Fluticasone propionate--an update on preclinical and clinical experience

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.

Safety and efficacy of fluticasone and beclomethasone in moderate to severe asthma. Belgian Multicenter Study Group

There are still some concerns about the safety of high doses of inhaled glucocorticosteroids (ICS). We compared the safety and efficacy of fluticasone propionate (FP) and beclomethasone dipropionate (BDP) in 306 patients with moderate to severe asthma in a double-blind, multicenter, cross-over study of 12 mo duration. During the 1-mo run-in period, bronchodilators were replaced by salmeterol 50 microg twice daily, increasing morning peak expiratory flow rate (PEFR) by 28 L/min (p < 0.001) and FEV1 by 6.2% predicted (p < 0.001). At randomization the current ICS was replaced by 500 microg BDP or 250 microg FP in accordance with previously taken 500 microg BDP or 400 microg budesonide (BUD). No significant differences between the two treatments regarding morning plasma cortisol, urinary excretion of calcium and hydroxyproline, FEV1, and PEFR were observed at any time point during the study. Osteocalcin and bone mineral density (BMD) were improved over baseline in the FP group, resulting in higher serum osteocalcin levels (mean difference 0.28 ng/ml; p < 0.001) and higher BMD in the spine (1.0%; p = 0.05), femoral neck (1.6; p < 0.01), and Ward's triangle (3.6%; p = 0.01) as compared with BDP. We conclude that chronic treatment with FP, at half the dose of BDP, results in a similar antiasthma effect but a more favorable safety profile with respect to bone metabolism and mineral density.

A sensitive method for the quantification of fluticasone propionate in human plasma by high-performance liquid chromatography/atmospheric pressure chemical ionisation mass spectrometry

A highly sensitive and selective method has been developed for the quantification of fluticasone propionate (FP) in human plasma. The drug was isolated from human plasma using C18 solid-phase extraction cartridges. The analysis was based on high-performance liquid chromatography/atmospheric pressure chemical ionisation mass spectrometry (HPLC/APCI/MS), using the 22R epimer of budesonide (BUD) acetate, synthesised using acetic anhydride, as internal standard. The mass spectrometer was operated in APCI mode with selected ions at tune masses of 473.2 and 501.2 m/z, corresponding to the MH+ of acetylated (22R)BUD and FP, respectively. The mobile phase used was a mixture of 50% ethanol in water with a flow rate of 0.45 ml min-1. The system was optimised by tuning the capillary and tube lens with a concentrated solution of FP. The recovery of FP from human plasma was 86.3%. Linearity of response was obtained over the concentration range 0.2-4.0 ng ml-1. The intra-assay and inter-assay variability were 6.3 and 2.9%, respectively. The lower limit of quantification was 0.2 ng ml-1 when a solid-phase extraction preceded the HPLC/APCI/MS.

RPR 106541, a novel, airways-selective glucocorticoid: effects against antigen-induced CD4+ T lymphocyte accumulation and cytokine gene expression in the Brown Norway rat lung

1. The effects of a novel 17-thiosteroid, RPR 106541, were investigated in a rat model of allergic airway inflammation. 2. In sensitized Brown Norway rats, challenge with inhaled antigen (ovalbumin) caused an influx of eosinophils and neutrophils into the lung tissue and airway lumen. In the lung tissue there was also an accumulation of CD4+ T lymphocytes and increased expression of mRNA for interleukin-4 (IL-4) and IL-5, but not interferon-gamma (IFN-gamma). These findings are consistent with an eosinophilia orchestrated by activated Th2-type cells. 3. RPR 106541 (10-300 microg kg[-1]), administered by intratracheal instillation into the airways 24 h and 1 h before antigen challenge, dose-dependently inhibited cell influx into the airway lumen. RPR 106541 (100 microg kg[-1]) caused a significant (P<0.01) (98%) inhibition of eosinophil influx and a significant (P<0.01) (100%) inhibition of neutrophil influx. RPR 106541 was approximately 7 times and 4 times more potent than budesonide and fluticasone propionate, respectively. 4. When tested at a single dose (300 microg kg[-1]), RPR 106541 and fluticasone each caused a significant (P<0.01) (100%) inhibition of CD4+ T cell accumulation in lung tissue. Budesonide (300 microg kg[-1]) had no significant effect. RPR 106541 and fluticasone (300 microg kg[-1]), but not budesonide (300 microg kg[-1]), significantly (P<0.05) inhibited the expression within lung tissue of mRNA for IL-4. RPR 106541 (300 microg kg[-1]) also significantly (P<0.05) inhibited expression of mRNA for IL-5. 5. The high topical potency of RPR 106541 in this model, which mimics important aspects of airway inflammation in human allergic asthmatics, suggests that this glucocorticoid may be useful in the treatment of bronchial asthma.

Fluticasone propionate powder administered through Diskhaler versus triamcinolone acetonide aerosol administered through metered-dose inhaler in patients with persistent asthma

BACKGROUND

Attempts to delineate efficacy and safety differences among inhaled corticosteroids have been difficult because of the lack of well-controlled, comparative studies reported in the medical literature.

METHODS

A randomized, double-blind, double-dummy study was conducted in 24 outpatient centers. A total of 291 male and female patients at least 12 years of age with asthma (FEV1 between 50% and 80% of predicted value), who had previously received maintenance therapy with beclomethasone dipropionate or triamcinolone acetonide, were switched to treatment with fluticasone propionate powder (250 microg twice daily), triamcinolone acetonide aerosol (200 microg four times daily), or placebo for 24 weeks.

RESULTS

Mean increase in FEV1 from baseline to end point was significantly (p = 0.009) greater in patients switched to treatment with fluticasone compared with patients switched to treatment with triamcinolone (0.27 L and 0.07 L, respectively). At end point, mean increase in morning peak expiratory flow from baseline was 21 L/min with fluticasone compared with mean decreases of 6 L/min and 28 L/min with triamcinolone and placebo, respectively (p < 0.001 vs triamcinolone and placebo). Supplemental rescue albuterol use decreased by 30% from baseline with fluticasone (p < 0.05 vs triamcinolone and placebo) compared with triamcinolone (6%) or placebo (increased by 50%). The percentage of patients withdrawn from the study because they met predefined lack-of-efficacy criteria was higher with placebo (60%) and triamcinolone (27%) than with fluticasone (17%). Incidence of adverse events and low morning plasma cortisol concentrations were similar across treatment groups except for oral candidiasis (p = 0.035, fluticasone vs placebo).

CONCLUSION

Fluticasone propionate powder twice daily (500 microg/day) was superior in efficacy to triamcinolone acetonide aerosol four times daily (800 microg/day) in patients with persistent asthma.

Dynamic modeling of cortisol reduction after inhaled administration of fluticasone propionate

Fluticasone propionate (FP) is a new corticosteroid that has been developed for the treatment of asthma. The compound has a very high receptor affinity, 18 times that of dexamethasone. After inhalation, FP is systemically available because of inhaled bioavailability. In healthy subjects this may lead to measurable systemic effects, such as cortisol reduction. A clinical study was conducted in 12 healthy volunteers to determine the systemic effects after inhaled administration of single 500-micrograms, 1,000-micrograms, and 2,000-micrograms doses of FP. Blood samples were collected over a 24-hour period after administration. Concentrations of FP and cortisol were measured in plasma by immunoassay. Cortisol reduction was chosen as the pharmacodynamic parameter. A novel linear release rate model was used to parameterize the cortisol data. The pharmacokinetics of FP were linear over the dose range studied. The cortisol release parameters were determined from baseline data (before drug administration). Based on these results, the E50 values for cortisol reduction were then determined for each dose of FP. The average E50 was 0.134 ng/mL for total FP concentrations and 0.013 ng/mL for unbound FP concentrations; these results were not dose dependent. These in vivo pharmacodynamic values measured in healthy subjects are in good agreement with the relatively high receptor affinity of FP.