Clinical pharmacology of the H₁‐receptor antagonists cetirizine and loratadine in children

Abstract

H1-receptor antagonists are widely used in children but are not as well-studied in children as they are in adults. Our objective was to determine the onset and duration of action and the relative potency of the H1-receptor antagonists cetirizine and loratadine in children. We performed a prospective, randomized, placebo-controlled, double-blind, crossover, single-dose study of cetirizine and loratadine using suppression of the histamine-induced wheal and flare as the primary outcome. In 15 allergic children, mean age 9 years, compared with baseline, cetirizine (10 mg) suppressed the wheals and flares significantly from 0.25 to 24 h, achieving nearly 100% of flare suppression from 2 to 24 h, inclusive, and loratadine (10 mg) suppressed the wheals and flares significantly from 0.75 to 24 h, inclusive. Cetirizine suppressed the wheals and flares significantly more than loratadine from 0.25 to 1 h, inclusive, and at 0.5, 1, 2, 3, 5, 6, 7, and 24 h, respectively. Placebo also suppressed the wheal and flare significantly at some assessment times. Cetirizine and loratadine both have excellent antihistaminic activity in children, with a rapid onset of action and a 24-h duration of action in this population.

Central Nervous System Side Effects of First- and Second-Generation Antihistamines in School Children With Perennial Allergic Rhinitis: A Randomized, Double-Blind, Placebo-Controlled Comparative Study

“…We did not measure histamine-induced wheal and flare to evaluate blockade of peripheral H1 receptors by the treatment. However, various studies have shown that both cetirizine 10 mg 35,36 and chlorpheniramine 4 mg 24,37 are effective in suppressing histamine-induced wheal and flare in children. Another potential confounding factor was the different pharmacokinetics of both drugs.…”

Levocetirizine: Pharmacokinetics and pharmacodynamics in children age 6 to 11 years

“…3 Most of the orally administered H 1 -antihistamines are available in dosage formulations suitable for administration to children and even to infants; however, only 11 of the 40 H 1 -antihistamines have been studied prospectively in children with regard to their pharmacokinetics and pharmacodynamics. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] These studies have generally been conducted after administration of a single dose, 5-10,12-20 but 3 studies have been performed at steady state, 11,12,20 and in a few studies, a population pharmacokinetic design [21][22][23] has been used. The clinical pharmacology of a few of the first-generation H 1 -antihistamines, such as chlorpheniramine, brompheniramine, diphenhydramine, and hydroxyzine, was investigated after they had been used in children for several decades.…”

Clinical and Pharmacological Peculiarities of Cetirizine Use for the Therapy of Allergic Diseases in Children

“…Antihistamine effect of cetirizine develops rapidly. A single dose of 10 mg of the medication inhibits the histamine-induced blistering-hyperemic skin reaction as effectively as loratadine and more effectively than fexofenadine in therapeutic doses [9,10]. The antihistamine action of cetirizine is demonstrated in other tissues involved in allergic reactions as well.…”