Pharmacokinetics and pharmacodynamics of cetirizine in infants and toddlers

Clin Pharmacol Ther. 1997 Mar;61(3):325-30. doi: 10.1016/S0009-9236(97)90165-X.

Abstract

The pharmacokinetics of the second generation H1-receptor antagonist cetirizine were studied in 15 infants and toddlers (mean +/- SD age, 12.3 +/- 5.4 months) who were treated with a single 0.25 mg/kg dose of cetirizine solution. The infants and toddlers were hospitalized for recurrent respiratory infections or other hypersensitivity-related diseases. Blood samples were collected at 1/2, 1, 11/2, 2, 4, 6, 8, 12, and 24 hours, and a 24-hour urine sample was obtained. A peak plasma level of 390 +/- 135 ng/ml was observed after 2.0 +/- 1.3 hours. The elimination half-life was 3.1 +/- 1.8 hours, the apparent oral body clearance was 2.13 +/- 1.15 ml/min/kg, and the apparent volume of distribution was 0.44 +/- 0.19 L/kg. The excretion of unchanged cetirizine in six complete urinary collections was 62.7% +/- 13.2% of the administered dose. An additional pharmacodynamic study (inhibition of the histamine-induced wheal and flare) was performed in 10 of these infants and toddlers, after the intake of 0.25 mg/kg cetirizine twice a day for at least 4 days. A 90% +/- 12% inhibition of the wheal and a 87% +/- 17% inhibition of the flare were still observed 12 hours after the last intake. The duration of the H1-inhibition by cetirizine at the cutaneous level is thus longer in infants and toddlers than could be inferred from its pharmacokinetics; the level of inhibition at 12 hours was the same as in older age groups.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Area Under Curve
  • Cetirizine / blood
  • Cetirizine / pharmacokinetics*
  • Cetirizine / pharmacology
  • Cetirizine / urine
  • Female
  • Histamine H1 Antagonists / blood
  • Histamine H1 Antagonists / pharmacokinetics*
  • Histamine H1 Antagonists / pharmacology
  • Histamine H1 Antagonists / urine
  • Humans
  • Hypersensitivity / blood
  • Hypersensitivity / metabolism*
  • Hypersensitivity / urine
  • Infant
  • Male
  • Time Factors

Substances

  • Histamine H1 Antagonists
  • Cetirizine