Clinical pharmacology of corticosteroids in bronchial asthma

Insight into glucocorticoids glucosylation by glucosyltransferase: A combined experimental and in-silico approach

Glucosyltransferases catalyze the glucosidic bond formation by transferring a glucose molecule from an activated sugar donor to an acceptor substrate. Glucocorticoids (GCs) are adrenal-derived steroid hormones most widely used for anti-inflammatory treatments. In this study, we biotransformed two selected GCs, cortisone and prednisone, into their O-glucoside derivatives using a versatile UDP-glycosyltransferase UGT-1. Complete structural assignment of glucosylated products revealed that the bioconversion by regio-selective glucosylation of cortisone and prednisone produced cortisone 21-glucoside and prednisone 21-glucoside, respectively. We also combined molecular dynamics (MD) simulation to study the binding feature and mechanism of glucosylation. MD simulation studies showed the formation of a stable complex between protein, glucose donor, and substrate, stabilized by hydrogen bonds. Overall, we were able to provide explanations for the experimentally observed selectivity for glucosylation by integrating experimental and computational techniques.

Ginger-derived compounds exert in vivo and in vitro anti-asthmatic effects by inhibiting the T-helper 2 cell-mediated allergic response

6-Shogaol (SHO) and 6-gingerol (GIN), naturally derived compounds of ginger (Zingiber officinale Roscoe), have been found to have anti-allergic effects on dermatitis-like skin lesions and rhinitis. Although SHO and GIN have demonstrated a potential in various inflammatory diseases, their efficacy and mechanism in asthma have not been largely examined. Therefore, the present study demonstrated the anti-asthmatic effects of SHO and GIN on the T-helper (Th) 2 cell-mediated allergic response pathway in an ovalbumin (OVA)-induced asthma mouse model. The asthma mouse model was established with an intraperitoneal (i.p.) injection of 50 µg OVA and 1 mg aluminum hydroxide with or without an i.p. injection of SHO and GIN (10 mg/kg) before treatment with OVA. In addition, the current study assessed mast cell degranulation in antigen-stimulated RBL-2H3 cells under different treatment conditions (SHO or GIN at 0, 10, 25, 50 and 100 nM) and determined the mRNA and protein levels of anti-oxidative enzymes [superoxide dismutase (SOD)1, SOD2, glutathione peroxidase-1/2, catalase] in lung tissues. SHO and GIN inhibited eosinophilia in the bronchoalveolar lavage fluids and H&E-stained lung tissues. Both factors also decreased mucus production in periodic acid-Schiff-stained lung tissues and the levels of Th2 cytokines in these tissues. GIN attenuated oxidative stress by upregulating the expression levels of anti-oxidative proteins. In an in vitro experiment, the degranulation of RBL-2H3 rat mast cells was significantly decreased. It was found that SHO and GIN effectively suppressed the allergic response in the mouse model by inhibiting eosinophilia and Th2 cytokine production. Collectively, it was suggested that SHO can inhibit lung inflammation by attenuating the Th2 cell-mediated allergic response signals, and that GIN can inhibit lung inflammation and epithelial cell remodeling by repressing oxidative stress. Therefore, SHO and GIN could be used therapeutically for allergic and eosinophilic asthma.

What makes flunisolide different among inhaled corticosteroids used for nebulization: a close look at the role of aqueous solubility

Evidence-based management of bronchial asthma and wheezing in children and adults recommends the employment of inhaled corticosteroids (ICSs). Difficulty in using some inhalation devices for ICS delivery, such as pressurized metered-dose and dry-powder inhalers, is common among young children and in the elderly, and for that reason, they are replaced with nebulizers. We reviewed comparative studies that evaluated funisolide with other ICSs currently available on the market, including beclomethasone dipropionate, fluticasone propionate, and budesonide. Moreover, we assessed the physicochemical properties of these ICSs in determining drug fate in the lung. Data indicate that the flunisolide output in respirable particles by any type of pneumatic nebulizer (traditional, open breath or breathenhanced) is superior to the output of other ICSs. This is principally attributed to the higher water solubility of flunisolide. Furthermore, in vivo simulation studies demonstrate that the intersubject variability of the inhaled dose among asthmatic children was much greater for suspensions of fluticasone propionate and beclomethasone dipropionate than for those of flunisolide. The physicochemical properties and pharmacokinetic profile of flunisolide favor its employment in nebulization.

Pharmacodynamic and pharmacokinetic assessment of fluticasone furoate + vilanterol for the treatment of asthma

INTRODUCTION

The pharmacokinetic (PK) and pharmacodynamic (PD) effects of long-acting β2-agonists and mostly inhaled corticosteroids (ICSs) shape the efficacy and safety of these agents in the treatment of asthma. In fact, the PK and PD characteristics of the drug largely determine the degree of pulmonary targeting Areas covered. In this review, we summarize the PK and PD properties of inhaled fluticasone furoate (FF) and vilanterol trifenatate (VI) and their fixed-dose combination (FDC) for the treatment of asthma Expert opinion. It is difficult to interpret the data that we have described because the preclinical and clinical development of FF/VI FDC was not really based on solid information on quantitative PK/PD approach. Unfortunately, for both FF and VI we only know concentrations in systemic blood, a compartment that is downstream of both target and non-target respiratory tissue. This lack of information does not allow us to understand the temporal relationship between the delivered dose and the drug concentration at the sites of action within the lungs. In addition, all studies performed with FF and VI did not address the fundamental issue that asthma can significantly alter lung deposition, absorption and also clearance of inhaled medicines.

Absence of gargling affects topical adverse symptoms caused by inhaled corticosteroids in females

OBJECTIVE

Topical adverse events caused by inhaled corticosteroids (ICS) are suspected to be more common in females. Although gargling or mouth washing after inhalation is recommended as the gold standard for preventing adverse events due to ICS, the preventive effects of this method have not been confirmed in real-world studies. This study aimed to examine the association between gargling or mouth washing and the incidence of topical adverse symptoms in males and females in daily practice.

METHODS

We analyzed a subpopulation of participants in the Drug Event Monitoring (DEM) project of the Japan Pharmaceutical Association. An anonymous survey was performed in February 2010, to assess the self-perception of topical adverse symptoms during ICS use by conducting interviews of pharmacists using structured questionnaires.

RESULTS

A total of 412 males and 480 females were included. The patients used a dry-powder inhaler (DPI) (71.2%), pressurized meter-dose inhaler (pMDI) with (7.5%) or without (16.6%) a spacer or inhalation solution (4.7%) as the delivery device. Topical adverse symptoms occurring after previous prescriptions were reported by 41 (4.6%) subjects. The common symptoms were hoarseness, stomatitis and dry mouth (1.3%, 1.1% and 1.1%, respectively). In the multiple regression model, the presence of symptoms was found to be significantly associated with the absence of gargling or mouth washing after inhalation [adjusted odds ratio (OR): 3.75, 95% confidence interval (95%CI): 1.33-10.59, p = 0.012]. When stratified by gender, the absence of gargling or mouth washing was identified to be a risk factor in females only (OR: 4.32, 95%CI: 1.11-16.87, p = 0.035) and not in males (OR: 3.26, 95%CI: 0.65-16.33, p = 0.151). Furthermore, the association between the absence of gargling or mouth washing and the incidence of topical adverse symptoms was significant in the patients using DPI (OR: 4.85, 95%CI: 1.66-14.14, p = 0.004), but not in those using the other devices.

CONCLUSIONS

In this study, the absence of gargling or mouth washing after ICS use was associated with topical adverse symptoms, especially in females. To achieve good adherence to treatment and improve the quality of life, female patients with asthma should strictly practice the gargling or mouth washing method.

Montelukast versus inhaled corticosteroids in the management of pediatric mild persistent asthma

International guidelines recommend the use of inhaled corticosteroids (ICSs) as the preferred therapy, with leukotriene receptor antagonists (LTRAs) as an alternative, for the management of persistent asthma in children. Montelukast (MLK) is the first LTRA approved by the Food and Drug Administration for the use in young asthmatic children.Therefore, we performed an analysis of studies that compared the efficacy of MLK versus ICSs. We considered eligible for the inclusion randomized, controlled trials on pediatric populations with Jadad score > 3, with at least 4 weeks of treatment with MLK compared with ICS.Although it is important to recognize that ICSs use is currently the recommended first-line treatment for asthmatic children, MLK can have consistent benefits in controlling asthmatic symptoms and may be an alternative in children unable to use ICSs or suffering from poor growth. On the contrary, low pulmonary function and/or high allergic inflammatory markers require the corticosteroid use.

Impact of inhaled corticosteroid-induced oropharyngeal adverse events: results from a meta-analysis

BACKGROUND

Oropharyngeal adverse events associated with inhaled corticosteroid (ICS) use can affect adherence; however, these effects have been studied less extensively than those that occur systemically.

OBJECTIVE

To calculate the risk of ICS-induced oral candidiasis, dysphonia, and pharyngitis among currently available therapies and to determine related effects of dose and device.

METHODS

A computerized search in MEDLINE (January 1966 to June 2004) and EMBASE (January 1974 to June 2004) was conducted using indexed MedDRA terms for oropharyngeal adverse events. Odds ratios (ORs) were used to determine the rate of ICS-induced adverse events based on dose and device.

RESULTS

A total of 23 studies (59 drug arms) were evaluated. Incidence of oral candidiasis (P < or = .001), dysphonia (P < or = .001), and pharyngitis (P < or = .023) increased significantly with dose vs placebo at all dose levels and combined, regardless of device. Overall, the ICS metered-dose inhaler (MDI) device (hydrofluoroalkane formulation, 4 arms; chlorofluorocarbon formulation, 26 arms) was associated with a 5-fold greater risk of oral candidiasis vs MDI placebo (OR, 5.40). In contrast, the ICS dry-powder inhaler (DPI) device had a 3-fold greater risk for oral candidiasis vs DPI placebo (OR, 3.24). A similar trend was observed with regard to dysphonia (ICS MDI: OR, 5.68; ICS DPI: OR, 3.74; both vs. placebo). Both ICS MDI and DPI were associated with an approximately 2-fold greater risk of pharyngitis compared with placebo.

CONCLUSIONS

Currently available inhaled corticosteroids canbe associated with oropharyngeal adverse events. Such events may be reduced by postdose mouth rinsing or use of a spacer.

A novel murine model of pharyngeal candidiasis with local symptoms characteristic of pharyngeal thrush produced by using an inhaled corticosteroid

We established a novel murine model of pharyngeal candidiasis maintaining stable yeast population and local symptoms characteristic of pharyngeal thrush. The persistent Candida-infection was prolonged by inhalation of beclomethasone dipropionate corticosteroid. The severity of infection lesions was evaluated by determining viable cell number of Candia albicans and scores representing symptomatic curd-like white patch on pharyngeal tissue. The utility of this model was shown by the disappearance of lesions and fungal cells after treatment with fluconazole (FLCZ). The model would be useful for evaluating new chemotherapeutic or immunotherapeutic approaches against pharyngeal candidiasis, as well as in pathological studies.

A randomized open-label comparative study of montelukast versus theophylline added to inhaled corticosteroid in asthmatic children

BACKGROUND

Inhaled corticosteroids (ICSs) are widely used in combination with other classes of drugs for treatment of childhood asthma. The efficacy and the safety of montelukast added to low-dose ICS therapy were compared with those of sustained-release theophylline added to low-dose ICS therapy in asthmatic children in the present study.

METHODS

Following the 2-week run-in period, 6-to 14-year old patients receiving treatment with ICSs were randomized to treatment for 4 weeks with either montelukast 5 mg once daily or sustained release theophylline 5-8 mg/kg (dry syrup) or 100-200 mg (tablet) twice daily. Patients also received a fixed dose of ICS throughout the run-in and treatment periods. The primary efficacy endpoint was the change from baseline in peak expiratory flow (PEF) at Week 2.

RESULTS

A significant increase in morning PEF was observed in the add-on montelukast group as compared with the add-on theophylline group at Week 2 (change from baseline of 22.8 L/minvs. 8.7 L/min; p = 0.041 for between-group difference) and at Week 4 (31.0 L/minvs. 9.8 L/min; p = 0.012). A significant increase in evening PEF was observed in the add-on montelukast group as compared with the add-on theophylline group at Week 4 (24.7 L/minvs. 8.7 L/min; p = 0.027). There were no significant differences between the treatment groups in incidences of clinical and laboratory adverse experiences.

CONCLUSIONS

The results indicate that montelukast added to low-dose ICS is an effective and safe option for the treatment of asthma in children.

Inhaled beclomethasone versus placebo for chronic asthma

BACKGROUND

Inhaled beclomethasone dipropionate (BDP) has been, together with inhaled budesonide, the mainstay of anti-inflammatory therapy for asthma for many years. A range of new prophylactic therapies for asthma is becoming available and BDP has been reformulated using a hydrofluoroalkane-134a (HFA) propellant which is free from chlorofluorocarbon (CFC).

OBJECTIVES

The objectives of this review were to: (1) Compare the efficacy of BDP with placebo with both CFC and HFA propellants in the treatment of chronic asthma. (2) Explore the possibility that a dose response relationship exists for BDP in the treatment of chronic asthma. (3) To provide the best estimate of the efficacy of BDP as a benchmark for evaluation of newer asthma therapies.

SEARCH STRATEGY

Electronic searches were current as of January 2003.

SELECTION CRITERIA

Randomised parallel group design trials for a minimum period of four weeks, in children and adults comparing CFC-BDP or HFA-BDP with placebo in the treatment of chronic asthma. Two reviewers independently assessed articles for inclusion and methodological quality.

DATA COLLECTION AND ANALYSIS

One reviewer extracted data; authors were contacted to clarify missing information. We analysed data with RevMan Analyses 1.0.2.

MAIN RESULTS

60 studies recruiting 6542 participants met the inclusion criteria. CFC-BDP (57 studies): In non-oral steroid treated patients, at doses of 400 mcg/day or less CFC-BDP produced significant improvements from baseline in a number of efficacy measures compared with placebo, including forced expiratory volume in one second (FEV1) 360 ml (95% CI 260 to 460); FEV1 (% predicted) WMD 12.41% (95% CI 8.18 to 16.64) and morning peak expiratory flow rate (am PEF) WMD 35.95 L/min (95% CI 27.85 to 44.04). BDP also led to reductions in rescue beta-2 agonist use compared with placebo of -2.32 puffs/d (95% CI -2.55 to -2.09) and reduced the relative risk (RR) of trial withdrawal due to an asthma exacerbation 0.25 (95% CI 0.12 to 0.51). Subgroup analyses based on treatment duration provide support to the proposal that a treatment period of greater than four weeks is required to realise a fuller treatment effect. In oral steroid treated patients BDP led to significantly greater reductions in oral prednisolone use WMD -4.91 mg/d (95% CI -5.88 to -3.94 mg/d) and greater likelihood of withdrawing oral steroid treatment RR 8.02 (95% CI 3.23 to 19.92). HFA-BDP (3 studies): In non-oral steroid-treated patients, HFA-BDP was significantly more effective than placebo in improving FEV1, morning and evening PEF, FEF25 to 75%, reduced asthma symptoms and beta2-agonists daily consumption. Significant effects for such outcomes were apparent after six weeks of treatment. In oral steroid treated patients, HFA-BDP improved significantly FEV1 and am PEF. The summary estimates for these outcomes suggested a high level of heterogeneity, and divergent aims of the studies may contribute to the variation we observed. Limited data on adverse events were reported.

AUTHORS' CONCLUSIONS

This review has quantified the efficacy of CFC-BDP and HFA-BDP in the treatment of chronic asthma and strongly supports its use. Current asthma guidelines recommend titration of dose to individual patient response, but the published data provide little support for dose titration above 400 mcg/d in patients with mild to moderate asthma. There are insufficient data to draw any conclusions concerning dose-response in people with severe asthma.

Skin manifestations of inhaled corticosteroids in COPD patients: results from Lung Health Study II

OBJECTIVE

To define the relationship between skin bruising (as well as other cutaneous manifestations) and inhaled corticosteroid (ICS) therapy vs placebo in subjects with COPD who were participating in a clinical trial. To explore the relationship between easy skin bruising and other systemic effects of ICS therapy, including adrenal suppression and loss of bone mineral density (BMD).

DESIGN

Double-blind, randomized, placebo-controlled clinical trial of triamcinolone acetonide (1200 microg daily) vs placebo in participants with mild-to-moderate COPD.

SETTING

Lung Health Study II, a clinical trial to assess the effect of ICS compared to placebo in 1,116 participants in 10 centers over > 3.5 to 4.5 years.

PARTICIPANTS

A total of 1,116 smokers or recent ex-smokers with mild-to-moderate COPD (age range, 40 to 69 years; mean age, 56.3 years; 37.2% female).

MEASUREMENTS AND RESULTS

Every 6 months, a structured questionnaire was administered to elicit reports of any bruising and/or skin rashes, slow healing of cuts or sores, or other skin changes. Compliance with inhaler use was assessed by canister weighing. A significantly higher proportion of ICS than placebo participants who complied with using their inhaler reported easy bruising (11.2% vs 3.5%, respectively) and the slow healing of skin cuts or sores (2.4% vs 0.5%, respectively). Older men in the ICS group with good inhaler compliance appeared to be at the greatest risk of bruising. In those participants undergoing serial measurements of adrenal function and BMD, no association was noted between skin bruising and either the suppression of adrenal function or the loss of BMD as systemic complications of ICS use.

CONCLUSION

These findings indicate that moderate-to-high doses of ICSs result in an increased incidence of easy bruising and impairment in skin healing in middle-aged to elderly persons with COPD. No association was noted between skin bruising and other markers of systemic toxicity from the use of ICSs.

Prevalence of esophageal candidiasis among patients treated with inhaled fluticasone propionate

OBJECTIVES

Development of oropharyngeal candidiasis is a frequently reported adverse effect of inhaled corticosteroid use, but the prevalence of esophageal candidiasis is unknown. The aim of this study was to estimate the prevalence of esophageal candidiasis among patients treated with an inhaled corticosteroid, fluticasone propionate.

METHODS

Upper GI endoscopy was performed on 49 patients treated with inhaled fluticasone propionate to examine the prevalence of esophageal candidiasis. Of the patients, 36 had bronchial asthma and 13 had chronic obstructive pulmonary disease. To compare the prevalence with control patients, upper GI endoscopy was performed on 700 consecutive patients without malignancy or immunosuppression.

RESULTS

The prevalence of esophageal candidiasis was 37% among patients treated with inhaled fluticasone propionate, whereas only 0.3% of the control patients had the infection. The prevalence was especially high among patients with diabetes mellitus or those who were treated with a high dose of inhaled fluticasone propionate. Moreover, a reduction in the daily dose of inhaled fluticasone propionate eliminated the infection in four of five patients.

CONCLUSIONS

Esophageal candidiasis is a common complication of inhaled corticosteroid use.

Oral candidiasis associated with inhaled corticosteroid use: comparison of fluticasone and beclomethasone

BACKGROUND

Inhaled steroids such as fluticasone propionate and beclomethasone dipropionate play a central role in the treatment of bronchial asthma. Fluticasone exhibits excellent clinical effectiveness; however, oral adverse effects can occur.

OBJECTIVE

To compare the frequency of oral candidiasis in asthmatic patients treated with fluticasone and beclomethasone, to evaluate the effect of gargling with amphotericin B, and to measure the inhalation flow rate on candidiasis.

METHODS

The study consisted of 143 asthmatic patients who were treated with inhaled steroids, 11 asthmatic patients not treated with inhaled steroids, and 86 healthy volunteers. Quantitative fungal culture was performed by aseptically obtaining a retropharyngeal wall swab from these patients. Patients with positive results were treated with gargling using a 1:50 dilution amphotericin B solution. In asthmatic patients treated with fluticasone, the inhalation flow rate was measured using an inspiratory flow meter.

RESULTS

The amount of Candida spp. was significantly greater in asthmatic patients taking inhaled steroids compared with those who were not. It was also significantly greater in patients with oral symptoms than asymptomatic patients and significantly greater in asthmatic patients treated with fluticasone than in those treated with beclomethasone. Although the presence of Candida did not correlate with the inhaled dose of beclomethasone, it did increase with the dose of fluticasone. Gargling with amphotericin B was effective in most asthmatic patients with candidiasis. Candidiasis was not due to inappropriate flow rates during inhalation of steroids.

CONCLUSIONS

Fungal culture of a retropharyngeal wall swab may be useful for predicting the risk of developing oral candidiasis in asthmatic patients treated with inhaled steroids. The amount of isolated Candida was significantly greater in asthmatic patients treated with fluticasone than in those treated with beclomethasone. Attention to dosage is required as the amount of Candida increased with dose of fluticasone. Gargling with a 1:50 dilution of amphotericin B is effective in treating oral candidiasis of asthmatic patients treated with inhaled steroids.

Effects of amphotericin B gargles on oral colonization of Candida albicans in asthmatic patients on steroid inhalation therapy

BACKGROUND

Early use of inhaled steroids is recommended for bronchial asthma. The side effects are rare, but oral discomfort and candidiasis are clinically important complications. Most previous studies reported that the use of spacer and water gargling was necessary to prevent oral complications. However, in some patients, this may fail to prevent such complications.

OBJECTIVE

To compare the effects of water gargling with those of amphotericin B, in the prevention of oral complications in asthmatics using inhaled steroids.

METHODS

Pharyngeal swab samples were obtained aseptically from the posterior pharyngeal wall of 128 asthmatics who have been using inhaled steroids (beclomethasone dipropionate) for more than 1 year. The amount of Candida albicans in cultured swabs was evaluated based on the following criteria: oral symptoms, method of gargling, dose of inhaled steroids, type of spacer and serum cortisol level.

RESULTS

The number of isolated C. albicans was significantly higher in asthmatics with oral symptoms than in those free of symptoms. It was also significantly higher in patients who gargled with water or 1,000 times dilution than in those who gargled with 100 or 50 times dilutions of amphotericin B. Moreover, it was significantly higher in patients with low levels of serum cortisol than in those with normal serum cortisol.

CONCLUSION

We demonstrated that at least in a subgroup of asthmatics using steroid inhalers, gargling with water or even weak concentrations of amphotericin B does not prevent colonization of the throat with C. albicans. This group at high risk of developing oral candidiasis should gargle with amphotericin B at concentrations higher than 100 times dilution that can prevent clinically detectable oral candidiasis.

Asthma stability after oral prednisone: a clinical model for comparing inhaled steroid potency

Clinical studies comparing the potency of inhaled corticosteroids require steep dose-response slopes (b) and minimal response variability (s), as statistical power is inversely related to the s/b ratio. To evaluate a new study model, we performed a randomized, crossover study of 12 adult asthmatics who required 800 to 2,000 microg of inhaled corticosteroids daily, and calculated s/b for 21 raw clinical outcomes and 36 mathematically derived variables based on these raw outcomes. Each of two 21-d treatment periods was preceded by 4 to 7 d of oral prednisone to maximize asthma control and minimize carry-over of previous inhaled treatment. Treatments were 100 and 800 micron/d of an HFA-134a beclomethasone dipropionate formulation. Assessments included daily home spirometry, histamine challenge, inhaled albuterol use, and asthma symptom scores. Efficacy variables with the greatest power (lowest s/b values) were A.M.FEF25-75, A.M.FEV1, and A.M.PEF, (s/b = 0.46, 0.48, and 0.59). Carry-over between treatment periods was not significant. Crossover study sample size calculations using these ratios yielded samples of 23, 25, and 37 patients, respectively. Otherwise identical parallel studies would require sample sizes of 657, 1,438, and 2,261 patients. These results support the use of a crossover asthma stability model after a short course of oral prednisone as a clinical study model for comparing topical potency of inhaled corticosteroids.

History and future perspectives of treating asthma as a systemic and small airways disease

Asthma is an inflammatory disorder in which the small airways of the lung play an important role. There is also evidence for the systemic nature of asthma. No current method adequately measures small airways function alone. Therefore, a combination of functional and clinical parameters should be used to ensure that patients with asthma are adequately treated with due consideration of the small airways. Previously therapeutic strategies have focused on bronchodilation and attenuation of airway inflammation. While early oral therapies had the advantage of reaching the small airways and treating the systemic aspect of asthma, they were associated with serious side-effects. Inhaled therapies were therefore developed to limit these effects. However, inhaled therapies have the disadvantage of limited penetration into the peripheral airways and an inability to treat the systemic component of asthma. They are also associated with local and systemic side-effects. The future for asthma treatment is likely to be a systemically administered medication with few side-effects targeting disease-specific mediators. The leukotriene receptor antagonists and anti-IgE monoclonal antibodies are examples of such therapies and the emergence of other new strategies is awaited.

Drugs for the treatment of allergic diseases

Many kinds of drugs are used for the treatment of allergic diseases. Glucocorticoids are the most efficacious drugs and widely used for the treatment of allergic diseases. Recently, effectiveness of inhaled glucocorticoids for the treatment of bronchial asthma has been established. Beclomethasone dipropionate and fluticasone propionate, which are degraded easily after absorption, are applied by inhalation. Histamine is one of the most important mediators in allergic reactions and antihistamines have widely been applied for the treatment of allergic skin diseases. In Japan, over 20 antiallergic drugs, such as mediator release inhibitors, mediator antagonists and mediator synthesis inhibitors, have been developed. Recently developed compounds such as pranlukast and suplatast are very effective. To relieve the asthmatic attack, bronchodilators such as beta2-adrenoceptor agonists, theophylline and anti-cholinergic drugs are used. Clinical application of tacrolimus ointment has just started for the treatment of atopic dermatitis. Recently the number of allergic patients has increased. The onset and development of allergic diseases are considered to be dependent on both the genetic factors and the environmental factors. For the successful treatment of patients with allergic diseases, it is also important to consider the control of environmental factors.

Efficacy and safety overview of a new inhaled corticosteroid, QVAR (hydrofluoroalkane-beclomethasone extrafine inhalation aerosol), in asthma

Chlorofluorocarbon (CFC)-containing inhalers are gradually being phased out and replaced with hydrofluoroalkane (HFA)-based alternatives. The reformulation provided the opportunity to improve the inhalation technology and physical characteristics of corticosteroid formulations. QVAR contains HFA-beclomethasone dipropionate (HFA-BDP) with the steroid in solution rather than suspension, which, in combination with improved inhaler technology, produces an extrafine aerosol with a mass median aerodynamic diameter of 1.1 microm (smaller than the 3.5-4.0 microm found with CFC-BDP). It was predicted and demonstrated that the smaller particle size of QVAR would be deposited in the lung to a greater extent than that found with CFC-BDP, particularly in the small airway, a major site of inflammation. Increased lung deposition of QVAR permits a reduction in dosage relative to CFC-BDP. Clinical evidence confirms that adult and elderly patients required approximately half the dose of QVAR to achieve the same degree of asthma control as with CFC-BDP. In long-term assessments, patients taking CFC-BDP could be switched to QVAR at half the daily dose without exacerbation of their asthma symptoms. QVAR was associated with a low overall incidence of side effects and, at the maximum recommended dose of 640 microg/d, caused no more adrenal suppression than 672 microg/d CFC-BDP.

Dysphonia associated with inhaled steroids

The use of inhaled steroids in the treatment of asthma is not without its complications. In some studies up to 50% of such patients complain of oropharyngeal and voice problems. We present the findings in 22 patients complaining of dysphonia who underwent videostrobolaryngoscopy (VSL) and computerized speech analysis. A number of abnormalities were identified. On VSL, these included mucosal changes (noted in 58%), apposition abnormalities (noted in 43%), and supraglottic hyperfunction (noted in 40%). On speech analysis, cycle-to-cycle irregularity was frequently noted (mean of 39%). Maximum phonation time was reduced in 73%. Our findings did not confirm the widely held views that steroid dysphonia is due primarily to a fungal infection or a steroid-induced adductor myasthenia of the larynx. A larger-scale prospective study is indicated.

A double-blind, placebo-controlled dose-response study with budesonide Turbuhaler in Japanese asthma patients. Japanese Pulmicort Turbuhaler study group

OBJECTIVE

The aim of this study was to investigate the dose-response for inhaled budesonide via Turbuhaler in Japanese patients with mild to moderate asthma.

METHODOLOGY

Inhaled budesonide 100 microg, 200 microg, 400 microg or placebo was administered twice daily via Turbuhaler for 6 weeks, to 267 adult Japanese patients (mean age 51 years) with mild-to-moderate, non-steroid-dependent bronchial asthma, in a double-blind, placebo-controlled, randomized, parallel group study. The patients had to be symptomatic for more than 3 days/week and have an average morning peak expiratory flow (PEF) 50-80% of predicted normal value.

RESULTS

The response to budesonide was rapid, all treatments showing a significant improvement in morning PEF after 1 week (P<0.05). During week 6, mean improvements of 15, 45, 53 and 71 L/min were observed for the placebo, 200 microg, 400 microg and 800 microg budesonide groups, respectively. Compared with placebo all improvements in the budesonide groups were statistically significant and a significant dose-response was demonstrated (P<0.001). The difference between the 200 microg and 800 microg doses was significant. Also, for several secondary efficacy variables (e.g. evening PEF, symptom score, treatment score, daily activity score and sleep score) significant dose-responses were shown. Other variables included the investigators' assessments of improvement and usefulness. They also showed statistically significant dose-response relationships and confirmed the rapid onset of action. Budesonide was well tolerated at all tested doses, with a low incidence of adverse events, all of which were minor in severity.

CONCLUSIONS

Budesonide Turbuhaler in the doses 100 microg to 400 microg twice daily was effective, well tolerated and showed a rapid onset of action in patients with mild-to-moderate asthma. Dose-response was demonstrated for several variables of clinical efficacy.

Effectiveness of low doses (50 and 100 microg b.i.d) of beclomethasone dipropionate delivered as a CFC-free extrafine aerosol in adults with mild to moderate asthma. Study Group

The objective of this study was to evaluate the efficacy and safety of low doses (50 and 100 microg b.i.d.) of hydrofluoroalkane-134a (HFA) beclomethasone dipropionate (BDP) extrafine aerosol in improving asthma control. Reformulation of BDP in a new chlorofluorocarbon (CFC)-free propellant (HFA) has produced an extrafine aerosol with increased delivery of the drug to the airways of the lung. The study population comprised 270 steroid-naive patients with mild to moderate asthma (mean baseline forced expiratory volume in 1 sec [FEV1] as a percentage of predicted normal of 65%-85%). This was a 6-week, blinded, placebo-controlled, multicenter study. Patients were randomized to receive 50 or 100 microg b.i.d. HFA-BDP or HFA-placebo. Treatment with either 50 or 100 microg b.i.d. HFA-BDP resulted in a significantly greater improvement compared with placebo in FEV1 (mean change from baseline as percentage of predicted normal of 6.7%, 8.6%, and 0.4%, respectively; p < or = 0.01 active treatment groups vs. placebo), with a significant trend toward increasing improvement with increasing doses (p < or = 0.0001). Treatment also resulted in significantly greater mean changes from baseline in morning peak expiratory flow compared with placebo (29.5, 33.8, and 5.0 L/min, respectively; p < or = 0.01 active treatment groups vs. placebo). All other pulmonary function and asthma symptom measures supported these data. The study treatments were well tolerated. These results show that low doses of HFA-BDP extrafine aerosol effectively improve asthma control in adult patients with mild to moderate asthma. However, it is important that inhaled corticosteroid therapy is still given at a dose high enough to control airway inflammation as well as asthma symptoms.

Montelukast or salmeterol combined with an inhaled steroid in adult asthma: design and rationale of a randomized, double-blind comparative study (the IMPACT Investigation of Montelukast as a Partner Agent for Complementary Therapy-trial)

Asthma patients who continue to experience symptoms despite taking regular inhaled corticosteroids represent a management challenge. Leukotrienes play a key role in asthma pathophysiology, and since pro-inflammatory leukotrienes are poorly suppressed by corticosteroids it seems rational to add a leukotriene receptor antagonist (LTRA) when a low to moderate dose of inhaled corticosteroids does not provide sufficient disease control. Long acting beta2-agonist (LABA) treatment represents an alternative to LTRAs and both treatment modalities have been shown to provide additional disease control when added to corticosteroid treatment. To compare the relative clinical benefits of adding either a LTRA or a LABA to asthma patients inadequately controlled by inhaled corticosteroids, a randomized, double-blind, multi-centre, 48-week study will be initiated at approximately 120 centres throughout Europe, Latin America, Middle East, Africa and the Asia-Pacific region in early 2000. The study will compare the oral LTRA montelukast with the inhaled LABA salmeterol, each administered on a background of inhaled fluticasone, on asthma attacks, quality of life, lung function, eosinophil levels, healthcare utilization, and safety, in approximately 1200 adult asthmatic patients. The requirements for study enrollment include a history of asthma, FEV1 or PEFR values between 50% and 90% of the predicted value together with > or = 12% improvement in FEV1 after beta-agonist administration, a minimum pre-determined level of asthma symptoms and daily beta-agonist medication. The study will include a 4-week run-in period, during which patients previously taking inhaled corticosteroids are switched to open-label fluticasone (200 microg daily), followed by a 48-week double-blind, treatment period in which patients continuing to experience abnormal pulmonary function and daytime symptoms are randomized to receive montelukast (10 mg once daily) and salmeterol placebo, or inhaled salmeterol (100 microg daily) and montelukast placebo. All patients will continue with inhaled fluticasone (200 microg daily). During the study, asthma attacks, overnight asthma symptoms, and morning peak expiratory flow rate will be assessed using patient diary cards; quality of life will also be assessed using an asthma-specific quality-of life questionnaire. The results of this study are expected to provide physicians with important clinical evidence to help them make a rational and logical treatment choice for asthmatic patients experiencing breakthrough symptoms on inhaled corticosteroids.

Phosphodiesterase 4 inhibitors, structurally unrelated to rolipram, as promising agents for the treatment of asthma and other pathologies

An increase of cyclic adenosine and guanosine monophosphate (cAMP and cGMP) level can be achieved by inhibition of phosphodiesterases (PDEs), which are the enzymes responsible for the conversion of these second messengers into the corresponding 5-monophosphate inactive counterparts. The high heterogeneity in PDE families and in their tissue distribution, as well as their different functional role, make these enzymes very attractive targets for medicinal chemists. The PDE 4 family is particularly abundant in immunocompetent cells, where an increase of cAMP leads to the inhibition of the synthesis and release of pro-inflammatory mediators, cytokines and active oxygen species. Moreover PDE 4 inhibitors are able to reduce bronchial smooth muscle tone in vitro and show bronchodilatory effects in vivo. Thus, the current therapy for asthma, which is based on a combination of beta(2) agonists and corticosteroids, could be replaced by treatment with PDE 4 inhibitors. This review mainly covers PDE 4 inhibitors structurally related to xanthines and Nitraquazone, which appear to be very attractive models for the synthesis of novel PDE 4 inhibitors potentially useful for the treatment of asthma, chronic pulmonary obstructive disease and some autoimmune diseases. These compounds could be devoid of the central side-effects (nausea, vomiting, headache) of the archetypal Rolipram, which hampered its development as a drug. The review also highlights the novel structural classes of PDE 4 inhibitors recently reported in the literature.

Health-related quality of life in moderate asthma: 400 microg hydrofluoroalkane beclomethasone dipropionate vs 800 microg chlorofluorocarbon beclomethasone dipropionate. The Study Group

OBJECTIVE

To compare the effect of hydrofluoroalkane-134a (HFA) beclomethasone dipropionate (BDP; 400 microg/d) with that of chlorofluorocarbon (CFC) BDP (800 microg/d) on asthma health-related quality of life in a 12-week, parallel-group, multicenter study.

BACKGROUND

HFA-BDP is a new CFC-free preparation of BDP, which was developed as a result of CFCs being phased out from metered dose inhalers.

METHODS

Following 7 to 12 days of prednisone, 30 mg/d, 347 adults with moderate asthma were randomized to receive either 400 microg/d HFA-BDP, 800 microg/d CFC-BDP, or HFA placebo for 12 weeks (all other oral and inhaled steroids were withdrawn). Patients completed the Asthma Quality of Life Questionnaire (AQLQ), and clinical asthma status was measured at the end of a run-in period, at randomization (after oral steroid treatment), and at the end of the study treatment.

RESULTS

Sixty-one patients withdrew, 43 due to worsening asthma (33 placebo; 5 HFA-BDP; 5 CFC-BDP). There was a deterioration in the AQLQ score (- 0.81) in the placebo group, and the difference between this and the stability observed in both the HFA-BDP group (+ 0.13) and the CFC-BDP group (- 0.03) was statistically significant (p </= 0.003). The difference between the two active treatments was not significant (p = 0.290). The calculated number of patients who needed to be treated in order to see a benefit in one patient (with the placebo as the standard treatment) was 2.4 for HFA-BDP and 3.0 for CFC-BDP. Only weak to moderate correlations were observed between changes in AQLQ scores and between asthma clinical status measures.

CONCLUSION

HFA-BDP (400 microg/d) was as effective as CFC-BDP (800 microg/d) in sustaining improvements in asthma quality of life following withdrawal of 7 to 12 days of prednisone treatment in moderate asthma.

Inhaled corticosteroids for adult asthma: impact of formulation and delivery device on relative pharmacokinetics, efficacy and safety

Metered dose inhalers (MDIs) are the mainstay of inhaled steroid therapy for asthma. With the phasing out of traditional chlorofluorocarbon (CFC) propellants and their replacement with a new generation of CFC-free products, it is becoming clear that formulation and inhaler characteristics can markedly affect the drug delivery. It now seems necessary to compare inhalers not only on the basis of the properties of the steroid molecules but also to take into account the effect of propellants and other inhaler characteristics. The impact of formulation and delivery device on relative pharmacokinetics, therapeutic efficacy and tolerability is illustrated by a new preparation of beclomethasone dipropionate (BDP) in an inhaler containing hydrofluoroalkane (HFA) propellant, called Qvar (3M Health Care, U.K.). This drug preparation delivers the majority of particles (60%) in the fine particle range. This appears to be associated with improved lung deposition, a halving of dose requirements of BDP, but no evidence of clinically relevant adrenal suppression when used in therapeutic doses. Prescribers need to be aware of the impact of formulation on pharmacokinetics of inhaled steroids in order to offer the lowest effective dose and give clear instructions to patients who are changing to a CFC-free product.

Effects of dexamethasone on airway hyper-responsiveness to the adenosine A1 receptor agonist cyclo-pentyl adenosine in an allergic rabbit model

1. New Zealand White (NZW) rabbits were immunized within 24 h of birth with Alternaria tenuis in aluminium hydroxide (Al (OH)3) (i.p.) or sham immunized (saline plus Al (OH)3 i.p.) and subsequently injected with the allergen (i.p.) or sham-immunized for the next 3 months. At 3 months of age, baseline airway responsiveness was assessed using cyclo-pentyl adenosine (CPA). Bronchoalveolar lavage (BAL) was performed in all animals and samples of peripheral blood were collected from some animals for estimation of dexamethasone levels. In some animals, blood was collected at the end of the experiment and cellular function was assessed by measurement of ex vivo proliferation of mononuclear cells in response to phytohaemagglutinin (PHA). 2. Allergen immunization significantly increased baseline airway responsiveness to inhaled CPA (P<0.05) in comparison with sham-immunized animals, at 3 months after immunization. Dexamethasone (0.5 mg kg(-1) day(-1)) treatment for 1 month did not modify this established airway hyper-responsiveness to CPA. Dexamethasone treatment did not affect either total or differential cell numbers in BAL fluid during the 4 week period, although significant plasma levels of dexamethasone were achieved in dexamethasone treated animals. 3. Treatment of rabbits with dexamethasone (0.1 mg kg(-1) i.p.), 6 h prior to each allergen injection from the neonatal stage, significantly reduced baseline airway hyper-responsiveness to CPA measured at 3 months (P<0.05). There was no significant difference in either total or differential cell numbers in BAL fluid, or any difference in mitogen-induced proliferation of mononuclear cells between dexamethasone and vehicle treated rabbits. 4. These results suggest that introduction of glucocorticosteroids in early life can prevent baseline airway hyper-responsiveness to inhaled CPA in allergic rabbits. However, once established, such underlying airway hyper-responsiveness is difficult to resolve, even with prolonged treatment with glucocorticosteroids.

Hydrofluoroalkane-134a beclomethasone dipropionate, 400 microg, is as effective as chlorofluorocarbon beclomethasone dipropionate, 800 microg, for the treatment of moderate asthma

OBJECTIVE

The improved lung deposition of hydrofluoroalkane-134a beclomethasone dipropionate (HFA-BDP) extrafine aerosol compared with chlorofluorocarbon beclomethasone dipropionate (CFC-BDP) suggests that lower doses of HFA-BDP may be required to provide equivalent asthma control. The present study was undertaken to test this hypothesis.

DESIGN

A 10- to 12-day run-in period confirmed that patients met established criteria of at least moderate asthma and the asthma was inadequately controlled by current therapy (inhaled beta-agonist and CFC-BDP [< or = 400 microg/d]). A short course of oral prednisone, 30 mg/d for 7 to 12 days, was followed to establish the patients were steroid responsive and to provide an "in-study" baseline of "optimal" asthma control.

PATIENTS

A total of 347 patients were then randomized to HFA-BDP 400 microg/d, CFC-BDP 800 microg/d, or HFA-placebo for 12 weeks.

RESULTS

Morning peak expiratory flow (AM PEF) measurements showed that HFA-BDP 400 microg/d achieved equivalent control of asthma to CFC-BDP 800 microg/d at all time intervals after oral steroid treatment. All other efficacy variables supported the AM PEF results and both active treatments were more effective than placebo. The safety profile of HFA-BDP compared favorably with that of CFC-BDP with no unexpected adverse events reported.

CONCLUSIONS

These findings demonstrate that HFA-BDP provides equivalent control of moderate or moderately severe asthma as CFC-BDP in the population studied, but at half the total daily dose.

The effect of intranasal and inhaled corticosteroids in healthy volunteers on the number of circulating lymphocytes and lymphocyte subsets

BACKGROUND

There has been an increasing interest in the potential systemic effects of inhaled corticosteroids.

METHODS

The effect of locally inhaled corticosteroids in the nose and lung on blood lymphocytes was measured in two studies. In the first study, budesonide (BUD) (200 and 800 microg), fluticasone propionate (FP) (200 and 800 microg), and placebo were administered in the nose, and BUD (1600 microg) and FP (1500 microg) were inhaled into the lungs in a blinded, randomized fashion by 12 healthy volunteers. Blood samples were taken before and 4 h after the administration of the drug, and total lymphocyte count and different subpopulations were determined. In the second study, 15 healthy volunteers were randomized to BUD (1600 microg), FP (1600 microg), or placebo inhaled into the lungs. Blood samples were taken before and 4, 8, 24, 48, and 148 h (=7 days) after inhalation of the medication.

RESULTS

Neither the nasal applications nor the inhalation of FP (1500 microg/1600 microg) showed significant differences in total lymphocyte count or different subpopulations between baseline and 4 h after the administration. In both studies, a significant reduction was found in the total lymphocyte count, B cells, T cells, and the CD4+ and the CD8+ fractions 4 h after application of BUD 1600 microg.

CONCLUSIONS

Nasal application of BUD or FP in doses up to 800 microg do not induce lymphopenia. BUD 1600 microg inhalation in the lung reduces lymphocytes and their subfractions. Further studies have to be done to determine whether the results obtained in this study in healthy volunteers will also be found in patients with diseased mucosa and whether there is any correlation with adverse effects such as growth inhibition or osteoporosis.

Asthma-related prescribing patterns with four different corticosteroid inhaler devices

Four types of corticosteroid inhaler devices are available in New Zealand for first-line treatment of asthma, including two aerosol systems [Autohaler (3M Healthcare Ltd, Loughborough, U.K.; 3M Pharmaceuticals (Australia Pty Ltd, Sydney, Australia) and MDI (Glaxo Wellcome PLC, Ware, U.K.)] and two dry powder systems [Diskhaler (Glaxo Wellcome) and Turbuhaler (Astra AB, Sodertalje, Sweden)]. Rates of asthma-related health care consumption and treatment outcomes associated with use of the different inhalers are unknown. In this retrospective survey, asthma-related primary health care consultation and prescription patterns were compared in a large general practice population for each corticosteroid inhaler device prescribed as first-line treatment. An electronic search of a computerized clinical database yielded the medical records of 5704 patients with physician-diagnosed asthma who were prescribed either the Autohaler, Diskhaler, MDI or Turbuhaler as their sole corticosteroid inhaler device in the previous 12 months. The mean daily inhaled corticosteroid dose was lowest for the Autohaler (569 micrograms day-1; 95% CI: 538-605), followed by the Diskhlaer (638 micrograms day-1; 95% CI: 609-670) and MDI (665 micrograms day-1; 95% CI: 638-673), and was highest for the Turbuhaler (990 micrograms day-1; 95% CI: 954-1029, P < 0.001). A relatively high proportion of patients aged 19-49 years in the Turbuhaler and Diskhaler groups (29% and 23%, respectively) received at least one inhaled corticosteroid prescription including a daily dose greater than 1500 micrograms compared with the MDI group (4%). In the Diskhaler group the mean daily inhaled corticosteroid dose prescribed for adult patients was similar to that for the Turbuhaler group (904 micrograms day-1 and 1058 micrograms day-1, respectively). These data suggest that in New Zealand the dry powder corticosteroid inhaler devices are prescribed for adults at significantly higher doses than the aerosol inhaler devices. Clinical databases of this type yield valuable information on drug utilization in large patient populations and usefully assess clinical prescribing practices.

Comparison of potency of inhaled beclomethasone and budesonide in New Zealand: retrospective study of computerised general practice records

OBJECTIVE

To determine whether inhaled budesonide and beclomethasone are equipotent in the treatment of asthma in primary care.

DESIGN

Retrospective study of computerised clinical records from 28 general practices in New Zealand.

SUBJECTS

5930 patients who received 16 725 prescriptions for inhaled budesonide or beclomethasone from 1 July 1994 to 30 June 1995.

SETTING

General practices on the database of the Royal New Zealand College of General Practitioners Research Unit. Linked information from secondary care was available for a subset of the practices.

MAIN OUTCOME MEASURE

Mean prescribed daily inhaled corticosteroid dose.

RESULTS

The daily prescribed dose was higher for patients receiving inhaled budesonide (mean 979 microg) than beclomethasone (mean 635 microg), a difference of 344 microg (95% confidence interval 313 to 376 microg). This difference was consistent in all age bands and with different types of inhalation device. Evidence of systematic prescribing of higher doses of budesonide to patients with more severe asthma was not found.

CONCLUSIONS

In primary care in New Zealand evidence suggests that budesonide is less potent than beclomethasone. Consideration of validated, established, and other possible markers of asthma severity did not support confounding by severity as a reason for the higher prescribed doses of budesonide. Pending further epidemiological evaluation, international asthma guidelines may need to be modified on the equivalence of inhaled corticosteroid doses. Furthermore, the comparative potency of newly developed inhaled steroids in clinical trials will need to be confirmed in appropriately designed epidemiological studies based in general practice.

Safety of hydrofluoroalkane-134a beclomethasone dipropionate extrafine aerosol

Herein we assess the safety of an inhaled formulation of beclomethasone dipropionate (BDP) which uses the propellant hydrofluoroalkane-134a (HFA) for the treatment of asthma. Acute local tolerability (as assessed by the incidence of cough and mean forced expiratory volume after 1 s inhalation) was similar for both BDP and placebo formulated in either chlorofluorocarbon (CFC) or HFA propellants. A total of 43 patients were treated with HFA-BDP (0, 200, 400 or 800 micrograms day-1) or CFC-BDP (800 micrograms day-1) for 14 days and their 24 h urinary free cortisol (UFC) excretion and response to cosyntropin stimulation were measured. There was no difference in UFC between any of the doses of HFA-BDP and CFC-BDP. Adrenal responsiveness to cosyntropin stimulation was normal in all but one patient. Two large 12 week phase III trials compared HFA-placebo, HFA-BDP 400 micrograms day-1 and CFC-BDP 800 micrograms day-1 (n = 347), and HFA-BDP 800 micrograms day-1 and CFC-BDP 1500 micrograms day-1 (n = 233). For HFA-BDP at either dose, CFC-BDP 800 micrograms day-1 and HFA-placebo, the number of patients with morning plasma cortisol concentrations below normal was less than 4.4% but was 14.6% for CFC-BDP 1500 micrograms day-1. The incidence of adverse events was lower in the HFA-BDP groups than in the CFC-BDP groups (P = 0.012). The data indicate that, at doses of up to 800 micrograms day-1, HFA-BDP is at least as well tolerated as CFC-BDP. Other studies have found that equivalent efficacy is reached at lower doses of HFA-BDP than CFC-BDP. Equivalent efficacy at a lower dose and equivalent safety at the same dose imply that HFA-BDP may have a more favourable risk: benefit ratio than CFC-BDP when used at the recommended lower doses.

Hydrofluoroalkane-134a beclomethasone dipropionate extrafine aerosol provides equivalent asthma control to chlorofluorocarbon beclomethasone dipropionate at approximately half the total daily dose

The mandatory requirement to eliminate chlorofluorocarbons (CFCs) as propellants in pharmaceutical aerosols has provided the opportunity to enhance significantly the delivery of aerosol drugs to the respiratory tract. This randomized, parallel-group, double-blind, double-dummy, multicentre study was undertaken to assess whether beclomethasone dipropionate (BDP) in hydrofluoroalkane-134a (HFA) provided equivalent control of moderately severe asthma to BDP in CFC but at approximately half the total daily dose, as might be expected from the improved lung deposition of the HFA-BDP extrafine aerosol. The novel study design included a 10-12 day run-in period to confirm that patients met established criteria of moderately severe asthma and were symptomatic on current therapy (inhaled beta-agonist plus CFC-BDP 400-800 micrograms day-1). This run-in period was followed by a short course of oral steroid therapy (prednisolone 30 mg day-1 for 7-13 days) to demonstrate steroid responsiveness [> or = 15% improvement in morning peak expiratory flow (PEF)] and to provide a within-study baseline of improved asthma control. A total of 233 patients were randomized to treatment for 12 weeks with HFA-BDP 800 micrograms day-1 (116 patients) or CFC-BDP 1500 micrograms day-1 (117 patients). The mean change from oral steroid treatment in morning PEF with HFA-BDP was equivalent to that seen with CFC-BDP at all time intervals. Changes in other measures of pulmonary function, asthma symptom scores and beta-agonist use were equivalent in the two treatment groups throughout the 12 week treatment period. The safety profile of HFA-BDP compared favourably with that of CFC-BDP with no unexpected adverse events reported. Fewer patients on HFA-BDP than on CFC-BDP had plasma cortisol levels below the normal reference range after 12 weeks of therapy (5.1% vs. 17.3%, respectively). In conclusion, HFA-BDP extrafine aerosol was found to provide equivalent control of moderately severe asthma to CFC-BDP at approximately half the daily dose with a favourable safety profile, suggesting an improved therapeutic ratio.

Aerosol therapy in the equine species

Inhalation therapy plays an increasing role in the management of equine respiratory disorders. This alternative to systematic treatment permits a high concentration of medication to act locally while minimizing side effects and residues. In human medicine, literature in this field is prolific and continuously renewed, whereas in veterinary medicine, applications of aerosol therapy are less extensive. This review considers the principles of action of the different types of devices used for inhalation, i.e., nebulization, metered-dose inhalation and dry powder inhalation, describes the technical and practical requirements for their use in the equine species and considers the advantages and disadvantages of each inhalation device. The pharmacological agents currently administered to horses by inhalation are also discussed. Perspectives of aerosol therapy in the equine species, including aerosols already used in human medicine and their potential applications for horses are described.

Central serous chorioretinopathy associated with inhaled or intranasal corticosteroids

OBJECTIVE

The purpose of the study is to investigate the relationship between inhaled or intranasal adrenergic agonists and corticosteroids and the development of central serous chorioretinopathy (CSC).

DESIGN

The medical records of three patients with CSC who were found to use inhaled adrenergic agents or corticosteroids or both were identified prospectively. A survey of members of the Retina, Macula, and Vitreous societies and the National Registry of Drug-Induced Ocular Side Effects identified three additional cases.

RESULTS

Six patients with CSC were found to be chronic users of corticosteroid (four patients) or both beta adrenergic agonist and corticosteroid (two patients) metered dose inhalers or nasal sprays. In three cases, there was a close temporal correlation between the use of a corticosteroid nasal spray and the development of CSC.

CONCLUSIONS

These findings suggest that, in patients who are susceptible, the periocular or systemic absorption of inhaled corticosteroids may be sufficient to produce CSC in humans, supporting previous hypotheses regarding the pathogenesis of the disorder. Further studies are needed to confirm this association and to determine whether inhaled adrenergic agents also contribute to the development of this disorder. Patients in whom CSC develops while using corticosteroid inhalers or nasal sprays should be alerted to the possible relationship between CSC and these agents.

Novel heterocyclic-fused pyridazinones as potent and selective phosphodiesterase IV inhibitors

A series of 6-aryl-4,5-heterocyclic-fused pyridazinones were designed and synthesized as selective phosphodiesterase (PDE) IV inhibitors. Biological evaluation of these compounds demonstrated a good selectivity profile toward the PDE IV family and greatly attenuated affinity for the Rolipram high-affinity binding site that seems to be responsible for undesiderable side effects. Structure-activity relationships (SARs) studies showed that the presence of an ethyl group at pyridazine N-2 is associated with the best potency and selectivity profile.

Dose-response of inhaled drugs in asthma. An update

The demographic characteristics of patients used in clinical trials (such as the severity of airway obstruction) can significantly influence the results of dose-response studies, emphasising the need to evaluate effects on the steep part of the dose-response curve. Differences in inhaler devices can also influence study outcomes, as for inhaled drugs both airway efficacy and adverse effect profiles are primarily determined by lung deposition and hence bioavailability. Dose-response studies with short- and long-acting beta 2-agonists show an excellent therapeutic ratio at conventional doses used in everyday clinical practice (i.e. 2 to 4 puffs). Dose-related systemic effects of beta 2-agonist occur at higher doses, for salbutamol (albuterol) > 500 micrograms. Fenoterol is a beta 2-agonists with higher intrinsic activity than salbutamol and produces greater systemic effects at higher than conventional doses on a microgram equivalent basis, although even at 4000 micrograms such differences are unlikely to be clinically relevant. No differences between fenoterol and salbutamol have been shown in terms of bronchodilator potency on a microgram equivalent basis. The long-acting beta 2-agonist salmeterol, as a partial agonist, has the potential to attenuate the acute bronchodilator response to a higher activity beta 2-agonist such as salbutamol or fenoterol, although there is no evidence to date on whether this is relevant in the setting of acute asthma. When comparing inhaled corticosteroids, attention should be focused on their respective risk-benefit ratios for antiasthmatic versus systemic activity. In terms of detecting systemic activity, it is important to use sensitive measures, such as urinary cortisol excretion, rather than insensitive parameters, such as a single morning plasma cortisol measurement between 0800h and 1000h. For fluticasone, a greater in vitro potency results in only marginal differences in antiasthmatic efficacy, particularly on the flatter part of the dose-response curve above 1000 micrograms/day in adults and 400 micrograms/day in children. However, the same enhanced potency translates directly into commensurate differences in systemic adverse effects on the steep part of the systemic dose-response curve above 1000 micrograms/day in adults and 400 micrograms/day in children, respectively. Furthermore, with repeated twice-daily administration, a longer elimination half-life and prolonged systemic tissue retention due to enhanced lipophilicity will result in greater systemic activity observed at steady-state in long term administration studies. This dissociation of airway and systemic dose-response curves results in a J-shaped curve for benefit: risk ratio, with a watershed area above 1000 microgram/day in adults. This fall in the benefit: risk ratio is likely to be greater for fluticasone than for budesonide or beclomethasone. Further studies are needed to clearly define the dose-response relationships of higher potency steroids such as fluticasone, particularly on the steep part of the curve (for clinical efficacy), using the appropriate back-titration design along with sensitive measures of antiasthmatic and systemic activity.

Inhibition of PAF-, LPS-, and cytokine-induced granulocyte accumulation in guinea pig lung by dexamethasone: evidence that inhibition of IL-5 release is responsible for the selective inhibition of eosinophilia by glucocorticoids in guinea-pigs

The potency of dexamethasone has been determined as an inhibitor of intratracheally administered platelet activating factor- (PAF), or interleukin (IL)-5-induced eosinophilia, and of lipopolysaccharide-(LPS), tumour necrosis factor alpha-(TNF alpha) or cytokine-induced neutrophil chemoattractant- (CINC) induced neutrophilia in guinea-pig lungs. Dexamethasone was a potent inhibitor of PAF- induced eosinophil accumulation, but higher doses of dexamethasone were required to inhibit IL-5-induced eosinophilia. LPS-induced neutrophilia was less sensitive to the inhibitory effects of dexamethasone, than PAF-induced eosinophilia. Both LPS- and TNF alpha-induced neutrophilia were inhibited by the same doses of dexamethasone. In contrast, higher doses of dexamethasone were required to inhibit CINC-induced neutrophilia. Since data in the literature show that PAF-induced eosinophilia in guinea-pig lungs is dependent on the generation of IL-5, it is concluded that inhibition of this response, by dexamethasone, is due to inhibition of release of IL-5. Similarly, although data in the literature show that LPS-induced neutrophilia is dependent on the generation of TNF alpha, it is concluded that inhibition of this response, by glucocorticoids, is due to an action on an event which occurs after the release of TNF alpha, possibly through inhibition of chemokine release.

Comparative adrenal suppression with inhaled budesonide and fluticasone propionate in adult asthmatic patients

BACKGROUND

A study was performed to compare the adrenal suppression caused by inhaled fluticasone propionate and budesonide on a microgram equivalent basis, each given by metered dose inhaler to asthmatic patients.

METHODS

Twelve asthmatic patients of mean age 29.9 years, with a forced expiratory volume in one second (FEV1) 92.9% predicted and forced expiratory flow 25-75% (FEF25-75) 69.5% predicted, on less than or equal to 400 micrograms/day inhaled corticosteroid, were studied in a double blind placebo controlled crossover design comparing single doses of inhaled budesonide 400, 1000, 1600, 2000 micrograms and fluticasone propionate 500, 1000, 1500, 2000 micrograms. Doses were administered at 22.00 hours by metered dose inhaler with mouth rinsing and measurements were made in the laboratory 10 hours later.

RESULTS

Serum cortisol levels compared with placebo (mean 325.2 nmol/l) were suppressed by fluticasone at doses of 1500 micrograms (211.6 nmol/l) and 2000 micrograms (112.3 nmol/l) and by budesonide at 2000 micrograms (243.4 nmol/l). Fluticasone propionate 2000 micrograms produced lower absolute serum cortisol levels than budesonide 2000 micrograms (95% CI for difference 42.9 to 219.2). The dose ratio (geometric mean) for the relative potency was 2.89 fold (95% CI 1.19 to 7.07). In terms of percentage suppression versus placebo, fluticasone propionate also produced greater effects (means and 95% CI for difference): budesonide 1600 micrograms (16.0) versus fluticasone propionate 1500 micrograms (40.9) (95% CI -0.6 to 50.6), budesonide 2000 micrograms (26.0) versus fluticasone 2000 micrograms (65.2) (95% CI 10.5 to 67.8). Individual serum cortisol levels at the two highest doses showed 15 of 24 patients below the normal limit of the reference range (150 nmol/l) for fluticasone and five of 24 for budesonide. Fluticasone propionate also caused greater ACTH suppression than budesonide (as % versus placebo): budesonide 1600 micrograms (12.0) versus fluticasone propionate 1500 micrograms (31.9) (95% CI 7.6 to 32.1), budesonide 2000 micrograms (13.5) versus fluticasone propionate 2000 micrograms (44.4) (95% CI 13.2 to 48.7). For overnight 10 hour urinary cortisol (nmol/10 hours) there was a difference between the lowest doses of the two drugs: budesonide 400 micrograms (37.2) versus fluticasone propionate 500 micrograms (19.9) (95% CI 6.9 to 27.8).

CONCLUSIONS

Like budesonide the systemic bioactivity of fluticasone propionate is mainly due to lung vascular absorption. Fluticasone propionate exhibited at least twofold greater adrenal suppression than budesonide on a microgram equivalent basis in asthmatic patients.

Inhibition of some aspects of acute inflammation of guinea-pig lung by intraperitoneal dexamethasone and mifepristone: demonstration of agonist activity of mifepristone in the guinea-pig

We have determined the inhibitory activity of dexamethasone as an inhibitor of histamine-induced plasma protein extravasation (PPE) in guinea-pig lung and skin, and of lipopolysaccharide (LPS)-induced neutrophilia and platelet activating factor (PAF)-induced eosinophilia in guinea-pig lungs. Dexamethasone inhibited PAF-induced eosinophilia in guinea-pig lung (ED50 1.4 mg/kg i.p.). Higher doses of dexamethasone were required to inhibit LPS-induced neutrophilia (ED50 10.8 mg/kg i.p.). However, at doses up to 150 mg/kg i.p. dexamethasone did not inhibit histamine-induced plasma protein extravasation (PPE) in guinea-pig lung, but did inhibit PPE in guinea-pig skin. These preparations have previously been shown to be equally sensitive to inhibition by the beta 2-adrenoceptor agonist salmeterol. Dexamethasone inhibited PAF-induced eosinophilia (5 mg/kg) or LPS-induced neutrophilia (50 mg/kg) when given 3 h or 1 h prior to challenge. Inhibitory activity was lost when dexamethasone was administered 23 h prior to LPS or 1 h after PAF. The glucocorticoid antagonist mifepristone (1-100 mg/kg i.p.) caused dose-related inhibition of PAF-induced eosinophilia but not of LPS-induced neutrophilia. The highest dose of mifepristone used (100 mg/kg) did not reverse the inhibitory actions of dexamethasone (50 mg/kg) on LPS-induced neutrophilia. We suggest that the different inhibitory activity of dexamethasone in the preparations studied indicates differences in the sensitivity of the target cells involved to inhibition by dexamethasone. We also suggest that inhibition of PAF-induced eosinophilia by mifepristone reflects the partial agonist activity of this agent, demonstrated by others in different experimental systems.

Clinical efficacy of budesonide Turbuhaler compared with that of beclomethasone dipropionate pMDI with volumatic spacer. A 2-year randomized study in 102 asthma patients

A total of 102 patients had their asthma treatment with beclomethasone dipropionate (BDP) optimized in order to achieve the best possible control of symptoms. Thereafter, the BDP doses were gradually reduced over a 2-year period (1988-90) to the lowest possible without deterioration of their asthmatic condition. In the beginning of 1990, treatment was changed in 76 patients (group A) to the nearest possible dose of budesonide delivered via Turbuhaler. Twenty-six randomly selected patients (25% of the study population; group B) continued treatment with BDP. In both groups, dose reductions were tried during 1990-2 every third month as long as the patients remained symptom-free and without significant decreases in FEV1 or PEF. In group A, the maintenance dose could be reduced from 1003.9 +/- 325.4 micrograms BDP (mean +/- SD) to 602.9 +/- 454.4 micrograms budesonide Turbuhaler (P < 0.001). In group B, no significant dose reduction was possible; the mean dose was +/- SD 1067.3 +/- 36.6 micrograms in 1990, and 1019.2 +/- 324.7 micrograms in 1992. The results indicate that, in efficacy, 0.6 mg budesonide Turbuhaler corresponds to approximately 1.0 mg BDP with volumatic spacer. This difference is probably due to an improved pulmonary delivery of budesonide with Turbuhaler.

A comparison of the systemic bioactivity of inhaled budesonide and fluticasone propionate in normal subjects

1. The aim of this study was to compare the systemic bioactivity of low and high doses of inhaled budesonide and fluticasone propionate given by respective dry powder inhaler devices. 2. A randomised, single blind cross-over design was used in nine healthy subjects who were given 800 micrograms day-1 of budesonide Turbohaler (B800) for 1 week, followed by 1 week of 1600 micrograms day-1 (B1600), or fluticasone Diskhaler 750 micrograms day-1 (F750) for 1 week followed by 1 week of 1500 micrograms day-1 (F1500). There was a 1 week washout between treatments with fluticasone or budesonide. A twice daily dosing regime was used and mouth-rinsing was employed to reduce gut bioavailability as well as to obviate local adverse effects. 3. Parameters of hypothalmic-pituitary adrenal (HPA) axis activity and bone metabolism were measured at baseline (B0/F0), at the end of each week of treatment and after the 1 week washout (F0 or B0). 4. Both fluticasone and budesonide significantly (P < 0.05) attenuated the post tetracosactrin serum cortisol at low and high doses whilst early morning cortisol was unchanged. No dose-response effect was observed with either drug, and there was no significant difference between treatment with fluticasone or budesonide. 5. Neither budesonide nor fluticasone produced significant suppression of plasma osteocalcin, although the higher doses of both drugs significantly reduced fasting urinary calcium levels.(ABSTRACT TRUNCATED AT 250 WORDS)