Safety and efficacy of once-daily fexofenadine HCl in the treatment of autumn seasonal allergic rhinitis

Efficacy of different oral H1 antihistamine treatments on allergic rhinitis: a systematic review and network meta-analysis of randomized controlled trials

INTRODUCTION

Oral H1 antihistamines are the first-line treatment for patients with allergic rhinitis, while it is uncertain which kind and dosage of the antihistamines are more effective in improving symptoms of patients.

OBJECTIVE

To evaluate the efficacy of different oral H1 antihistamine treatments on patients with allergic rhinitis by performing a network meta-analysis.

METHODS

The search was executed in PubMed, Embase, OVID, the Cochrane Library and ClinicalTrials.gov for relevant studies. The network meta-analysis was performed by using Stata 16.0, and the outcome measures of the analysis were symptom score reductions of patients. Relative risks with 95% Confidence Intervals were used in the network meta-analysis to compare the clinical effect of treatments involved, and Surface Under the Cumulative Ranking Curves (SUCRAs) were also calculated to rank the treatments' efficacy.

RESULTS

18 eligible randomized controlled studies, involving a total of 9419 participants, were included in this meta-analysis. All the antihistamine treatments outperformed placebo in total symptom score reduction and each individual symptom score reduction. According to the results of SUCRA, rupatadine 20 mg and rupatadine 10 mg were ranked relatively high in reductions of total symptom score (SUCRA: 99.7%, 76.3%), nasal congestion score (SUCRA: 96.4%, 76.4%), rhinorrhea score (SUCRA: 96.6%, 74.6%) and ocular symptom score (SUCRA: 97.2%, 88.8%); rupatadine 20 mg and levocetirizine 5 mg were ranked relatively high in reductions of nasal itching score (SUCRA: 84.8%, 83.4%) and sneezing score (SUCRA: 87.3%, 95.4%); loratadine 10 mg was ranked the lowest in each symptom score reduction besides placebo.

CONCLUSION

This study suggests that rupatadine is the most effective in alleviating symptoms of patients with allergic rhinitis among different oral H1 antihistamine treatments involved, and rupatadine 20 mg performs better than rupatadine 10 mg. While loratadine 10 mg has inferior efficacy for patients to the other antihistamine treatments.

Pollen respiratory allergy: Is it really seasonal?

Allergic rhinitis (AR) is a highly prevalent respiratory condition that carries a heavy burden and can have a significant impact on patient quality of life. AR is caused by seasonal or perennial exposure to outdoor pollens and molds as well as indoor allergic triggers. In this review article, we discuss the factors associated with the development of AR throughout the year and the fact that patients with AR need continuous treatment rather than seasonal treatment. Conventionally, AR has been mainly categorized into seasonal AR and perennial AR, but these classes do not seem to be well-adapted. Climate changes, temperature changes, and high carbon dioxide (CO₂) concentration affect the growth of plants and increase the length of pollen seasons and pollen allergenicity. Air pollution aggravates allergic sensitization symptoms in AR sensitized individuals. Due to increased air pollution and indefinite pollen seasons AR symptoms are present throughout the year. Patients with AR often need continuous treatment, which should be considered while making the strategy for treating allergic rhinitis sufferers. Management of AR involves avoiding the allergen, medications for symptomatic relief, anti-inflammatory therapies, and allergy immunotherapy. Although the first-generation H₁-antihistamines reduce AR symptoms, they cause sedation and impair cognitive functions; thus, second-generation antihistamines (ie, levocetirizine, loratadine, bilastine, fexofenadine) are preferred. The efficacy and safety of fexofenadine for the treatment of seasonal allergic rhinitis (SAR) symptoms have been demonstrated by numerous clinical studies, irrespective of the season and underlying allergen. In this review, we discuss the allergic rhinitis classification, the role of climate change, air pollution, and factors contributing to year-round symptoms in patients with AR and the need for continuous pharmacological treatment for management.

Antihistamine effects and safety of fexofenadine: a systematic review and Meta-analysis of randomized controlled trials

Background

As a new generation antihistamine, fexofenadine has been widely used in allergic diseases. However, there is still a lack of collective evidence regarding the antihistamine effects and safety profiles of fexofenadine relative to other antihistamine drugs and placebo. Therefore, we aimed to systematically evaluate the antihistamine effects and safety of fexofenadine.

Methods

An electronic literature search of randomized controlled trials (RCTs) was performed using Embase, Cochrane and PubMed from establishment to January 1st, 2018. RCTs comparing the antihistamine effects or safety (adverse events, sedative effects, and cognitive/psychomotor function) of fexofenadine with either other antihistamines or placebo for healthy subjects and patients with allergy were selected.

Results

Fifty-one studies of 14,551 participants met the inclusion criteria. When compared with the first-generation antihistamines, fexofenadine produced significantly lower adverse events frequency (OR = 0.446; 95% CI: 0.214 to 0.929, P = 0.031), significantly lower sedative effects frequency (OR = 0.265; 95% CI: 0.072 to 0.976, P = 0.046) and significantly less change of all cognitive/psychomotor function. When compared with the second-generation antihistamines, fexofenadine produced significantly marginal sedative effects (OR = 0.59; 95% CI, 0.38 to 0.93; P = 0.02) and significantly less change of most of the cognitive/psychomotor function. When compared with placebo, fexofenadine produced more significant antihistamine effects.

Conclusions

Fexofenadine has a positive antihistamine effect, which is probably no worse than the second-generation antihistamines. Fexofenadine probably has a favorable safety profile, which is more likely better than that of the first-generation antihistamines. There is lack of data to support that fexofenadine has a better overall safety profile compared to the second-generation antihistamines, however, some presently available evidence on sedative effects and certain aspects of cognitive/psychomotor function favors fexofenadine. Therefore, fexofenadine may be worthy of recommendation for safety related workers.

Optimal Duration of Allergic Rhinitis Clinical Trials

OBJECTIVE: Guidelines have been published by the Food and Drug Administration (FDA) and the European Agency for the Evaluation of Medicinal Products (EMEA) for the conduct of seasonal allergic rhinitis (SAR) and perennial allergic rhinitis (PAR) studies. These guidelines have differences regarding the duration of such trials: the FDA suggests 2 weeks for SAR and 4 weeks for PAR but the EMEA suggests 2 to 4 weeks for SAR and 6 to 12 weeks for PAR trials. In the interest of global harmonization, it would be desirable to have a uniform duration of such trials so that investigators, internationally, would be able to readily compare results for various types of treatments based on a single standard. Therefore, we performed an evidence-based review to answer the clinical question, What is the optimal duration for SAR and PAR clinical trials?

METHODS: We performed a MEDLINE search of the published literature from 1995 to the present. We used appropriate search terms, such as allergic rhinitis, seasonal allergic rhinitis, perennial allergic rhinitis, SAR, and PAR, to identify pertinent articles. These articles were reviewed and graded according to the evidence quality.

RESULTS: After an initial screening of more than 300 articles, 138 articles were analyzed thoroughly. No study specifically addressed the question of the optimal duration of SAR or PAR clinical trials.

CONCLUSIONS: We conclude that the current FDA (draft) guidelines calling for a study length of 2 weeks for the assessment of drug efficacy for SAR and 4 weeks for the study of drug efficacy in PAR are appropriate and that longer study periods are not likely to add meaningfully to the assessment of drug efficacy.

A meta-analysis of sublingual allergen immunotherapy and pharmacotherapy in pollen-induced seasonal allergic rhinoconjunctivitis

BACKGROUND

The capacity of sublingual allergen immunotherapy (SLIT) to provide effective symptom relief in pollen-induced seasonal allergic rhinitis is often questioned, despite evidence of clinical efficacy from meta-analyses and well-powered, double-blind, placebo-controlled randomized clinical trials. In the absence of direct, head-to-head, comparative trials of SLIT and symptomatic medication, only indirect comparisons are possible.

METHODS

We performed a meta-analysis of classes of products (second-generation H1-antihistamines, nasal corticosteroids and grass pollen SLIT tablet formulations) and single products (the azelastine-fluticasone combination MP29-02, and the leukotriene receptor antagonist montelukast) for the treatment of seasonal allergic rhinitis in adults, adolescents and/or children. We searched the literature for large (n >100 in the smallest treatment arm) double-blind, placebo-controlled randomized clinical trials. For each drug or drug class, we performed a meta-analysis of the effect on symptom scores. For each selected trial, we calculated the relative clinical impact (according to a previously published method) on the basis of the reported post-treatment or season-long nasal or total symptom scores: 100 × (scorePlacebo - scoreActive)/scorePlacebo.

RESULTS

Twenty-eight publications on symptomatic medication trials and ten on SLIT trials met our selection criteria (total number of patients: n = 21,223). The Hedges' g values from the meta-analyses confirmed the presence of a treatment effect for all drug classes. In an indirect comparison, the weighted mean (range) relative clinical impacts were -29.6% (-23% to -37%) for five-grass pollen SLIT tablets, -19.2% (-6% to -29%) for timothy pollen SLIT tablets, -23.5% (-7% to -54%) for nasal corticosteroids, -17.1% (-15% to -20%) for MP29-02, -15.0% (-3% to -26%) for H1-antihistamines and -6.5% (-3% to -10%) for montelukast.

CONCLUSIONS

In an indirect comparison, grass pollen SLIT tablets had a greater mean relative clinical impact than second-generation antihistamines and montelukast and much the same mean relative clinical impact as nasal corticosteroids. This result was obtained despite the presence of methodological factors that mask the clinical efficacy of SLIT for the treatment of seasonal allergic rhinitis.

Antihistamine therapy in allergic rhinitis

Antihistamines have long been a mainstay in the therapy for allergic rhinitis. Many different oral antihistamines are available for use, and they are classified as first generation or second generation based on their pharmacologic properties and side-effect profiles. The recent introduction of intranasal antihistamines has further expanded the role of antihistamines in the treatment of allergic rhinitis. Certain patient populations, such as children and pregnant or lactating women, require special consideration regarding antihistamine choice and dosing as part of rhinitis therapy.

Allergic conjunctivitis and the impact of allergic rhinitis

Although nasal allergy has been prominent in allergy research, ocular allergy is increasingly recognized as a distinct symptom complex that imposes its own disease burden and reduction in patients' quality of life. In the past year, knowledge of the relationships between allergic conjunctivitis and allergic rhinitis has increased. Allergic conjunctivitis is highly prevalent and has a close epidemiologic relationship with allergic rhinitis. Both conditions also exhibit similar pathophysiologic mechanisms. Pathways of communication are thought to increase the likelihood of an inflammatory reaction at both sites following allergen exposure of nasal or ocular tissue. Clinical trials of intranasal therapies have demonstrated efficacy in allergic conjunctivitis and rhinitis. Newer intranasal steroids decrease ocular symptoms, potentially achieving efficacy by suppressing the naso-ocular reflex, downregulation of inflammatory cell expression, or restoration of nasolacrimal duct patency. Proposed pathophysiologic interactions between allergic rhinitis and ocular allergy underscore the need for therapies with efficacy in both symptom sets.

A review of the efficacy of desloratadine, fexofenadine, and levocetirizine in the treatment of nasal congestion in patients with allergic rhinitis

BACKGROUND

Nasal congestion is the most troublesome symptom of allergic rhinitis (AR). First-generation and older second-generation antihistamines, while effective against nasal itching, sneezing, and rhinorrhea, have limited efficacy in relieving nasal congestion.

OBJECTIVE

This review included nasal challenge studies and clinical trials that reported the effects on nasal congestion of the newer second-generation antihistamines desloratadine, fexofenadine, and levocetirizine.

METHODS

MEDLINE and EMBASE were searched for nasal challenge studies and clinical trials published in English between January 1, 1991, and January 31, 2009, using the following terms, alone or in combination: antihistamines, second-generation antihistamines, allergic rhinitis, intermittent allergic rhinitis, perennial allergic rhinitis, persistent allergic rhinitis, seasonal allergic rhinitis, nasal challenge, nasal blockage, and nasal congestion. Studies that were not active or placebo controlled, that did not evaluate change in nasal congestion scores, or that focused on treatments other than desloratadine, fexofenadine, and levocetirizine for nasal congestion associated with AR were excluded.

RESULTS

Twenty-six clinical trials met the criteria for inclusion in the review. In 11 placebo-controlled trials that included objective assessment of nasal congestion, desloratadine, fexofenadine, and levocetirizine were associated with reductions in the severity of nasal congestion through maintenance of nasal airflow. The mean AUC for nasal airflow over 6 hours was significantly greater with desloratadine compared with placebo in 3 studies (P < 0.05); placebo-controlled trials of fexofenadine and levocetirizine had similar results. In 25 placebo- and active-controlled trials that reported subject-rated symptom scores, the 3 newer antihistamines were efficacious in the treatment of nasal congestion associated with AR. In 10 trials that reported objective and/or subjective measures, desloratadine was associated with significant improvements in nasal congestion compared with placebo (P < or = 0.05), beginning as early as the first 2 hours after allergen challenge. Fexofenadine was associated with significantly lower nasal congestion scores compared with placebo in 4 studies (P <- 0.05); nasal congestion scores were significantly reduced with levocetirizine in 3 placebo-controlled trials (P < or = 0.005).

CONCLUSIONS

In the studies reviewed, desloratadine, fexofenadine, and levocetirizine were effective in relieving the nasal congestion associated with AR compared with placebo. This effect began as early as day 2 and was consistent and progressive throughout treatment. Desloratadine, fexofenadine, and levocetirizine are appropriate options for the treatment of nasal congestion in patients with AR.

Fexofenadine hydrochloride in the treatment of allergic disease: a review

Fexofenadine is a selective, non-sedating H1 receptor antagonist, marketed in the United States since 2000. The FDA approved an oral suspension in 2006, for the treatment of seasonal allergic rhinitis and chronic idiopathic urticaria in children. The tablet, capsule, and oral suspension are bioequivalent. Although fexofenadine does not use P450 CYP 3A4 it does interact with a number of drugs at P-glycoprotein and organic anion transporter polypeptides. The risk of toxicity from other drugs may increase with the administration of fexofenadine. Orange and grapefruit juices reduce the bioavailability of fexofenadine. Fexofenadine has been shown to have an impact on inflammatory mediators, other than histamine, such as decreasing the production of LTC₄, LTD₄, LTE₄, PGE₂, and PGF_2α; inhibiting cyclo-oxygenase 2, thromboxane; limiting iNOS generation of NO; decreasing cytokine levels (ICAM-1, ELAM-1, VCAM-1, RANTES, I-TAC, MDC, TARC, MMP-2, MMP-9, tryptase); and diminishing eosinophil adherence, chemotaxis, and opsonization of particles. These effects may provide benefit to some of the inflammatory responses of an acute allergic reaction and provide a basis for future development of H1 antagonists with stronger anti-inflammatory effects. These studies also support the contention that fexofenadine is effective for the treatment of allergic rhinits and chronic idiopathic urticaria.

Safety and tolerability of fexofenadine hydrochloride, 15 and 30 mg, twice daily in children aged 6 months to 2 years with allergic rhinitis

BACKGROUND

Antihistamines are an established first-line treatment for allergic rhinitis and are widely prescribed in infants for allergic symptoms.

OBJECTIVE

To establish the safety and tolerability of fexofenadine hydrochloride in children aged 6 months to 2 years in 2 studies (T/3001 and T/3002).

METHODS

Both studies had a multicenter, randomized, placebo-controlled design. Mean treatment duration was 8 days. Subjects were randomized (T/3001, n = 174; and T/3002, n = 219) to twice-daily fexofenadine hydrochloride, 15 or 30 mg, or placebo mixed with a standard vehicle.

RESULTS

In the combined population, the incidence of treatment-emergent adverse events (TEAEs) was comparable between groups (placebo, 48.2% [96/199]; fexofenadine hydrochloride, 15 mg, 40.0% [34/85]; and fexofenadine hydrochloride, 30 mg, 35.2% [38/108]). Vomiting was the most common TEAE (placebo, 13.6%; fexofenadine hydrochloride, 15 mg, 14.1%; and fexofenadine hydrochloride, 30 mg, 5.6%). Most TEAEs were unrelated to study medication, as evaluated by investigators; those possibly related to study medication were mild or moderate in intensity. No clinical differences were seen between fexofenadine and placebo for vital signs, electrocardiographic results, or physical examination results.

CONCLUSION

Fexofenadine hydrochloride, 15 or 30 mg, given for a mean duration of 8 days is well tolerated, with a good safety profile, in children aged 6 months to 2 years.

Suppressive activity of fexofenadine hydrochloride on nitric oxide production in-vitro and in-vivo

The aim of this study was to examine the effect of fexofenadine hydrochloride (FEX), a histamine H1-receptor antagonist, on nitric oxide (NO) production in-vitro and in-vivo. Nasal fibroblasts (5 x 10(5) cells per mL) were stimulated with 25 ng mL(-1) tumour necrosis factor-alpha in the presence of various concentrations of FEX. NO levels in 24-h-culture supernatants were measured by the Griess method and levels of inducible nitric oxide synthase (iNOS) mRNA levels in 12-h-cultured cells were measured by ELISA. FEX at more than 0.5 microg mL(-1) suppressed NO production from fibroblasts by inhibiting expression of iNOS mRNA. We also examined whether FEX could suppress NO production induced by lipopolysaccharide (LPS) stimulation in-vivo. BALB/c mice were treated with 5.0 mg kg(-1) LPS i.p. after daily oral doses of FEX, 1.0 mg kg(-1), for 1-3 weeks. Plasma was obtained 6 h later and NO levels measured by the Griess method. Expression of iNOS mRNA in lung tissues was measured by ELISA 6 h after LPS injection. Oral administration of FEX for 2 and 3 weeks, but not 1 week, significantly suppressed NO levels in plasma through the inhibition of iNOS mRNA expression, which were enhanced by LPS stimulation. These results suggest that the attenuating effect of FEX on NO production may be of therapeutic benefit in allergic diseases.

Safety and tolerability of fexofenadine for the treatment of allergic rhinitis in children 2 to 5 years old

BACKGROUND

The safety of fexofenadine has been examined extensively in adults and school-age children. However, the safety of fexofenadine in children younger than 6 years has not been reported to date.

OBJECTIVE

To compare the safety and tolerability of twice-daily fexofenadine hydrochloride, 30 mg, and placebo in preschool children aged 2 to 5 years with allergic rhinitis.

METHODS

This was a multicenter, double-blind, randomized, placebo-controlled, parallel-group study, conducted between February 29, 2000, and June 14, 2001. Participants were randomized to either fexofenadine hydrochloride, 30 mg, or placebo twice daily for a 2-week period. To facilitate dosing, capsule content was mixed with applesauce (approximately 10 mL). Safety assessments depended on date of entry into the study because of an amendment to the protocol. Before the amendment, assessments included physical examination, vital signs reporting (oral temperature, heart rate, and respiratory rate), and adverse event (AE) reporting. After the amendment, safety assessments included laboratory testing (blood chemistry and hematology profiles), physical examination, 12-lead electrocardiography, and vital signs (oral temperature, blood pressure, heart rate, and respiratory rate) and AE reporting.

RESULTS

Treatment-emergent AEs were observed in 116 of 231 participants receiving placebo and 111 of 222 receiving fexofenadine. These AEs were possibly related to study medication in 19 (8.2%) and 21 (9.5%) of the participants receiving placebo and fexofenadine, respectively, and most frequently involved the digestive system. No clinically relevant differences in laboratory measures, vital signs, and physical examinations were observed.

CONCLUSIONS

The findings show that fexofenadine hydrochloride, 30 mg, is well tolerated and has a good safety profile in children aged 2 to 5 years with allergic rhinitis.

Efficacy of diphenhydramine vs desloratadine and placebo in patients with moderate-to-severe seasonal allergic rhinitis

BACKGROUND

Previous studies have shown that diphenhydramine and desloratadine effectively relieve symptoms of seasonal allergic rhinitis (SAR).

OBJECTIVE

To compare the relative efficacy of 50 mg of diphenhydramine hydrochloride, 5 mg of desloratadine, and placebo in relieving symptoms in patients with moderate-to-severe SAR.

METHODS

In this 1-week, multicenter, parallel-group, randomized, double-blind, double-dummy, placebo-controlled study, 610 patients with moderate-to-severe SAR received 50 mg of diphenhydramine hydrochloride 3 times daily, 5 mg of desloratadine once daily, or placebo. Daily 24-hour reflective total nasal symptom scores (TNSSs) (primary end point), total symptom scores, and individual symptom scores were evaluated. A global evaluation of response to treatment was conducted at 2 posttreatment visits.

RESULTS

The mean reduction from baseline in 24-hour reflective TNSSs relative to the placebo response was 77.6% for the diphenhydramine group (P < .001) and 21.0% for the desloratadine group (P = .12). A TNSS between-treatment difference of -1.81 (46.7%; P < .001) was observed when comparing diphenhydramine with desloratadine. A similar between-treatment difference was observed for the 24-hour reflective total symptom score comparing diphenhydramine to desloratadine (-3.35; 45.5%; P < .001). Diphenhydramine provided clinically and statistically significant reductions vs placebo and desloratadine in all individual symptoms, including nasal congestion. Desloratadine had a tendency toward improvement compared with placebo for most individual symptom scores. However, a statistically significant result was reached only for sneezing (-0.27; 33.9%; P = .04).

CONCLUSIONS

Diphenhydramine, 50 mg, given for 1 week provided statistically significant and clinically superior improvements in symptoms compared with 5 mg of desloratadine in patients with moderate-to-severe SAR. Somnolence occurred more frequently with diphenhydramine (22.1%) compared with desloratadine (4.5%) and placebo (3.4%).

Once-daily immediate-release fexofenadine and sustained-release pseudoephedrine combination: a new treatment option for allergic rhinitis

Allergic rhinitis symptoms, in particular nasal congestion, can have a significant impact on patient quality of life, resulting in reduced productivity and daytime sleepiness. Newer-generation antihistamines are commonly used to treat allergic rhinitis; however, in patients with severe congestion, a combination of a newer-generation antihistamine and a decongestant is particularly beneficial. A new once-daily fexofenadine/pseudoephedrine combination has been developed and recently approved in the US. The combination provides an effective, well-tolerated antihistamine and a reliable, sustained-release pseudoephedrine system. In addition, small tablet size and once-daily dosing may provide patients with increased convenience and improve adherence. In summary, the combination of immediate-release fexofenadine/sustained-release pseudoephedrine offers an important additional option for the treatment of allergic rhinitis.

Selecting the Optimal Oral Antihistamine for Patients with Allergic Rhinitis

Allergic rhinitis (AR) is now recognised as a global health problem that affects 10-30% of adults and up to 40% of children. Each year, millions of patients seek treatment from their healthcare provider. However, the prevalence of AR maybe significantly underestimated because of misdiagnosis, under diagnosis and failure of patients to seek medical attention. In addition to the classical symptoms such as sneezing, nasal pruritus, congestion and rhinorrhoea, it is now recognised that AR has a significant impact on quality of life (QOL). This condition can lead to sleep disturbance as a result of nasal congestion, which leads to significant impairment in daily activities such as work and school. Traditionally, AR has been subdivided into seasonal AR (SAR) or perennial AR (PAR). SAR symptoms usually appear during a specific season in which aeroallergens are present in the outdoor air such as tree and grass pollen in the spring and summer and weed pollens in the autumn (fall); and PAR symptoms are present year-round and are triggered by dust mite, animal dander, indoor molds and cockroaches. Oral histamine H(1)-receptor antagonists (H(1) antihistamines) are one of the most commonly prescribed medications for the treatment of AR. There are several oral H(1) antihistamines available and it is important to know the pharmacology, such as administration interval, onset of action, metabolism and conditions that require administration adjustments. When prescribing oral H(1) antihistamines, the healthcare provider must take into account the clinical efficacy and weigh this against the risk of adverse effects from the agent. In addition to the clinical efficacy, potential for improvement in QOL with a particular treatment should also be considered.

Evaluation of the optimal oral antihistamine for patients with allergic rhinitis

Because of its bothersome symptoms, allergic rhinitis (AR) is 1 of the top 10 reasons for patient visits to primary care physicians. This highly prevalent disease also results in loss of productivity, both at work and in school. Oral antihistamines are one of the most frequently prescribed medications for the management of AR and, with several agents available, it is important to discern the specific benefits and detriments of each. To assess the differences in efficacy and safety factors among antihistamines, the Individual therapeutic window of each agent can be used as a comparative reference tool because it defines the dose range over which an antihistamine is efficacious and free of adverse effects. As such, the therapeutic window includes both undesired effects, such as sedation, and desired properties, such as rapid onset of action, long duration of efficacy, broad age range of applicability, and potential to Improve quality of life. Therefore, agents with broad therapeutic windows, based on both efficacy and safety, are expected to be more favorable; this therapeutic window should be understood by the primary care physician when prescribing a medication.

Efficacy and tolerability of newer antihistamines in the treatment of allergic conjunctivitis

Treatment for allergic conjunctivitis has markedly expanded in recent years, providing opportunities for more focused therapy, but often leaving both physicians and patients confused over the variety of options. As monotherapy, oral antihistamines are an excellent choice when attempting to control multiple early-phase, and some late-phase, allergic symptoms in the eyes, nose and pharynx. Unfortunately, despite their efficacy in relief of allergic symptoms, systemic antihistamines may result in unwanted adverse effects, such as drowsiness and dry mouth. Newer second-generation antihistamines (cetirizine, fexofenadine, loratadine and desloratadine) are preferred over older first-generation antihistamines in order to avoid the sedative and anticholinergic effects that are associated with first-generation agents. When the allergic symptom or complaint, such as ocular pruritus, is isolated, focused therapy with topical (ophthalmic) antihistamines is often efficacious and clearly superior to systemic antihistamines, either as monotherapy or in conjunction with an oral or intranasal agent. Topical antihistaminic agents not only provide faster and superior relief than systemic antihistamines, but they may also possess a longer duration of action than other classes including vasoconstrictors, pure mast cell stabilisers, NSAIDs and corticosteroids. Many antihistamines have anti-inflammatory properties as well. Some of this anti-inflammatory effect seen with 'pure' antihistamines (levocabastine and emedastine) may be directly attributed to the blocking of the histamine receptor that has been shown to downregulate intercellular adhesion molecule-1 expression and, in turn, limit chemotaxis of inflammatory cells. Some topical multiple-action histamine H(1)-receptor antagonists (olopatadine, ketotifen, azelastine and epinastine) have been shown to prevent activation of neutrophils, eosinophils and macrophages, or inhibit release of leukotrienes, platelet-activating factors and other inflammatory mediators. Topical vasoconstrictor agents provide rapid relief, especially for redness; however, the relief is often short-lived, and overuse of vasoconstrictors may lead to rebound hyperaemia and irritation. Another class of topical agents, mast cell stabilisers (sodium cromoglicate [cromolyn sodium], nedocromil and lodoxamide), may be considered; however, they generally have a much slower onset of action. The efficacy of mast cell stabilisers may be attributed to anti-inflammatory properties in addition to mast cell stabilisation. In the class of topical NSAIDs, ketorolac has been promoted for ocular itching but has been found to be inferior for relief of allergic conjunctivitis when compared with olopatadine and emedastine. Lastly, topical corticosteroids may be considered for severe seasonal ocular allergy symptoms, although long-term use should be avoided because of risks of ocular adverse effects, including glaucoma and cataract formation.

Similar rapid onset of action and magnitude of effect of fexofenadine and cetirizine as assessed by inhibition of histamine-induced wheal-and-flare reaction

BACKGROUND

Histamine-induced wheal-and-flare studies are useful, objective tests for determining differences in the peripheral H1-receptor blockade activities of antihistamines.

OBJECTIVE

To evaluate the time of occurrence of 95% inhibition of histamine-induced wheal and flare after administration of fexofenadine hydrochloride, 180 mg, or cetirizine, 10 mg.

METHODS

Forty-two volunteers (aged 18-60 years) were included in a randomized, double-blind, crossover study. Skin prick tests were undertaken using histamine (100 mg/mL) before treatment and 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, and 4.0 hours after treatment. Wheal and flare areas were evaluated, and the time to occurrence of 95% inhibition and the frequency of subjects exhibiting 95% inhibition before median time to 95% inhibition were calculated.

RESULTS

Mean +/- SD time to 95% wheal inhibition was 2.46 +/- 0.71 hours with fexofenadine and 2.55 +/- 0.57 hours with cetirizine. The estimated mean difference between fexofenadine and cetirizine (-7 minutes in favor of fexofenadine; 2-sided 95% confidence interval, -21 to +7 minutes) was not statistically significant (P = .34). For wheal, 29% of subjects receiving fexofenadine and 24% receiving cetirizine achieved 95% inhibition before the median time of inhibition (2.5 hours). An exact permutation test yielded a P = .37. For flare, 26% of subjects receiving fexofenadine and 10% receiving cetirizine achieved 95% inhibition before the median time of inhibition (3 hours; P = .12 by exact permutation test).

CONCLUSIONS

Fexofenadine and cetirizine have comparable onset of action times and similar frequencies of inhibition, as evaluated by the occurrence of 95% inhibition of histamine-induced wheal and flare.

Second-Generation Antihistamines

Antihistamines are useful medications for the treatment of a variety of allergic disorders. Second-generation antihistamines avidly and selectively bind to peripheral histamine H1 receptors and, consequently, provide gratifying relief of histamine-mediated symptoms in a majority of atopic patients. This tight receptor specificity additionally leads to few effects on other neuronal or hormonal systems, with the result that adverse effects associated with these medications, with the exception of noticeable sedation in about 10% of cetirizine-treated patients, resemble those of placebo overall. Similarly, serious adverse drug reactions and interactions are uncommon with these medicines. Therapeutic interchange to one of the available second-generation antihistamines is a reasonable approach to limiting an institutional formulary, and adoption of such a policy has proven capable of creating substantial cost savings. Differences in overall efficacy and safety between available second-generation antihistamines, when administered in equivalent dosages, are not large. However, among the antihistamines presently available, fexofenadine may offer the best overall balance of effectiveness and safety, and this agent is an appropriate selection for initial or switch therapy for most patients with mild or moderate allergic symptoms. Cetirizine is the most potent antihistamine available and has been subjected to more clinical study than any other. This agent is appropriate for patients proven unresponsive to other antihistamines and for those with the most severe symptoms who might benefit from antihistamine treatment of the highest potency that can be dose-titrated up to maximal intensity.

Safety and efficacy of oral fexofenadine in children with seasonal allergic rhinitis--a pooled analysis of three studies

Allergic rhinitis is one of the most common clinical conditions in children; however, data regarding the safety of antihistamines in children with seasonal allergic rhinitis are limiting. To evaluate the safety and efficacy of fexofenadine in children with seasonal allergic rhinitis, data were pooled from three, double-blind, randomized, placebo-controlled, parallel-group, 2-week trials in children (6-11 year) with seasonal allergic rhinitis. All studies assessed fexofenadine HCl 30 mg b.i.d.; two studies included fexofenadine HCl at 15 and 60 mg b.i.d. Patients (and investigators) reported any adverse events during the trial. Physical examinations, including measurements of vital signs and laboratory tests, were performed. Efficacy assessments (total symptom score and individual symptom scores) were evaluated. Exposure to fexofenadine HCl 30 mg b.i.d. and to any fexofenadine dose exceeded 10,000 and 17,000 patient days, respectively. Incidences of adverse events, and discontinuations because of adverse events, were low and similar across treatment groups. In the placebo group, 24.4% of subjects reported adverse events compared with 24.1% for fexofenadine HCl 30 mg b.i.d., and 28.4% for all fexofenadine-treated groups. The most common adverse event overall was headache (4.3% placebo; 5.8% fexofenadine HCl 30 mg b.i.d.; and 7.2% any fexofenadine doses). Treatment-related adverse events were similar across treatment groups with no sedative effects. Fexofenadine HCl 30 mg b.i.d. was significantly superior to placebo in reducing the total symptom score and all individual seasonal allergic rhinitis symptoms, including nasal congestion (p < 0.05). Fexofenadine, at doses of up to 60 mg b.i.d., is safe and non-sedating, and fexofenadine HCl 30 mg b.i.d. effectively reduces all seasonal allergic rhinitis symptoms in children aged 6-11 years.

Efficacy and safety profile of fexofenadine HCl: a unique therapeutic option in H1-receptor antagonist treatment

Results of head-to-head comparative trials suggest that fexo-fenadine might offer distinct advantages compared with other antihistamines. Fexofenadine is highly selective for peripheral H(1)-receptors and does not cross the blood-brain barrier, as shown by positron emission tomography. These data support findings that fexofenadine is nonsedating and does not impair performance or driving ability, even at very high doses. In addition, fexofenadine does not interact with muscarinic receptors, which might offer a potential advantage compared with desloratadine, the recently approved active metabolite of loratadine. Fexofenadine is devoid of adverse cardiac effects, and changes in electrocardiogram parameters are not significantly different from those observed with placebo. Fexofenadine has also been shown to have a favorable effect on nasal congestion. This therapeutic advantage might be related to its significant antiallergic properties, ie, the demonstrated ability of fexofenadine to blunt the inflammatory effects of preformed and de novo synthesized mediators at clinically relevant doses in vivo and in vitro. Cumulatively, these benefits distinguish fexofenadine from other antihistamines and make it an optimum therapeutic option for treating allergy-mediated respiratory and dermatologic diseases.

Fexofenadine hydrochloride, 180 mg, exhibits equivalent efficacy to cetirizine, 10 mg, with less drowsiness in patients with moderate-to-severe seasonal allergic rhinitis

BACKGROUND

Previous studies have shown that fexofenadine and cetirizine effectively relieve symptoms of seasonal allergic rhinitis (SAR).

OBJECTIVE

To compare the effects of fexofenadine hydrochloride, 180 mg, and cetirizine, 10 mg, on symptoms, drowsiness, and motivation in patients with moderate-to-severe SAR.

METHODS

In this 2-week multicenter, double-blind, randomized study, 495 subjects with moderate-to-severe SAR received once-daily fexofenadine hydrochloride, 180 mg, or cetirizine, 10 mg, without regard to food intake. Daily 12-hour reflective (AM, PM) and instantaneous (AM) individual symptoms and total symptom score (TSS) were evaluated. Drowsiness and motivation were recorded daily using visual analog scale at 7 AM, 10 AM, and 3 PM.

RESULTS

Between-treatment differences in reduction from baseline in AM instantaneous and 24-hour reflective TSS were -0.18 [95% confidence interval (CI), -0.55 to 0.20) and -0.22 (95% CI, -0.59 to 0.15), respectively. Since CIs for reduction in TSS between treatments fell within a 0.7 margin (defined a priori), treatments were considered statistically equivalent. Patients receiving fexofenadine experienced significantly less overall drowsiness vs baseline than those receiving cetirizine [-2.33 (95% CI, -3.80 to 0.86) vs 0.37 (95% CI, -1.10 to 1.84), P = .0110]. There was a trend toward greater improvements in overall motivation with fexofenadine compared with cetirizine [-2.36 (95% CI, -3.83 to 0.90) vs -0.30 (95% CI, -1.76 to 1.17), P = .0504].

CONCLUSIONS

Once-daily fexofenadine hydrochloride, 180 mg, given for 2 weeks caused statistically and clinically equivalent improvement in symptoms and significantly less drowsiness va baseline, compared with cetirizine, 10 mg, in patients with moderate-to-severe SAR.

Addition of fexofenadine to a topical corticosteroid reduces the pruritus associated with atopic dermatitis in a 1-week randomized, multicentre, double-blind, placebo-controlled, parallel-group study

BACKGROUND

Fexofenadine, a nonsedating, H1-receptor selective antihistamine, exhibits consistent efficacy and safety in the treatment of allergic rhinitis and urticaria. The pruritus associated with atopic dermatitis is considered to be induced, in part, by histamine. Therefore, we thought that fexofenadine may be useful in the relief of pruritus associated with atopic dermatitis.

OBJECTIVE

To compare the efficacy of twice-daily fexofenadine hydrochloride (HCl) 60 mg vs. placebo in reducing the pruritus associated with atopic dermatitis.

METHODS

In this randomized, multicentre, double-blind, placebo-controlled study, patients (aged >or= 16 years) with atopic dermatitis underwent a 1-week placebo lead-in period, followed by randomization to fexofenadine HCl 60 mg twice daily or placebo for 1 week. All patients also received topical treatment with 0.1% hydrocortisone butyrate twice daily throughout the study. The primary efficacy endpoint was mean change in pruritus score from baseline. Patients reflectively recorded pruritus scores twice daily (day and night) using a five-point scale (0 = none; 4 = very severe).

RESULTS

Fexofenadine (n = 201) significantly decreased the severity of pruritus compared with placebo (n = 199) (mean change in score -0.75 (unadjusted 95% confidence interval [-0.88, -0.62]) vs. -0.5 [-0.62, -0.38], respectively; P = 0.0005). This improvement was seen after just 1 day of treatment (P = 0.039) and was maintained throughout the treatment period (P = 0.019). Compared with placebo, fexofenadine significantly improved both diurnal (P = 0.0001) and nocturnal pruritus (P = 0.013). In addition, significantly more patients in the fexofenadine group experienced a reduction in the ratio of pruritus area to body surface area compared with those in the placebo group (P = 0.007). The incidence of adverse events was low and similar across all treatment groups.

CONCLUSIONS

Fexofenadine HCl 60 mg twice daily demonstrated a rapid, significant improvement in the pruritus associated with atopic dermatitis, with a safety profile equivalent to that of placebo.

Relative potency of fexofenadine HCl 180 mg, loratadine 10 mg, and placebo using a skin test model of wheal-and-flare suppression

BACKGROUND

H1-receptor antagonists differ in their ability to produce peripheral H1-blockade. Suppression of histamine-induced flares and wheals is a useful objective test for measuring these differences.

OBJECTIVE

To evaluate the relative potency of fexofenadine HCI 180 mg, loratadine 10 mg, and placebo (PBO) in suppressing histamine-induced flares and wheals and compare the onset, duration, and maximum suppression of histamine achieved with each agent.

METHODS

Thirty healthy volunteers were enrolled in this randomized, double-blind, single-dose, crossover study. Flares and wheals induced by skin-prick testing with histamine 1.8 mg/mL were measured before treatment, every 20 minutes during the first hour after dosing, and thereafter hourly between 2 and 12 hours and between 23 and 25 hours postdose.

RESULTS

Fexofenadine was significantly more effective than loratadine in suppressing the histamine-induced flare response at hours 2 through 7 and 10 through 12 and produced greater flare suppression than did PBO at hours 2 through 25. Onset of flare suppression occurred 2 hours after dosing with fexofenadine and 4 hours after dosing with loratadine. Likewise, fexofenadine was superior to loratadine in suppressing the wheal response from hours 1 through 12 and was more effective than PBO at hours 1 through 12, 24, and 25. Throughout the 25-hour measurement interval, the magnitude of difference in both wheal and flare suppression consistently favored fexofenadine over loratadine.

CONCLUSIONS

In a skin test model of wheal-and-flare suppression, fexofenadine showed rapid distribution into the skin compartment with faster onset of action and greater potency vs loratadine.

Fexofenadine is efficacious and safe in children (aged 6-11 years) with seasonal allergic rhinitis

BACKGROUND

This is the first prospective, randomized, double-blind, placebo-controlled study showing statistical improvement of an H(1)-antihistamine in children with seasonal allergic rhinitis in all symptoms throughout the entire treatment period.

OBJECTIVE

This randomized, placebo-controlled, parallel-group, double-blind study was performed to assess the efficacy and safety of fexofenadine in children with seasonal allergic rhinitis.

METHODS

This study was conducted at 148 centers in 15 countries. Nine hundred thirty-five children (aged 6-11 years) were randomized and treated with either fexofenadine HCl 30 mg (n = 464) or placebo (n = 471) tablets twice a day for 14 days. Individual symptoms (sneezing; rhinorrhea; itchy nose, mouth, throat, and/or ears; itchy, watery, and/or red eyes; and nasal congestion) were assessed at baseline and then daily at 7:00 AM and 7:00 PM (+/-1 hour) during the double-blind treatment period. Each total symptom score was the sum of all symptoms, excluding nasal congestion. The primary efficacy variable was the change from baseline in the average of the daily 12-hour evening reflective total symptom scores throughout the double-blind treatment. Safety was evaluated from adverse-event reporting, vital signs, physical examinations, and clinical laboratory data at screening and study end point.

RESULTS

Fexofenadine was significantly superior to placebo in the primary efficacy analysis (P </=.0001). Individual symptom scores showed statistically significant superiority compared with placebo (P <.05), including nasal congestion in the evening reflective assessment (P <.05). There was no significant difference in adverse events between fexofenadine and placebo, either overall or by causality.

CONCLUSION

The efficacy and safety of the H(1)-antihistamine fexofenadine has been confirmed in this multicenter, multinational study of children aged 6 to 11 years with seasonal allergic rhinitis.

Effects of fexofenadine on the early response to nasal allergen challenge

BACKGROUND

Previous studies using nasal allergen challenge models have shown that terfenadine, an H1 antihistamine, inhibits histamine release during the early response to allergen provocation. Fexofenadine, the active metabolite of terfenadine, has strong H1-antihistaminic activity and no cardiac effects. Clinical studies have documented the efficacy of fexofenadine in the treatment of allergic rhinitis.

OBJECTIVE

To determine whether fexofenadine, like terfenadine, inhibits histamine and tryptase release during the early allergic response.

METHODS

Randomized, double blind, placebo-controlled, two-way crossover study in 20 subjects with seasonal allergic rhinitis, out of their allergy season (median age 27.5 years, 13 males and 7 females). Subjects were medicated with either placebo or fexofenadine 180 mg orally daily for 1 week followed by nasal challenge with allergen. After each challenge, sneezes and nasal symptoms were recorded, and a nasal lavage was obtained for the assay of albumin, an indicator of vascular permeability, and histamine and tryptase, indicators of mast cell degranulation.

RESULTS

When patients were on placebo, allergen challenges led to significant increases in all measured parameters compared with the sham challenges with diluent. Treatment with fexofenadine resulted in inhibition of allergen-induced symptoms and increased vascular permeability, but not the release of histamine and tryptase.

CONCLUSION

Fexofenadine is an effective H1 antihistamine, but in contrast to its parent compound, terfenadine, it does not affect the release of the mast cell mediators histamine and tryptase.

Next generation antihistamines: therapeutic rationale, accomplishments and advances

Antihistamines, among the most commonly prescribed drugs in the world, have evolved considerably since the first generation was introduced >50 years ago. The first generation antihistamines (e.g., chlorpheniramine, diphenhydramine, promethazine and hydroxyzine) are still widely available and in use today. These drugs have considerable sedative effects caused by their ability to cross the blood-brain barrier. The next generation of antihistamines to emerge in the market were devoid of these sedative effects; however, two (terfenadine and astemizole) have shown rare but lethal cardiotoxic side effects. The third generation antihistamines, metabolites of the earlier drugs, have demonstrated no cardiac effects of the parent drugs and are at least as potent. Many have exhibited superior pharmacokinetic and pharmacological profiles, including an improved onset of action and duration of effect. The clinical benefit of these newer oral antihistamines will clearly help improve the quality of life of patients with chronic allergies.

Evaluation of cytokines in nasal secretions after nasal antigen challenge: lack of influence of antihistamines

BACKGROUND

Previous studies of inflammation in allergic rhinitis using nasal irrication have been unsatisfactory because of 1) poor reproducibility; 2) the tendency of irrigation to overdilute mediators; and 3) the failure of this technique to evaluate interstitial concentrations of relevant mediators. For this study we used filter paper as a matrix to collect nasal secretions in patients undergoing nasal antigen challenge.

OBJECTIVE

To evaluate inflammatory mediators of allergen-induced rhinitis during a clinical trial of fexofenadine.

METHODS

Subjects evaluated at a referral medical center were placed on traditional dosing of fexofenadine at 60 mg, twice daily, or placebo in a double-blind, crossover fashion for 1 week before the nasal challenge. Nasal challenge was performed with nasal insufflation of either 1,000 AU timothy or 0.1 mL ragweed (1:100 wt/vol) extract outside the pollen season. Nasal secretions were collected at baseline and then at 2, 4, and 6 hours after nasal challenge. Secretions were evaluated for expression of the cellular adhesion molecule-1, tumor necrosis factor (TNF)-alpha, interleukin (IL)-4, IL-10, macrophage inflammatory protein (MIP)-1alpha, and granulocyte-macrophage colony-stimulating factor (GM-CSF) using commercially available enzyme-linked immunoadsorbent assay kits. Patients' symptom scores were evaluated during the nasal challenge.

RESULTS

Significantly (P < 0.05) increased peak levels of TNF-alpha, IL-4, IL-10, and MIP-1alpha were detected after antigen challenge as compared with baseline levels. There was a nonsignificant trend toward an increase in GM-CSF after antigen challenge (P = 0.07). There was no difference in the peak levels of TNF-alpha, IL-4, IL-10, MIP-1alpha, or GM-CSF measured when patients were on fexofenadine versus placebo. Finally, there were no significant differences in patients' symptom scores during antigen challenge when subjects were on fexofenadine versus placebo.

CONCLUSIONS

Collection of nasal secretions using a filter paper matrix provides a reproducible model for accurately detecting and evaluating changes in cytokine levels after nasal challenge. Cytokine levels tend to peak 3 to 4 hours after antigen challenge. Standard doses of fexofenadine do not seem to have a mitigating effect on the production of these cytokines. Symptoms of allergic rhinitis using this type of antigen challenge did not differ from treatment with fexofenadine versus placebo.

Safety of fexofenadine in children treated for seasonal allergic rhinitis

BACKGROUND

The incidence of allergic rhinitis in children is increasing.

OBJECTIVE

To evaluate the safety of fexofenadine HCI in children ages 6 through 11 years for treatment of seasonal allergic rhinitis.

METHODS

Two large, double-blind, randomized, placebo-controlled, parallel studies with identical protocols included patients with a positive skin test to fall allergen(s) and allergic rhinitis symptoms. Patients were randomized to receive fexofenadine 15, 30, or 60 mg or placebo twice daily for 2 weeks after a 1-week placebo lead-in. Safety was evaluated through adverse event reporting, electrocardiograms, and pre- and posttreatment laboratory panels and physical examinations.

RESULTS

A total of 875 patients from both studies were eligible for safety analyses. Ten patients (5 on placebo, 5 on fexofenadine) discontinued because of an adverse event; no event that resulted in discontinuation was judged to be caused by study medication. Incidence of adverse events was similar in active and placebo groups, and did not increase with increasing fexofenadine dose: 36.2% (83 of 229) in the placebo group versus 35.3% (79 of 224), 36.8% (77 of 209), and 34.7% (74 of 213) in the 15, 30, and 60 mg twice-daily fexofenadine groups, respectively. Headache was the most commonly reported adverse event (6.6%, 8.0%, 7.2%, and 9.4% in the placebo, 15, 30, 60 mg twice-daily fexofenadine groups, respectively). Clinical, vital sign, electrocardiogram, and laboratory measures were similar in active and placebo groups. There was no statistically significant mean change from baseline in any electrocardiogram parameter after fexofenadine treatment.

CONCLUSIONS

Fexofenadine, 15, 30, and 60 mg twice daily, was safe and well tolerated in this large pediatric patient population.

Decongestant efficacy of desloratadine in patients with seasonal allergic rhinitis

Recent advances in experimental immunologic approaches to seasonal allergic rhinitis (SAR) have led to a shift in the concepts of its pathogenesis. The conventional view of SAR as a local response to inhaled allergens has largely given way to a new view of this disorder as a systemic condition with local tissue manifestations. This concept, together with an increasing recognition of specific mediators' distinct roles in driving the early- and late-phase allergic responses, has opened multiple lines of therapeutic attack within the allergic cascade. Potent inhibition of inflammatory mediator release at distinct points in this cascade is conferred by desloratadine. In addition to the familiar range of SAR symptoms amenable to antihistamine therapy, desloratadine uniquely attenuates patient ratings of nasal congestion. This novel, nonsedating histamine H1-receptor antagonist is the only once-daily antiallergic product with a consistent decongestant effect that begins within hours of the first morning dose and is sustained for the entire treatment period.

Twenty-four hours of activity of cetirizine and fexofenadine in the skin

BACKGROUND

Cetirizine and fexofenadine, the active metabolite of terfenadine, are powerful and well-tolerated H1 receptor antagonists effective in the treatment of skin and nose atopic diseases.

OBJECTIVE

We have compared the pharmacodynamic activity of the two antihistamines at therapeutic dosages, cetirizine at 10 mg and fexofenadine at 120 mg and 180 mg, on histamine-induced skin reactivity during a 24-hour period after single intake.

METHODS

Twenty-six healthy volunteers participated in a randomized, double-blind, crossover, placebo-controlled study. The areas of wheal and flare induced by histamine (100 mg/mL) administered by prick test were measured at 0, 0.5, 1, 2, 4, 6, 8, 10, 12, and 24 hours postdose. Statistical analysis of the areas under the time-response curves was performed by a Friedman's ANOVA followed by a Wilcoxon test and Bonferroni's correction.

RESULTS

The three active treatments clearly inhibited the wheal and flare areas throughout the 24-hour period compared with placebo. Maximal inhibition occurred at 4 hours postdose. Between 4 and 24 hours postdose, the time course of inhibition by cetirizine differed significantly (P < 0.001) from that by fexofenadine at either dose, which did not differ from each other. At 24 hours, fexofenadine inhibited <40% of the skin reaction, whereas cetirizine reduced 60% of the wheal. The duration of effect, considered as the time for wheal to be inhibited by at least 70%, also significantly favored cetirizine (19 hours) compared with fexofenadine (9.3 and 8.5 hours for 180 and 120 mg, respectively; P < 0.001). Consistency of activity was evaluated by the frequency of total inhibition of the wheal (> or =95%). Consistency was observed in 26 of 26 participants for cetirizine, 21 of 26 for fexofenadine, 180 mg, and 10 of 26 for fexofenadine, 120 mg (P < 0.001), suggesting better consistency for cetirizine. There was no serious adverse event.

CONCLUSIONS

Our study clearly shows better duration of action and consistency of the antihistaminic activity of cetirizine compared with fexofenadine (120 and 180 mg) in the histamine-induced skin reaction during a 24-hour period.

Comparison of the efficacy, safety and quality of life provided by fexofenadine hydrochloride 120 mg, loratadine 10 mg and placebo administered once daily for the treatment of seasonal allergic rhinitis

BACKGROUND

As there have been no previously published studies, this multinational, double-blind, randomized, placebo-controlled, parallel group study compared the efficacy, safety and impact on quality of life (QoL) in seasonal allergic rhinitis patients (SAR) of fexofenadine and loratadine (with placebo), when administered once daily.

METHODS

Six hundred and eighty-eight SAR patients were randomized to receive fexofenadine HCl 120 mg, loratadine 10 mg or placebo, once daily for 2 weeks. The key parameters were the change from baseline in: mean 24-h reflective total symptom scores (TSS); sum of four individual symptom scores, excluding nasal congestion; instantaneous TSS; individual symptom scores including nasal congestion; and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ). Adverse events were recorded.

RESULTS

Mean 24-h reflective and instantaneous TSS were significantly reduced by both fexofenadine HCl (both P </= 0.0001) and loratadine (P </= 0.001 and P </= 0.005, respectively) compared with placebo (n = 639). Among individual symptom scores, fexofenadine HCl was significantly better than loratadine in improving 24-h reflective itchy, watery, red eyes, as well as relieving nasal congestion (P </= 0.05 for both). Fexofenadine HCl was also significantly better than loratadine (P </= 0.03) and placebo (P </= 0.005) in improving QoL, and the differences were of a magnitude considered to be clinically relevant. Loratadine had no statistically significant effect on QoL compared with placebo. The incidence of adverse events was low and similar across all treatment groups.

CONCLUSION

Fexofenadine HCl and loratadine administered once daily are effective and well tolerated in SAR. In this study, fexofenadine HCl was significantly more effective than loratadine in relieving eye symptoms and nasal congestion. Furthermore, fexofenadine was significantly better than loratadine in improving QoL.

Allergic rhinitis: treating the adult

Allergic rhinitis is now recognized as a chronic medical condition that markedly affects patient quality of life and is a cause of substantial medical care expenditures. Effective treatment of adults with allergic rhinitis usually requires an integrated regimen that combines allergen avoidance measures, pharmacotherapy, and possible specific-allergen immunotherapy. This approach can control bothersome symptoms with minimal adverse effects in most patients. New medications, such as anti-immunoglobulin E therapy and cytokine antagonists, may provide relief to patients who are refractory to or do not tolerate currently available treatments.

Fexofenadine: a review of its use in the management of seasonal allergic rhinitis and chronic idiopathic urticaria

Fexofenadine, the active metabolite of terfenadine, is a selective histamine H1 receptor antagonist that does not cross the blood brain barrier and appears to display some anti-inflammatory properties. Fexofenadine is rapidly absorbed (onset of relief < or = 2 hours) and has a long duration of action, making it suitable for once daily administration. Clinical trials (< or = 2 weeks' duration) have shown fexofenadine 60 mg twice daily and 120 mg once daily to be as effective as loratadine 10 mg once daily, and fexofenadine 120 mg once daily to be as effective as cetirizine 10 mg once daily in the overall reduction of symptoms of seasonal allergic rhinitis. When given in combination, fexofenadine and extended release pseudoephedrine had complementary activity. Fexofenadine was effective in relieving the symptoms of sneezing, rhinorrhoea, itchy nose palate or throat, and itchy, watery, red eyes in patients with seasonal allergic rhinitis. There were often small improvements in nasal congestion that were further improved by pseudoephedrine. Fexofenadine produced greater improvements in quality of life than loratadine to an extent considered to be clinically meaningful, and enhanced patients' quality of life when added to pseudoephedrine treatment. Although no comparative data with other H1 antagonists exist, fexofenadine 180 mg once daily was effective in reducing the symptoms of chronic idiopathic urticaria for up to 6 weeks. Fexofenadine was well tolerated in clinical trials in adults and adolescents and the adverse event profile was similar to placebo in all studies. The most frequently reported adverse event during fexofenadine treatment was headache, which occurred with a similar incidence to that seen in placebo recipients. Fexofenadine does not inhibit cardiac K+ channels and is not associated with prolongation of the corrected QT interval. When given alone or in combination with erythromycin or ketoconazole, it was not associated with any adverse cardiac events in clinical trials. As it does not cross the blood brain barrier, fexofenadine is free of the sedative effects associated with first generation antihistamines, even at dosages of up to 240 mg/day.

CONCLUSIONS

fexofenadine is clinically effective in the treatment of seasonal allergic rhinitis and chronic idiopathic urticaria for which it is a suitable option for first-line therapy. Comparative data suggest that fexofenadine is as effective as loratadine or cetirizine in the treatment of seasonal allergic rhinitis. In those with excessive nasal congestion the combination of fexofenadine plus pseudoephedrine may be useful. In clinical trials fexofenadine is not associated with adverse cardiac or cognitive/psychomotor effects.

Once-daily fexofenadine HCl improves quality of life and reduces work and activity impairment in patients with seasonal allergic rhinitis

BACKGROUND

Fexofenadine HCl (Allegra, Telfast) is approved in the US for twice-daily dosing for treatment of seasonal allergic rhinitis.

OBJECTIVE

To determine the effect of once-daily fexofenadine HCl on patient-reported quality of life and impairment at work, in the classroom, and in daily activities due to seasonal allergic rhinitis symptoms.

METHODS

This placebo-controlled, double-blind, randomized study included patients aged 12 to 65 years with moderate-to-severe seasonal allergic rhinitis symptoms. Outcomes were assessed using self-administered questionnaires at baseline, week 1, and week 2. Outcome measures included change from baseline in: overall Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) score; individual RQLQ domain scores; work, classroom, and daily activity impairment measured using the Work Productivity and Activity Impairment (WPAI) instrument; and ratings in 3 generic health domains from the SF-36 Health Survey.

RESULTS

Intent to treat efficacy analyses included 845 patients from 40 sites. Patients receiving either 120 or 180 mg QD fexofenadine HCl reported significantly greater improvement (P < or = .006) in overall RQLQ score than patients receiving placebo. Similarly, both fexofenadine treatment groups reported significantly greater reductions in overall work impairment and daily activity impairment compared with the placebo group (P < or = .004). There was a trend for improvement in classroom impairment with fexofenadine treatment, although differences from placebo were not statistically significant. Generic health measures demonstrated fexofenadine HCl treatment had a positive effect on general health.

CONCLUSION

Once-daily fexofenadine HCl, 120 or 180 mg, significantly improved patient-reported quality of life and reduced performance impairment in work and daily activities due to seasonal allergic rhinitis symptoms compared with placebo.