A direct comparison of efficacy between desloratadine and rupatadine in seasonal allergic rhinoconjunctivitis: a randomized, double-blind, placebo-controlled study

How to handle off-label prescriptions of rupatadine, a second-generation antihistamine and PAF antagonist: a review

The off-label use of second-generation antihistamines, used outside of the formal indications authorized by regulatory authorities, in different age groups, doses or in special populations, is very common for many allergic, autoimmune and dermatological diseases. The off-label use of rupatadine (a second-generation antihistamine with PAF antagonist activity) in these conditions is reviewed here, including in combination with immunotherapy in the treatment of food allergy or allergic rhinitis, at high doses in chronic urticaria, and with prescriptions of less common but challenging conditions such as skin pruritus or mast cell activation disorders like mastocytosis. Rupatadine use is reviewed herein to confirm if its off-label management is supported by well-designed clinical trials or by published real-world cases. This review will contribute to increasing compliance and achieving better results in clinical practice. Off-label use of rupatadine should be left to the discretion of the prescribing healthcare professional after careful clinical evaluation.

Higher efficacy of rupatadine 20 mg and 10 mg versus placebo in patients with perennial allergic rhinitis: a pooled responder analysis

Background

The clinical efficacy of rupatadine in terms of responders has not been previously explored in perennial allergic rhinitis (PAR).

Methods

This pooled analysis included data from 6 randomised, double-blind, placebo-controlled trials conducted in PAR patients treated with rupatadine 10 mg or 20 mg, or placebo. Participants were aged ≥ 18 years, with diagnosis of PAR and a Total 4 Nasal Symptom Score (T4NSS) ≥ 5. We evaluated the T4NSS and Total 5 Symptom Score (T5SS) for 28 days of treatment, the responder proportion (50% and 75% response), and the time to response.

Results

Efficacy data from 1486 patients were analysed: 585 received placebo, 682 rupatadine 10 mg, and 219 rupatadine 20 mg. Compared with placebo, rupatadine promoted greater symptom improvements and higher responder proportions (50% and 75% response) for T4NSS and T5SS over 28 days. Symptom improvements and responder proportions were higher in the rupatadine 20 mg group vs the 10 mg group. The time to response was shorter in the rupatadine 20 mg group vs the 10 mg group for T4NSS (16 and 9 days for the 50% and 75% responses, respectively) and for T5SS (13 and 8 days for the 50% and 75% responses, respectively).

Conclusions

Rupatadine was efficacious in reducing allergic rhinitis symptoms, showing high responder proportions. The faster and stronger effect of rupatadine 20 mg may suggest its use in patients with severe PAR or not responding to the standard dose.

Clinically relevant effect of rupatadine 20 mg and 10 mg in seasonal allergic rhinitis: a pooled responder analysis

Background

Different clinical trials showed the superior efficacy of rupatadine compared to placebo at improving seasonal allergic rhinitis (SAR) symptoms, but no study has assessed if the response promoted is clinically meaningful.

Methods

This study is a pooled analysis of data of seven randomized, double-blind, placebo-controlled SAR studies comparing responder proportions upon treatment with rupatadine (10 or 20 mg) or placebo. We evaluated the following symptom scores at baseline (Visit 1) and over 14 days of treatment: Total 4 Nasal Symptom Score (T4NSS), Total 2 Ocular Symptom Score (T2OSS) and Total 6 Symptom Score (T6SS). The proportion of responders (50% and 75% response) and the time to response were compared between groups on days 7 (Visit 2) and 14 (Visit 3). Responder rates were compared between groups on days 7 and 14 for the complete/near-to-complete response for T4NSS (TN4SS score ≤ 2 and each symptom score ≤ 1) and T6SS (T6SS score ≤ 3 and each symptom score ≤ 1).

Results

Data from 1470 patients were analyzed: 332 treated with placebo, 662 with rupatadine 10 mg and 476 with rupatadine 20 mg. The reduction in T4NSS, T2OSS and T6SS over 14 days of treatment relative to baseline was statistically higher in rupatadine groups vs the placebo group, with greater improvements in the 20 mg group. A statistically higher proportion of patients reached the 50% and 75% response for T4NSS, T2OSS and T6SS in rupatadine groups compared to the placebo group across the visits. Among rupatadine-treated patients, those receiving 20 mg compared favourably for both cut-off responses. The time to achieve a proportion of responders was shorter in the rupatadine 20 mg group than in the rupatadine 10 mg and placebo groups for all the symptom scores. The number of patients who achieved a complete/near-to-complete response for both symptom scores was higher in rupatadine groups than in the placebo group, with higher proportions in the 20 mg group.

Conclusions

This responder analysis confirms the superior efficacy of rupatadine vs placebo to treat SAR. Rupatadine promoted higher proportions of responders according to stringent response criteria and in a dose-dependent manner, with faster and higher response rates in the 20 mg group.

Brain histamine H1 receptor occupancy after oral administration of desloratadine and loratadine

Some histamine H1 receptor (H1R) antagonists induce adverse sedative reactions caused by blockade of histamine transmission in the brain. Desloratadine is a second-generation antihistamine for treatment of allergic disorders. Its binding to brain H1Rs, which is the basis of sedative property of antihistamines, has not been examined previously in the human brain by positron emission tomography (PET). We examined brain H1R binding potential ratio (BPR), H1R occupancy (H1RO), and subjective sleepiness after oral desloratadine administration in comparison to loratadine. Eight healthy male volunteers underwent PET imaging with [11C]-doxepin, a PET tracer for H1Rs, after a single oral administration of desloratadine (5 mg), loratadine (10 mg), or placebo in a double-blind crossover study. BPR and H1RO in the cerebral cortex were calculated, and plasma concentrations of loratadine and desloratadine were measured. Subjective sleepiness was quantified by the Line Analogue Rating Scale (LARS) and the Stanford Sleepiness Scale (SSS). BPR was significantly lower after loratadine administration than after placebo (0.504 ± 0.074 vs 0.584 ± 0.059 [mean ± SD], P < 0.05), but BPR after desloratadine administration was not significantly different from BPR after placebo (0.546 ± 0.084 vs 0.584 ± 0.059, P = 0.250). The plasma concentration of loratadine was negatively correlated with BPR in subjects receiving loratadine, but that of desloratadine was not correlated with BPR. Brain H1ROs after desloratadine and loratadine administration were 6.47 ± 10.5% and 13.8 ± 7.00%, respectively (P = 0.103). Subjective sleepiness did not significantly differ among subjects receiving the two antihistamines and placebo. At therapeutic doses, desloratadine did not bind significantly to brain H1Rs and did not induce any significant sedation.

Cardiovascular safety of antihistamines

Histamine is a mediator, which increases the permeability of capillaries during the early phase of allergic reaction, causes smooth muscle contraction of bronchi and stimulates mucous glands in the nasal cavity. Antihistamines are the basis of symptomatic treatment in the majority of allergic diseases, especially allergic rhinitis, allergic conjunctivitis, urticaria and anaphylaxis. The cardiotoxic effects of the two withdrawn drugs, terfenadine and astemizole, were manifested by prolonged QT intervals and triggering torsades de pointes (TdP) caused by blockade of the ‘rapid’ I_Kr potassium channels. These phenomena, however, are not a class effect. This review deals with a new generation of antihistamine drugs in the context of QT interval prolongation risk.

Tap water nasal irrigation in adults with seasonal allergic rhinitis: a randomized double-blind study

Saline nasal irrigation is effective in the treatment of seasonal allergic rhinitis, and sodium chloride itself has no antiallergic effects. The mechanism of saline nasal irrigation depends mainly on washing away allergens and inflammatory mediators induced by allergic reactions. Tap water has the same washing effects as saline. In this study, it was investigated if tap water nasal irrigation was effective in the treatment of seasonal allergic rhinitis. Sixty-four patients diagnosed with seasonal allergic rhinitis were enrolled. Patients were randomized to tap water nasal irrigation group and non-tap water nasal irrigation group for treatment. Patients of both groups were treated with desloratadine. Treatment outcomes were measured using allergic rhinitis Quality of Life (QoL) survey was completed at baseline and after 3 weeks of therapy. There were statistically significant differences in QoL scores between tap water nasal irrigation group and non-tap water nasal irrigation group. The tap water nasal irrigation group had better QoL scores than the non-tap water nasal irrigation group. Tap water nasal irrigation can be a valuable adjuvant therapy for patients with seasonal allergic rhinitis.