Comparison of the effects of single doses of the new H1-receptor antagonists loratadine and terfenadine versus placebo in children

Johnston²,

Pediatric Allergy Immunology

2000

Self Cite

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.

Section: Discussionmentioning

confidence: 88%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

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

Johnston²,

Pediatric Allergy Immunology

2000

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“…It selectively binds to H 1 peripheral receptors and penetrates poorly into the CNS. It has a lower affinity for CNS H 1 receptors, as well as for serotonin, cholinergic, and α‐adrenergic receptors (22). There is little published information on the pharmacokinetics of loratadine in children.…”

Section: Second‐ and Third‐generation H1rasmentioning

confidence: 99%

Use and safety of antihistamines in children

Chae

Tharp

2000

Dermatologic Therapy

Although first‐generation antihistamines remain popular for the treatment of seasonal allergic rhinitis, atopic dermatitis, and urticaria in children, second‐ and third‐generation antihistamines hold clear advantages over the first‐generation agents, especially for the pediatric patient. The less frequent dosing schedule of the second‐ and third‐generation agents makes administration easier for the parent. With less sedation and lower risk of adverse effects, the safety profile of second‐ and third‐generation agents appears superior to that of first‐generation agents. After briefly discussing the use of first‐generation antihistamines, the pharmacokinetics, safety, and use of the newer antihistamines loratadine, cetirizine, and fexofenadine in the pediatric patient are reviewed.

“…The wheal and flare circumferences were traced with a pen at 10 min and transferred to paper with transparent tape. Wheal and flare areas were measured by a computerized digitizing system (10).…”

Section: Technique Of Skin Testingmentioning

confidence: 99%

Adverse central nervous system effects of older antihistamines in children

Pediatric Allergy Immunology

Fraser

Reggin

et al. 1996

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Although older, potentially sedating, "first-generation" antihistamines (H1-receptor antagonists) are commonly used in childhood, their central nervous system (CNS) effects have not been well-documented in young subjects. We hypothesized that diphenhydramine and hydroxyzine would affect CNS function adversely in this population. Our objective was to evaluate the effects of these medications on central and peripheral histamine H1-receptors in children. Fifteen subjects with allergic rhinitis were tested before and 2-2.5 h after administration of diphenhydramine, hydroxyzine, or placebo in a double-blind, single-dose, three-way crossover study. Impairment of cognitive processing was assessed objectively by the latency of the P300 event-related potential (P300). Somnolence was assessed subjectively by a visual analog scale. Peripheral H1-blockade was assessed by suppression of the histamine-induced wheals and flares. At the central (Cz) and frontal (Fz) electrodes, diphenhydramine and hydroxyzine increased the P300 latency significantly (P < 0.05) compared to baseline. Hydroxyzine increased somnolence, as recorded on the visual analog scale, significantly compared to baseline (P < 0.05), with a similar trend for diphenhydramine (P = 0.07). Both antihistamines reduced histamine-induced wheals and flares significantly compared to baseline and compared to placebo. In children, diphenhydramine and hydroxyzine are effective H1-receptor antagonists, but both these medications cause CNS dysfunction, as evidenced by increased P300 latency, a measure of cognitive function, and by increased subjective somnolence.