A total of 22 asymptomatic patients with a documented history of
allergic rhinitis participated in this single-centre, double-blind, randomized, placebo-controlled, cross-over trial undertaken to assess the efficacy and tolerability of
levocabastine nasal spray (0.5 mg/ml) in the prevention of
allergen-induced nasal symptoms. Objective assessment of nasal symptoms revealed that the severity of
sneezing was significantly lower following treatment with
levocabastine (p < 0.001), with rhinorrhoea also tending to be less severe in the
levocabastine-treated group (0.05 < p < 0.1). Rhinomanometry and acoustic rhinometry failed to reveal any significant intergroup differences, and there were no differences in nasal
albumin concentrations between the two treatment groups. Patients' VAS ratings revealed significant differences in favour of
levocabastine for
sneezing (p < 0.001) and
itching (p < 0.05), with the severity of rhinorrhoea also tending to be lower during treatment with this topical
antihistamine (0.05 < p < 0.1). The mean total symptom score was also significantly lower in
levocabastine-treated patients (p < 0.05).
Levocabastine was well tolerated. Only two adverse events were reported:
fatigue in one patient, and vesicular
rash with facial oedema and
urticaria in another. In conclusion, intranasal
levocabastine provided effective protection from nasal
allergen challenge and would appear to be a valuable therapeutic approach in patients with
allergic rhinitis.