Characterization of anti-inflammatory properties and evidence for no sedation liability for the novel antihistamine SUN-1334H.

BACKGROUND: The anti-inflammatory potential of antihistamines has significant clinical utility. Long-term pharmacotherapy of so-called 'safe' antihistamines may be hampered by side effects in the central nervous system. In the present study, the new potential antihistamine SUN-1334H was compared with different antihistamines for anti-inflammatory effects, sedation potential and interaction with alcohol. METHOD: Nasal and skin allergy were induced in guinea pig and mice by ovalbumin sensitization and challenge. Neurogenic nasal inflammation was induced by capsaicin. Sedation potential and interaction with alcohol were assessed by i.v. and intracerebroventricular pentobarbital-induced sedation and alcohol-induced ataxia models. RESULTS: Ovalbumin sensitization and challenge caused rhinitis pathology including inflammatory cell infiltration, IL-4, and protein leakage in the nasal lavage fluid (NLF) and presence of inflammatory cells in nasal epithelium. A 5-day treatment of antihistamines reduced these markers of inflammation. SUN-1334H, cetirizine and hydroxyzine caused comparable inhibition of NLF leukocytes, IL-4 and total protein concentrations. Fexofenadine and desloratadine showed moderate inhibition of NLF leukocytes and had no significant effect on IL-4 concentration. While fexofenadine had no effect on total protein concentration, the effect of desloratadine was comparable with the other antihistamines. In neurogenic nasal inflammation induced by capsaicin, SUN-1334H and fexofenadine caused better inhibition at lower and middle dose levels than the other antihistamines. In skin allergy models, SUN-1334H showed potent reduction of passive and active cutaneous anaphylactic reactions. In central nervous system side effects models, SUN-1334H, desloratadine and fexofenadine were devoid of any significant effects. CONCLUSIONS: The results are suggestive of a high anti-inflammatory to sedation index of SUN-1334H among leading antihistamines.

Turbidimetric carbamazepine immunoassay on the ADVIA 1650 and 2400 analyzers is free from interference of antihistamine drugs hydroxyzine and cetirizine.

A recent report indicates that hydroxyzine and its active metabolite cetirizine interfere with the particle-enhanced turbidimetric inhibition immunoassay (PENTINA) carbamazepine assay. We studied potential interference of hydroxyzine and cetirizine with the turbidimetric carbamazepine immunoassay on ADVIA 1650 and ADVIA 2400 (Bayer Diagnostics, Tarrytown, NY) analyzers. Aliquots of drug-free serum pools were supplemented with various concentrations of hydroxyzine and cetirizine representing therapeutic, moderate toxic, as well as very toxic concentrations. These samples were assayed by the turbidimetric carbamazepine immunoassay on two analyzers. To study the interference in presence of the analyte, aliquots of a serum pool prepared from patients receiving carbamazepine were further supplemented with various amounts of hydroxyzine and or cetirizine and apparent carbamazepine concentrations were measured again in order to compare with the value of original pool. No apparent carbamazepine concentration was observed when aliquots of drug-free serum were supplemented with hydroxyzine or cetirizine. Moreover, in the carbamazepine pool, the original carbamazepine concentration compared well when aliquots of this serum pool were further supplemented with hydroxyzine or cetirizine. We conclude that the turbidimetric carbamazepine immunoassay is free from interference of hydroxyzine and cetirizine.

[A case of drug allergy to hydroxyzine used for premedication].

A 37-year-old woman, scheduled for total knee replacement, complained of nausea and abdominal pain 30 min after pre-medication with intramuscular atropine and hydroxyzine. Hypoxemia and skin eruption all over her body was noticed in the operating room. Although hemodynamic changes were not observed, the operation was postponed. LST (lymphocyte stimulation test) showed the positive response with hydroxyzine but negative with atropine and antibiotics. This result suggests that hypersensitivity was caused by hydroxyzine in this patient.

Does reversed-type anaphylaxis in healthy subjects mimic a real allergic reaction?

Immediate and late cutaneous reactions were induced in healthy and atopic subjects by anti-IgE challenge and a skin-window technique was used in order to verify if the pattern of cells observed at 24 hr was similar in both groups. The study was first performed under basal conditions, and in a second double-blind cross-over step, it was performed again during treatment with cetirizine 10 mg b.i.d. and terfenadine 60 mg b.i.d. Anti-IgE challenge was followed by a significant eosinophil accumulation in atopic subjects only. Cetirizine significantly inhibited this phenomenon while terfenadine showed a mild non-significant inhibitory effect.