Cetirizine per os: exposure and antihistamine effect in the dog

Abstract

BackgroundCetirizine is an antihistamine used in dogs, but plasma concentrations in relation to effect after oral administration are not well studied. This study investigated cetirizine exposure and the plasma cetirizine concentration-antihistamine response relation in the dog following oral administration of cetirizine.ResultsEight Beagle dogs were included in a cross-over study consisting of two treatments. In treatment one, cetirizine 2–4 mg/kg was administered per os once daily for 3 days. The other treatment served as a control. Wheal diameter induced by intra-dermal histamine injections served as response-biomarker. Cetirizine plasma concentration was quantified by UHPLC-MS/MS. Median (range) cetirizine plasma terminal half-life was 10 h (7.9–16.5). Cetirizine significantly inhibited wheal formation compared with the premedication baseline. Maximum inhibition of wheal formation after treatment with cetirizine per os was 100% compared with premedication wheal diameter. The median (range) IC50-value for reduction in wheal area was 0.33 µg/mL (0.07–0.45). The median (range) value for the sigmoidicity factor was 1.8 (0.8–3.5). A behavioral study was also conducted and revealed no adverse effects, such as sedation.ConclusionThe results indicate that a once-daily dosing regimen of 2–4 mg/kg cetirizine per os clearly provides a sufficient antihistamine effect. Based on this experimental protocol, cetirizine may be an option to treat histamine-mediated inflammation in the dog based on this experimental protocol but additional clinical studies are required.

Transcriptomes from German shepherd dogs reveal differences in immune activity between atopic dermatitis affected and control skin

“…Treatment protocols included methylprednisolone used in the dose range of 0.2-0.35 mg/kg every other day, and it is well known that corticosteroids have immunosuppressive properties (Bonagura 1995). Moreover, cetirizine was used in the dose 1 mg/kg BID and antihistamine blocks histamine receptors and stabilizes mast cells (Ekstrand et al 2018). The overall gene expression profiles provided from this study showed that cases had a lower within-group variation compared to controls, which may be explained by the similar disease state in cases (i.e., CAD cases were under similar treatment protocols).…”