Efficacy of increased dose of rupatadine up to 20 mg on itching in Japanese patients due to chronic spontaneous urticaria, dermatitis, or pruritus: A post hoc analysis of phase III clinical trial

Abstract

Objectives The effect of rupatadine, a novel H1 antihistamine with platelet‐activating factor antagonist activity, had been demonstrated for itching in Japanese patients with chronic spontaneous urticaria, dermatitis, or pruritus in a 12‐month, open‐label clinical trial (JapicCTI‐152787). However, patients could have received an updose at various timings due to distinct reasons in the study; timing of updose was not evaluated. This study aimed to elucidate the relationship between performance of rupatadine and timing of updose. Methods For 206 enrolled patients was evaluated the total pruritus score (TPS) to Week 2 with 10 mg rupatadine. From Week 3 to Week 52, rupatadine was updosed to 20 mg accordingly. Subpopulation was categorized by absence/presence of updosing and timing of updose (Week 3 or ≥Week 5). Results Reduction of TPS from baseline to Week 2 in patients updosed at Week 3 was significantly lower than those given an updose at ≥Week 5 and fixed dose. However, significant improvement in the change in mean TPS from 1 week pre‐updose to the second week post‐updose was achieved regardless of updose timing, scoring −0.903 for Week 3 and −0.983 for ≥Week 5 (P < 0.001). Conclusions The results inferred the inclusivity of patients who either updosed during the earlier phase due to lack of efficacy, or later due to aggravation of symptoms. The results of this subgroup analysis produced evidence of appropriateness for using 10 mg rupatadine as the starting dose, and evaluating the necessity of updose to 20 mg during the first 2 weeks for nonresponsive patients.

A single reaction-diffusion equation for the multifarious eruptions of urticaria

“…Moreover, the efficacy of antihistamines in urticaria is extremely variable, and not necessarily determined by the clinical severity of urticaria. [3,19]. Therefore, morphological analysis of such eruptions of urticaria may reveal the mechanism of action of histamine in more detail, especially with respect to its diffusion with kinetics, and offer a clue for more personalized treatment.…”