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

Current concepts and therapeutic strategies for allergic rhinitis in school-age children

BACKGROUND

Allergic rhinitis (AR) is a common debilitating disorder that can adversely affect the quality of life and the academic performance of school-age children. Symptoms during the day can hamper concentration and lead to learning problems. Nocturnal symptoms can cause sleep loss and secondary daytime fatigue, further undermining a child's ability to function well during the school day Oral antihistamines are the foundation of pharmacologic therapy, but there are important differences between the agents.

OBJECTIVE

The purpose of this review is to provide an overview of the diagnostic and treatment challenges posed by AR in school-age children. The paper discusses and compares the available treatment modalities for this age group, with a focus on their beneficial and adverse effects.

METHODS

Pertinent articles were identified in the literature through a MEDLINE search (1990-2003). Keywords used were antihistamines cetirizine fexofenadine loratadine desloratadine intranasal corticosteroids and CNS effects. Results of numerous clinical trials of first-generation early second-generation and the newer antihistamines were identified.

RESULTS

This review established that the socioeconomic costs of AR are considerable. In children aged > or =12 years, direct US expenditures (eg, physician visits, medications) in 1996 amounted to $2.3 billion. Indirect costs measured by variables such as missed school days and poor performance also have an impact Major concerns include underdiagnosis and inadequate treatment, increasing the risk of serious comorbid conditions such as asthma. Advantages and drawbacks of antihistamines show that first-generation agents (eg, hydroxyzine) are effective and readily available over the counter, but are associated with sedation and the potential for suboptimal dosing. Newer agents, such as cetirizine, loratadine, desloratadine, and fexofenadine are effective and safer than the older drugs tie, no cardiotoxicity and less sedation). Of these, fexofenadine has been shown to be beneficial and nonsedating, even at higher-than-recommended doses. Other therapies reviewed include intranasal corticosteroids and leukotriene modifiers.

CONCLUSIONS

AR has a considerable negative impact on children in terms of their physical, social, and psychological well-being and academic performance. An appropriate treatment must be effective and tolerable. Of particular importance for enhancing treatment adherence in the school-age population are pleasant taste and ease of use of medication. A drug that has minimal or no sedative or anticholinergic effects is optimal.

Why generic and disease-specific quality-of-life instruments should be used together for the evaluation of patients with persistent allergic rhinitis

BACKGROUND

The importance of assessing health-related quality of life (HRQL) of patients with allergic rhinitis (AR) has been well established, but the specific roles of rhinitis-specific or general health instruments have not been delineated.

OBJECTIVE

We analysed the psychometric properties of a disease-specific instrument, the Rhinoconjunctivitis Quality-of-Life Questionnaire (RQLQ) and the general health instrument, the Medical Outcome Short-Form 36 (SF-36) as they are employed in combination in patients with persistent AR in clinical practice.

METHOD

We analysed the data collected from a prospective study of 43 newly diagnosed patients with persistent AR and 44 controls. We interviewed the patients four times, at baseline, weeks 4, 8 and 10.

RESULTS

The RQLQ and SF-36 have good discriminative property, internal consistency, and test-retest reliability. The RQLQ is superior to the SF-36 as an evaluative instrument because more of its domains respond to change, the magnitude of change was greater, and the response was faster. The SF-36 is more susceptible to floor and ceiling effects. Both instruments are unsuitable for mildly symptomatic patients based on Rasch model analysis. Each questionnaire assesses a distinct and significant portion of the total HRQL of persistent AR.

CONCLUSION

The SF-36 and RQLQ are good for discriminating rhinitis patients from controls, but the former is poor for detecting changes in QOL. Both are inappropriate for mildly symptomatic patients. Each instrument measures non-overlapping halves of the measurable HRQL. For an assessment of the HRQL in persistent AR that is complete and responsive both instruments should be employed together.

Fexofenadine Improves the Quality of Life and Work Productivity in Japanese Patients with Seasonal Allergic Rhinitis during the Peak Cedar Pollinosis Season

BACKGROUND

Although currently in its infancy, quality of life (QOL) research in Japan is rapidly expanding and is expected to become a standard outcome measure in clinical trials. In Japan, QOL has not previously been assessed in patients with allergic rhinitis (AR); we report the first clinical study applying the recently validated Japanese translations of the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) and Work Productivity and Activity Impairment-Allergy Specific (WPAI-AS) Questionnaire to assess the effects of the oral antihistamine, fexofenadine, on QOL and work productivity due to cedar pollinosis.

PATIENTS AND METHODS

A randomized, double-blind, placebo-controlled, single-site study was conducted during the peak cedar pollinosis season in Japan. After a 7-day run-in period, subjects were randomized to receive fexofenadine HCl 60 mg twice daily (bid) or placebo for 2 weeks.

RESULTS

Overall, 206 Japanese subjects with AR were included in the intention-to- treat population (fexofenadine, n = 104, and placebo, n = 102). Fexofenadine statistically significantly improved overall QOL compared with placebo (p = 0.005) and improvements were reported in the RQLQ domains: activities (p = 0.047), practical problems (p = 0.003), nasal symptoms (p = 0.003) and eye symptoms (p </= 0.001). Clinically significant improvements in practical problems, eye symptoms and activity limitations, exceeding the 0.05 level, were observed with fexofenadine. These improvements in QOL were associated with significant symptom relief (p < 0.001 vs. placebo). Improvements in impairment at work were also reported with fexofenadine.

CONCLUSION

In Japan, this is the first clinical study to show that fexofenadine HCl (60 mg b.i.d.) improves overall QOL and work productivity in patients with seasonal AR using validated Japanese instruments.

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.

The effect of improving primary care depression management on employee absenteeism and productivity. A randomized trial

OBJECTIVE

To test whether an intervention to improve primary care depression management significantly improves productivity at work and absenteeism over 2 years.

SETTING AND SUBJECTS

Twelve community primary care practices recruiting depressed primary care patients identified in a previsit screening.

RESEARCH DESIGN

Practices were stratified by depression treatment patterns before randomization to enhanced or usual care. After delivering brief training, enhanced care clinicians provided improved depression management over 24 months. The research team evaluated productivity and absenteeism at baseline, 6, 12, 18, and 24 months in 326 patients who reported full-or part-time work at one or more completed waves.

RESULTS

Employed patients in the enhanced care condition reported 6.1% greater productivity and 22.8% less absenteeism over 2 years. Consistent with its impact on depression severity and emotional role functioning, intervention effects were more observable in consistently employed subjects where the intervention improved productivity by 8.2% over 2 years at an estimated annual value of US 1982 dollars per depressed full-time equivalent and reduced absenteeism by 28.4% or 12.3 days over 2 years at an estimated annual value of US 619 dollars per depressed full-time equivalent.

CONCLUSIONS

This trial, which is the first to our knowledge to demonstrate that improving the quality of care for any chronic disease has positive consequences for productivity and absenteeism, encourages formal cost-benefit research to assess the potential return-on-investment employers of stable workforces can realize from using their purchasing power to encourage better depression treatment for their employees.

The validity and accuracy of the Work Productivity and Activity Impairment questionnaire--irritable bowel syndrome version (WPAI:IBS)

BACKGROUND

Irritable bowel syndrome is a common chronic functional gastrointestinal disorder characterized by recurrent abdominal pain and discomfort associated with alterations in bowel habit. Irritable bowel syndrome affects patients' quality of life and increases productivity loss.

AIM

To assess validity and accuracy of the Work Productivity and Activity Impairment questionnaire in irritable bowel syndrome as a tool for quantifying the effects of irritable bowel syndrome on productivity and daily activities.

METHODS

Validity and accuracy were evaluated in 135 irritable bowel syndrome patients relative to three measures of irritable bowel syndrome disease severity; a debriefing questionnaire; retrospective diary; Work Limitations Questionnaire, and an activity impairment measure (Dimensions of Daily Activities).

RESULTS

Symptom severity scores, diary scores, Work Limitations Questionnaire and Dimensions of Daily Activities were significant predictors of work productivity and activity impairment questionnaire in irritable bowel syndrome measures of work time missed, and work and activity productivity loss (P = 0.04 to < 0.0001). Impairment due to irritable bowel syndrome was estimated to be 2.9-4.3% for work time missed and 22-32% for impairment at work, the equivalent of 9.7 -14 h lost productivity per week. Activity impairment was 24-41%.

CONCLUSIONS

Discriminative validity of the Work Productivity and Activity Impairment questionnaire in irritable bowel syndrome was established, making it the only validated tool for measuring the relative differences between disease severity groups and quantifying work productivity loss and activity impairment in irritable bowel syndrome patients.

Change in Health Risks and Work Productivity Over Time

We sought to examine the relationship between changes in health risks and changes in work productivity. Pre- and postanalysis was conducted on 500 subjects who participated in a wellness program at a large national employer. Change in health risks was analyzed using McNemar chi-square tests, and change in mean productivity was analyzed using paired t tests. A repeated measures regression model examined whether a change in productivity was associated with a change in health risks, controlling for age and gender. Individuals who reduced one health risk improved their presenteeism by 9% and reduced absenteeism by 2%, controlling for baseline risk level, age, gender, and interaction of baseline risk and risk change. In conclusion, reductions in health risks are associated with positive changes in work productivity. Self-reported work productivity may have utility in the evaluation of health promotion programs.

A review of self-report instruments measuring health-related work productivity: a patient-reported outcomes perspective

Health impairment often leads to work impairment in the form of both absenteeism and presenteeism (i.e. reduced productivity while at work). Several self-report productivity instruments have been designed over the past few years to measure the impact of illness on productivity at work and/or in non-work activities. In a review of the literature we identified six generic subjective instruments - the Endicott Work Productivity Scale, Health and Labor Questionnaire, Health and Work Questionnaire, Health and Work Performance Questionnaire, Work Limitations Questionnaire (WLQ) and the Work Productivity and Activity Impairment Questionnaire (WPAI) - that could theoretically be used in any working population. These instruments were usually validated against other subjective measures (such as health-related QOL). Each productivity instrument has benefits in certain research settings, but the psychometric properties of the WPAI have been assessed most extensively. It was the most frequently used instrument and has also been modified to measure productivity reductions associated with specific diseases (e.g. allergic rhinitis, gastro-oesophageal reflux disease, chronic hand dermatitis). The WLQ has also been tested extensively to measure the general health impact and impact of specific conditions. Two migraine-specific subjective instruments were also identified: the Migraine Disability Assessment questionnaire and the Migraine Work and Productivity Loss Questionnaire, of which the latter was found to have better psychometric properties. Productivity outcomes are useful in that they characterise the impact of an illness in the workplace and show the effect of treatment on productivity. Evidence of psychometric properties and generalisability of different instruments was found to a varying degree. Thus, further research is needed to assess the accuracy and usefulness of individual instruments in certain research settings. Health-related productivity has been increasingly recognised as an important component of the burden of illness associated with a given disease; without it, one cannot reliably assess this burden.

The economic burden of allergic rhinitis: a critical evaluation of the literature

Although a large number of economic analyses of allergic rhinitis have been published, there are relatively few empirically based studies, particularly outside the US. The majority of these analyses can be classified as burden-of-illness studies. Most estimates of the annual cost of allergic rhinitis range from dollars US 2-5 billion (2003 values). The wide range of estimates can be attributed to differences in identifying patients with allergic rhinitis, differences in cost assignment, limitations associated with available data and difficulties in assigning indirect costs (associated with reduced productivity) of allergic rhinitis. Approximately one-third of burden-of-illness studies include direct and indirect costs of allergic rhinitis, about one-third focus on direct costs only, and the remaining one-third focus exclusively on indirect costs due to reduced productivity. Indirect costs attributable to allergic rhinitis were higher in studies only estimating indirect costs (dollars US 5.5-9.7 billion) than in those estimating both direct and indirect costs (dollars US 1.7-4.3 billion). Although there are many economic evaluations of allergic rhinitis treatments in the published medical literature, very few represent formal cost-effectiveness evaluations that compare the incremental costs and benefits of alternative treatment strategies. Those that are incremental cost-effectiveness analyses have several limitations, including small samples, short study periods and the lack of a standardized measure of effectiveness. To date, the medical literature is lacking a comprehensive economic evaluation of general treatment strategies for allergic rhinitis. In undertaking such an analysis, serious consideration must be given to the study population of interest, the choice of appropriate comparators, the perspective from which the analysis is conducted, the target audience, the changing healthcare marketplace and the selection of a measure of effectiveness that incorporates both positive and negative aspects of treatments for allergic rhinitis. Future work would benefit from the development of a consensus on a summary measure of effectiveness that could be used in cost-effectiveness analyses of therapies for allergic rhinitis as well as additional empirical work to measure the association between severity of disease and its impact on worker productivity.

Comparative study of acute effects of single doses of fexofenadine, olopatadine, d-chlorpheniramine and placebo on psychomotor function in healthy volunteers

Since most classical (first-generation) antihistamines have undesirable sedative effects on the central nervous system (CNS), newer (second-generation) antihistamines have been developed to relieve the sedative effects and to improve the patient's quality of life. However, the psychomotor profiles of second-generation antihistamines are not fully elucidated. In this randomized, double-blind, crossover study, the acute effects of single doses of second-generation antihistamines, fexofenadine (120 mg) and olopatadine (10 mg), on cognitive and psychomotor performance were investigated in comparison with those of placebo and d-chlorpheniramine (4 mg), a first-generation antihistamine, using objective and subjective assessments, in 11 healthy Japanese volunteers. In a battery of psychomotor tests, d-chlorpheniramine impaired tracking ability in the compensatory tracking task and caused a reduction in behavioural activity as continuously measured by wrist actigraphy. Olopatadine, like d-chlorpheniramine, reduced the behavioural activity, while fexofenadine had no effect in any of the tests. No significant changes in the subjects' self-ratings of drowsiness were found with the three antihistamines. These results suggest that d-chlorpheniramine and olopatadine, but not fexofenadine, produce sedative effects on psychomotor performance, and that the CNS profile of fexofenadine is different from that of olopatadine.

Effects of triamcinolone on quality of life in patients with persistent allergic rhinitis

OBJECTIVE

To study the effects of triamcinolone acetonide on health-related quality of life (HRQL) in adult patients with allergic rhinitis.

METHODS

This study was conducted in South Africa as a placebo-controlled, multicenter, randomized, double-blind study. Following a 7-day baseline run-in, patients were treated for 28 days with either triamcinolone or placebo. Interviewer-assisted quality-of-life assessments were conducted using the Juniper Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ). Total symptom scores, including nasal congestion, were measured using daily diary cards.

RESULTS

A total of 337 patients were recruited and 253 patients completed the study per protocol, of which 55 had seasonal allergic rhinitis (SAR) and 198 had persistent allergic rhinitis (PAR). Improvements in the mean scores per area of the RQLQ were significantly better with triamcinolone compared with placebo for the entire study group for activities (P = .04 at visit 4) and sleep, nasal symptoms, emotional problems, and overall score (P = .002, P = .04, P = .03, and P = .04, respectively, at visit 3). When the patients with SAR were separated from the patients with PAR in the analysis, improvement with triamcinolone was better than placebo only in the PAR patients. The overall investigator and patient assessments of relief favored triamcinolone.

CONCLUSIONS

Triamcinolone given for 4 weeks improves symptom scores and HRQL in patients with allergic rhinitis. The ability of triamcinolone to relieve nasal congestion symptoms in PAR patients was correlated with improvements in HRQL.

Pharmaceuticals and worker productivity loss: a critical review of the literature

Many chronic illnesses that affect the working population can cause losses in productivity. The extent to which these productivity losses can be reduced by pharmacological treatment is of particular interest to employers, who bear the productivity costs and subsidize the cost of employees' health care. In the past several years, the effects of pharmaceuticals on productivity losses have been tested in numerous studies, including randomized, double-blind, placebo-controlled trials. In this article, we summarize and critically review these studies and, where appropriate, provide quantitative overviews. The evidence is very good for about a dozen drug classes that pharmaceuticals reduce productivity losses caused by respiratory illnesses (ie, asthma, allergic disorders, bronchitis, upper respiratory infections, and influenza) diabetes, depression, dysmenorrhea, and migraine. We also discuss the calculation of productivity costs, reductions in which may partially or completely offset the costs of treatment. This information should be helpful to occupational physicians who are increasingly providing recommendations on employer benefit plan designs and pharmaceutical benefits.

Effects of fexofenadine, diphenhydramine, and placebo on performance of the test of variables of attention (TOVA)

OBJECTIVE

To determine the effects of diphenhydramine 50 mg and fexofenadine 180 mg on cognitive performance using the Test of Variables of Attention (TOVA), and to ascertain whether the TOVA was sufficiently sensitive to differentiate between the effects of these first- and second-generation H1-receptor antagonists on performance.

STUDY DESIGN

The study used a double-blind, placebo-controlled, randomized, crossover design. Forty-two subjects completed four separate TOVA tests: at baseline and after administration of placebo, diphenhydramine 50 mg, and fexofenadine 180 mg. On each occasion, subjects rated subjective feelings of drowsiness on a visual analog scale (VAS) before taking the TOVA.

RESULTS

Compared with placebo, diphenhydramine caused an increased response time (P = 0.0230) and more omission errors (P = 0.0398). Diphenhydramine was also associated with increased drowsiness VAS ratings (P = 0.0065) compared with placebo. Diphenhydramine caused significantly more commission errors than fexofenadine (P = 0.0354). Neither placebonor fexofenadine 180 mg caused significant changes in any TOVA or VAS measurements compared with baseline. Fexofenadine was not statistically different from placebo for any evaluation.

CONCLUSIONS

The TOVA was sufficiently sensitive to differentiate between the central nervous system effects of fexofenadine and diphenhydramine. Fexofenadine 180 mg had no significant effect on the TOVA measures of performance or on self-reported drowsiness compared with placebo. In contrast, diphenhydramine 50 mg caused significant increases in omission errors and response time on the TOVA and increases in self-reported drowsiness compared with placebo [corrected].

Rhinasthma: a new specific QoL questionnaire for patients with rhinitis and asthma

INTRODUCTION

To date we have available specific instruments assessing health-related quality of life (HRQL) in rhinoconjunctivitis or in asthma, but not instruments evaluating rhinitis and asthma together, although they often coexist. The aim of our study was to develop and validate a specific quality of life (QoL) questionnaire for adult patients with rhinoconjunctivitis, asthma or both.

MATERIALS AND METHODS

A pool of 42 items covering the main symptoms and problems related to respiratory allergy, was generated based on literature review and clinical experience. The items were randomly listed and presented to 148 consecutive outpatients 46 suffering from asthma (age 32.9 +/- 14.3 years), 53 suffering from rhinoconjunctivitis (age 32.6 +/- 11.5 years) and 49 from asthma and rhinoconjunctivitis (age 35.6 +/- 12.2 years). The patients were asked to indicate which item they had directly experienced and for each of them, its importance on a four-point scale (1 = not important; 4 = very important). Twelve items were cancelled from the list, because of low importance or redundance. In the instrument validation phase, 104 patients (42 with rhinoconjunctivitis alone and 62 with asthma and rhinoconjunctivitis) were evaluated with the generic instrument SF-36 and the new questionnaire (RHINASTHMA).

RESULTS

RHINASTHMA was able to differentiate patients with rhinitis from those with both rhinitis and asthma. In stable condition, RHINASTHMA showed good reliability. The factor analysis extracted three factors with a good reliability (0.93, 0.87, 0.76).

DISCUSSION

RHINASTHMA is the first tool aimed at evaluating HRQL impairment in patients with rhinitis and/or asthma. It provides a short and simple assessment, and has overall psychometric properties. This is of relevance because of the frequent asthma-rhinitis comorbidity.

The health-related quality of life effects of once-daily cetirizine HCl in patients with seasonal allergic rhinitis: a randomized double-blind, placebo-controlled trial

BACKGROUND

Seasonal allergic rhinitis (SAR) is characterized by subjectively irritating symptoms that can have a substantial impact on the patient's health-related quality of life (HRQL), adversely affecting physical and social or work activity, interpersonal relationships, and general psychological well-being. The objective of this study was to test the effect of cetirizine HCl 10 mg once daily on the HRQL of adult patients 18-65 years of age with SAR, concurrently assessing safety and efficacy.

METHODS

Randomized double-blind, placebo-controlled, parallel group trial conducted during the 1999 spring SAR season at 19 centers in the US. Following a 1-week placebo run-in period, qualified patients were randomized to cetirizine 10 mg, or placebo once daily for a 2-week treatment period. Change in Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) and Total Symptom Severity Complex (TSSC) scores from baseline were the primary outcomes of interest.

RESULTS

Of the 611 patients enrolled, 403 (66%) were randomized. Cetirizine-treated patients reported significantly greater improvement in overall HRQL (P < 0.001) and in each of the seven domains of the RQLQ at all time-points (P < 0.05 to < 0.001) than the placebo group. They also experienced significantly greater symptom relief (P < 0.001) and were more satisfied with treatment (65% vs. 44%) compared to the placebo group. Correlations between symptomatic relief and overall HRQL improvement were moderate to strong and statistically significant (r = 0.49-0.68, P < 0.01).

CONCLUSIONS

Results of this study are consistent with previous investigations, suggesting cetirizine HCl 10 mg taken once daily in the morning offers symptomatic relief that improves the HRQL of adults suffering from SAR.

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.

Effects of fexofenadine and desloratadine on subjective and objective measures of nasal congestion in seasonal allergic rhinitis

BACKGROUND

In vitro studies have shown much higher H1-receptor antagonist potency with desloratadine (DL) compared to fexofenadine (FEX), although it is unclear whether this has any clinical relevance on disease control parameters in seasonal allergic rhinitis (SAR), especially for nasal congestion.

OBJECTIVE

To compare the relative efficacy between presently recommended doses of DL and FEX on daily measurements of peak nasal inspiratory flow (PNIF) and nasal symptoms in SAR.

METHODS

Forty-nine patients with SAR were randomized into a double-blind, placebo-controlled cross-over study during the grass pollen season, comparing 2 weeks of once daily treatment with (a) 180 mg FEX or (b) 5 mg DL, taken in the morning. There was a 7-10 day placebo run-in and washout prior to each randomized treatment. Measurements were made in the morning (AM) and in the evening (PM) for PNIF (the primary outcome variable), nasal and eye symptoms. The average of AM/PM values were used for analysis.

RESULTS

There were significant (P < 0.05) improvements, compared to placebo, with FEX and DL, for PNIF, nasal blockage, nasal irritation, and total nasal symptoms, but not nasal discharge or eye symptoms. There were no significant differences between active treatments. Values for PNIF (L/min) for mean placebo baseline, mean difference from baseline (95% CI for difference) were 126, 10 (4-16) for FEX; and 122, 11 (4-17) for DL. The mean difference (95% CI) between FEX vs. DL was 1 L/min (-7-8). Values for total nasal symptoms (out of 12) were: 3.2, 0.7 (0.2-1.2) for FEX; and 3.4, 0.9 (0.3-1.5) for DL, and for nasal blockage (out of 3) were: 1.1, 0.2 (0.1-0.4) for FEX; and 1.2, 0.3 (0.1-0.5) for DL. The mean difference (95% CI) in total nasal symptoms and nasal blockage between FEX vs. DL was 0.1 (-0.6-0.8) and 0.1 (-0.2-0.3), respectively.

CONCLUSIONS

Recommended once daily doses of fexofenadine and desloratadine were equally effective in improving nasal peak flow and nasal symptoms in SAR.

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.

A comparison of once daily fexofenadine versus the combination of montelukast plus loratadine on domiciliary nasal peak flow and symptoms in seasonal allergic rhinitis

BACKGROUND

The combination of montelukast (ML) and loratadine (LT) has previously been shown to be superior to either drug alone in managing seasonal allergic rhinitis (SAR), whilst fexofenadine (FEX) has been shown to be better than LT as monotherapy.

OBJECTIVES

We wished to compare ML + LT vs. FEX alone for effects on daily measurements (am/pm) of peak inspiratory flow (PIF) and symptoms.

METHODS

Thirty-seven patients with SAR (skin prick positive to grass pollen) were randomised into a single-blind, double-dummy placebo (PL)-controlled cross-over study during the grass pollen season, comparing 2 weeks of once daily treatment with (a) 120mg FEX or (b) 10mg ML + 10mg LT. There was a 7-10 day placebo run-in and washout prior to each randomised treatment. The average of am/pm PIF (the primary outcome variable) was analysed. Patients recorded their symptom scores (from 0 to 3) twice daily, for nasal blockage, discharge, itching and sneezing with; total eye symptoms, ocular cromoglycate use, and daily activity. The total nasal symptom score was calculated as a composite (out of 24).

RESULTS

There were no significant differences between baselines after the run-in and washout placebos for any variables. There were significant (P < 0.05, Bonferroni) improvements in all symptoms and PIF compared to pooled placebo with both treatments for all end-points, but no differences between the two treatment regimes (as means and within-treatment 95% confidence intervals): PIF: PL 102 (98-107), FEX 111 (107-116), ML+LT 113 (109-118); total nasal symptoms: PL 7.4 (6.7-2.0), FEX 5.0 (4.3-5.7), ML + LT 4.0 (3.3-4.7).

CONCLUSIONS

Once daily FEX as monotherapy was equally effective as the combination of once daily ML + LT in improving nasal peak flow and controlling symptoms in SAR. Further studies are indicated to assess whether ML confers additional benefits to FEX in SAR.

Allergic rhinitis and asthma in children: disease management and outcomes

Antihistamines and inhaled glucocorticoids, which can be targeted toward multiple points in the "allergic cascade" underlying allergic rhinitis and asthma, extend the promise of enhanced outcomes in children with allergic rhinitis, asthma, or both. Antihistamine therapy confers significant relief of subjective ratings of seasonal and perennial allergic symptoms (e.g., rhinorrhea, congestion, sneezing, pruritus), whereas topical steroids alleviate such discomfort while also improving objective anatomic and functional indices of nasal patency (e.g., nasal peak inspiratory flow). Youngsters with asthma also experience substantial clinical benefits from inhaled steroids, which improve objective measures of pulmonary function and reduce rescue beta 2-agonists for symptom management and quality-of-life enhancement. This paper reviews recent clinical findings on the role of antihistamines and topical corticosteroids in pediatric allergy and asthma management, as well as the favorable effects of these medications on both objective and subjective health outcomes.

Quality of life in adults and children with allergic rhinitis

Quality of life, when referring to an individual's health, is called health-related quality of life (HRQL). HRQL focuses on patients' perceptions of their disease and measures impairments that have significant impact on the patient. Similar symptoms may vary in their effect on different individuals; the goal of therapy should be to reduce impairments that patients consider important. HRQL can be measured with generic or specific questionnaires. Specific questionnaires may be more sensitive and are much more likely to detect clinically important changes in patients' impairments. Specific questionnaires used to assess HRQL in rhinitis are the Rhinoconjunctivitis Quality of Life Questionnaire, the Adolescent Rhinoconjunctivitis Quality of Life Questionnaire, and the Pediatric Rhinoconjunctivitis Quality of Life Questionnaire. HRQL issues in adult rhinitis patients include fatigue, decrease in energy, general health perception, and social function; impairment of HQRL generally increases with increasing degree of symptoms and severity of disease. In children, HRQL issues include learning impairment, inability to integrate with peers, anxiety, and family dysfunction. Comorbid disorders often associated with rhinitis, including sinusitis, otitis media, and frequent respiratory infections, can further compromise HRQL. Pharmacologic treatments can have both positive and negative effects on HRQL. Agents that have troublesome adverse effects such as sedation can have a negative impact, whereas nonsedating antihistamines and intranasal cortico-steroids can significantly improve HRQL in patients of all ages with rhinitis.

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.

Impact of allergic rhinitis treatment on quality of life

Allergic rhinitis is a chronic inflammatory disorder of the nasal passages. It affects approximately 20% of the population, is a significant health and economic burden, and severely impairs quality of life. Two main instruments, Medical Outcomes Study 36-Item Short Form health survey (SF-36) and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) have been used to assess quality of life in patients with allergic rhinitis. Antihistamines, corticosteroids, anticholinergic agents, decongestants, cromoglycates, and immunotherapy are used to treat patients with allergic rhinitis. Of these, antihistamines and intranasal corticosteroids are the most efficacious and frequently utilised medications. Studies have demonstrated improvements in quality of life with both of these medications in patients with allergic rhinitis.

Quality of life in patients with allergic rhinitis

LEARNING OBJECTIVES

Reading this article will familiarize the practitioner with ongoing efforts to measure the effects of allergic rhinitis symptoms and its treatments on the health-related quality of life (HRQOL) of patients. The reader will learn about instruments used to collect HRQOL data, results of studies showing the burden of illness and the effects of treatments on HRQOL, and efforts to interpret the clinical relevance of changes in HRQOL status.

DATA SOURCES

Information was gleaned from articles listed in MEDLINE regarding HRQOL in allergic rhinitis between 1966 and 2000 (English language only), and from the personal experiences of the authors.

STUDY SELECTION

Questionnaire validation studies and representative controlled trials employing measures to assess the effects of allergic rhinitis symptoms and its treatments on HRQOL are described. RESULTS FROM THIS REVIEW: Allergic rhinitis symptoms can have detrimental effects on the physical, psychologic, and social aspects of patients' lives. Clinical trial data suggest a variety of pharmacologic therapies can significantly improve HRQOL in patients with allergic rhinitis. Validated questionnaires are now available that can easily be used in clinical practice to measure the effects of interventions on HRQOL for individual patients.

CONCLUSIONS

Evaluating the effects of interventions on HRQOL may be particularly important in a non-life-threatening condition such as rhinitis. Health-related quality of life measures can be used to indicate the risk/benefit and the cost/benefit ratios of competing treatment options. Clinicians and policy makers are already using HRQOL data to evaluate results of medical interventions to guide patient management and reimbursement decisions.

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.

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.