenously or 1 mg/kg/dose orally on subsequent days. From day 2 onwards, age-adjusted dose administration regimens (once daily in infants <3 months of age and every 12 hours in infants >3 months of age) were used; the total number of famotidine doses ranged from 3 to 11 and the total number of days of dose administration ranged from two to eight.

Results: In infants <3 months of age, plasma and renal clearance of famotidine were decreased compared with infants >3 months of age. Pharmacokinetic parameters for the older infants (i.e. those >3 months) were similar to those previously reported for children and adults. Approximate dose-proportionality, no accumulation on multiple dosing and an estimated bioavailability similar to adult values were also observed.

Conclusion: A short course of famotidine therapy in infants appears generally well tolerated, and the characteristics of famotidine pharmacokinetics during the first year of life are explained to a great degree by the development of renal function, the primary route of elimination for this drug.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Area Under Curve
  • Biological Availability
  • Famotidine / blood
  • Famotidine / pharmacokinetics*
  • Famotidine / therapeutic use
  • Female
  • Gastroesophageal Reflux / drug therapy
  • Half-Life
  • Histamine H2 Antagonists / blood
  • Histamine H2 Antagonists / pharmacokinetics*
  • Histamine H2 Antagonists / therapeutic use
  • Humans
  • Infant
  • Infant, Newborn
  • Injections, Intravenous
  • Male
  • Metabolic Clearance Rate


  • Histamine H2 Antagonists
  • Famotidine