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A pharmacokinetic evaluation of the second‐generation H 1 ‐receptor antagonist cetirizine in very young children
Author(s) -
Desager J P,
Dab I,
Horsmans Y,
Harvengt C
Publication year - 1993
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1038/clpt.1993.47
Subject(s) - cetirizine , pharmacokinetics , medicine , pharmacodynamics , urine , antagonist , clinical pharmacology , pharmacology , receptor
The pharmacokinetics of the second‐generation H 1 ‐receptor antagonist cetirizine was studied in eight children younger than 4 years of age who were treated with a single dose of cetirizine solution (5 mg). These children were hospitalized with suspected allergic respiratory problems or recurrent respiratory tract infections. Blood samples were collected at ½, 1, 1½, 2, 4, 6, 8, 12, and 24 hours, and a 24‐hour urine collection was performed in five of the samples. The findings obtained in children were compared with those obtained in 16 healthy young adults (mean ± SD, 24.6 ±4.1 years) who received a single 20 mg dose. Cetirizine was absorbed more slowly in children (p = 0.006; mean ± SD, 1.44 ± 1.12 hours) than in adults (0.62 ± 0.22 hours). The plasma elimination half‐life of cetirizine was significantly shorter in children (p < 0.001; 4.91 ± 0.6 hours) than in adults (8.6 ± 2.1 hours), and the clearance rate was significantly higher in children (p < 0.001; 1.48 ± 0.41 ml/min/kg) than in adults (0.80 ± 0.17 ml/min/kg). Urinary excretion of unchanged cetirizine was significantly lower in children (p < 0.001; 37.8% ± 5.2%; n = 5) than in adults (57.7% ± 11.8%). Therefore the metabolism of cetirizine is faster in young children than in adults. This effect must be taken into account in future pharmacodynamic studies in this age group. Clinical Pharmacology and Therapeutics (1993) 53, 431–435; doi: 10.1038/clpt.1993.47