Evaluation of the effect of a large volume spacer on the systemic bioactivity of fluticasone propionate metered-dose inhaler

A Pilot Study of the Normative Range of Overnight Urinary Free Cortisol Corrected for Creatinine in Children

BACKGROUND

For more than a decade, urinary free cortisol corrected for creatinine (OUFCC) has been used to assess the systemic bioactivity of inhaled corticosteroids in children with asthma. Paediatric normative ranges, however, have not been established. The aim of the present study was to define a preliminary range for OUFCC in Tanner stage 1 children.

METHODS

A post hoc analysis was performed of 26 Tanner stage one children (aged 5-11 years) with mild asthma only requiring prn (pro re nata) treatment with short-acting β₂-agonists, who participated in a 3-way cross-over knemometry study. The study comprised a run-in, two washout periods and three treatment periods (2 weeks each). Urine was collected at the end of each period. A normative range was derived using the 95% prediction interval for the geometric mean OUFCC, calculated from run-in and washout periods.

RESULTS

Twenty-six children contributed 41 OUFCC values. The geometric mean OUFCC was 9.0 nmol/mmol (95% PI: 3.6, 22.7 nmol/mmol).

CONCLUSIONS

The OUFCC preliminary normative range was 3.6 to 22.7 nmol/mmol in Tanner stage one children. A larger study in healthy children is warranted to confirm these findings and to assess potential differences in OUFCC across developmental stages and age groups, and by gender and race.

EUDRACT NUMBER

2013-004719-32, CLINICALTRIALS.

GOV IDENTIFIER

NCT02063139.

Spacer devices for inhaled therapy: why use them, and how?

We present an extensive review of the literature to date pertaining to the rationale for using a spacer/valved holding chamber (VHC) to deliver inhaled therapy from a pressurised, metered-dose inhaler, a discussion of how the properties of individual devices may vary according to their physical characteristics and materials of manufacture, the potential risks and benefits of ancillaries such as valves, and the evidence that they contribute tangibly to the delivery of therapy. We also reiterate practical recommendations for the correct usage and maintenance of spacers/VHCs, which we trust offer practical help and advice to patients and healthcare professionals alike.

[A new fixed dose combination of fluticasone and formoterol in a pressurised metered-dose inhaler for the treatment of asthma]

The combination of an inhaled corticosteroid and a long acting beta-2 agonist is indicated for the regular treatment of persistent moderate-to-severe asthmatics whose asthma is not controlled by inhaled corticosteroids and the occasional use of a short acting beta-2 agonist. The aim of this review is to give an overview of the rationale of combining formoterol and fluticasone and to analyze the clinical data concerning a new fixed combination of fluticasone and formoterol in a pressurised metered-dose inhaler with a dose counter (Flutiform(®)) that was approved for the treatment of asthma in France in 2013. The clinical studies provide evidence that combined fluticasone/formoterol is more efficacious than fluticasone or formoterol given alone, and provides similar improvements in lung function to fluticasone (Flixotide(®)) and formoterol (Foradil(®)) administered concurrently. The combination of fluticasone/formoterol gave a more rapid bronchodilatation than the combination fluticasone/salmeterol. As a whole, the combination of fluticasone/formoterol had similar efficacy and tolerability profiles to the combinations of either budesonide/formoterol or fluticasone/salmeterol.

Effect of AeroChamber Plus™ on the lung and systemic bioavailability of beclometasone dipropionate/formoterol pMDI

AIM

To assess the effect of AeroChamber Plus™ on lung deposition and systemic exposure to extra-fine beclometasone dipropionate (BDP)/formoterol (100/6 µg) pMDI (Foster®). The lung deposition of the components of the combination given with the pMDI was also evaluated using the charcoal block technique.

METHODS

Twelve healthy male volunteers received four inhalations of extra-fine BDP/formoterol (100/6 µg) using (i) pMDI alone, (ii) pMDI and AeroChamber Plus™ and (iii) pMDI and charcoal ingestion.

RESULTS

Compared with pMDI alone, use of AeroChamber Plus™ increased the peak plasma concentrations (C(max)) of BDP (2822.3 ± 1449.9 vs. 5454.9 ± 3197.1 pg ml(-1)), its active metabolite beclometasone 17-monopropionate (17-BMP) (771.6 ± 288.7 vs. 1138.9 ± 495.6 pg ml(-1)) and formoterol (38.4 ± 17.8 vs. 54.7 ± 20.0 pg ml(-1)). For 17-BMP and formoterol, the AUC(0,30 min), indicative of lung deposition, was increased in the AeroChamber Plus™ group by 41% and 45%, respectively. This increase was mainly observed in subjects with inadequate inhalation technique. However, use of AeroChamber Plus™ did not increase the total systemic exposure to 17-BMP and formoterol. Results after ingestion of charcoal confirmed that AUC(0,30 min) can be taken as an index of lung bioavailability and that more than 30% of the inhaled dose of extra-fine BDP/formoterol 100/6 µg was delivered to the lung using the pMDI alone.

CONCLUSIONS

The use of AeroChamber Plus™ optimizes the delivery of BDP and formoterol to the lung in subjects with inadequate inhalation technique. The total systemic exposure was not increased, supporting the safety of extra-fine BDP/formoterol pMDI with AeroChamber Plus™.

Comparative lung bioavailability of fluticasone/salmeterol via a breath-actuated spacer and conventional plastic spacers

PURPOSE

This study compares the in vivo relative lung bioavailability of Hydrofluoroalkane (HFA) Seretide delivered via unprimed and unwashed Aerochamber Plus (AP) or Volumatic (VM) spacers, a integrated breath-actuated vortex Synchro-Breathe (SB) device and an Evohaler pMDI (EH) device using adrenal suppression and early fall in serum potassium (K) as surrogates for respirable dose.

METHODS

Seventeen healthy volunteers completed this randomised double-blind, double-dummy crossover study. Single doses of placebo/Seretide 250 (total dose ex valve fluticasone 2000 mcg/salmeterol 200 mcg) were administered via the devices. Overnight urinary cortisol/creatinine (OUCC) and serum K were measured at baseline and after each dose.

RESULTS

Significant suppression of OUCC and K occurred from baseline with the SB, AP and VM but not with the EH devices. The geometric mean fold suppression (95% confidence interval, p) was: EH, 1.59 (0.80-3.14, p=0.40); AP, 4.26 (3.01-6.02, p<0.001); VM, 3.11 (1.99-4.78, p<0. 001); SB, 3.29 (2.04-5.24, p<0.001). For K, the arithmetic mean fall (mmol/l) (95% confidence interval; p) was: EH, -0.10 (-0.25-0.05, p=0.18); AP, -0.23 (-0.41 to -0.04, p=0.02); VM, -0.22 (-0.44 to -0.01, p=0.04); SB, -0.28 (-0.42 to -0.13, p=0.001).

CONCLUSIONS

The breath-actuated SB device was comparable to 'out of the box' small and large volume spacers and produced similar improvements in relative systemic lung bioavailability for fluticasone and salmeterol.

Systemic bioavailability of hydrofluoroalkane (HFA) formulations of fluticasone/salmeterol in healthy volunteers via pMDI alone and spacer

AIM

To compare a test version of HFA fluticasone/salmeterol (FP/SM) combination inhaler (Neolab, UK) with the reference product Seretide (GlaxoSmithKline, UK).

METHODS

An in vitro Anderson cascade impactor was used to compare the fine particle dose (<4.7 microm). Two separate randomized cross-over studies were performed to compare the systemic bioavailability of test vs. reference (T vs. R) formulations of FP/SM 250/25 microg pMDI in healthy volunteers. In study 1 blood pharmacokinetic analysis using oral charcoal block was performed over 24 h following a single dose of four puffs via pMDI alone. In study 2 systemic bioactivity was measured following single doses of four and eight puffs via a spacer device: serum potassium (K(+)) to reflect SM, and overnight urinary cortisol : creatinine (OUCC) for FP. An early pharmacokinetic profile was also assessed over 120 min.

RESULTS

The in vitro fine particle dose was similar for test vs. reference pMDI alone and via spacer. The results of both studies were consistent: No significant differences between formulations were seen in terms of FP kinetics. Analysis of SM kinetics revealed superiority of the test product. No significant dose-response or difference in T : R ratio was noted for OUCC. Fall in K(+) revealed a significant dose-response with a non-significant T : R ratio.

CONCLUSIONS

The in vitro fine particle dose may not predict pharmacokinetic and systemic pharmacodynamic outcomes. Single dosing studies with fluticasone/salmeterol 250/25 microg via pMDI or with spacer showed pharmacokinetic equivalence with FP, but not SM. No significant difference between formulations was seen with either adrenal suppression or hypokalaemia.

A novel breath-actuated integrated vortex spacer device increases relative lung bioavailability of fluticasone/salmeterol in combination

BACKGROUND

Spacer devices facilitate respirable drug delivery. A novel breath-actuated antistatic spacer with integrated vortex chamber (Synchro-Breathe) device has been developed, which is compact,portable and user friendly as compared to conventional spacers which are bulky and cumbersome. The relative bioavailability to the lung of inhaled fluticasone and salmeterol combination is primarily dependent on respirable dose delivery and can be reliably quantified using adrenal suppression and early fall in serum potassium (marker of systemic beta-2 adrenoreceptor response) as surrogate markers for delivered lung dose.

AIMS AND OBJECTIVES

To compare the in vivo relative bioavailability to the lung of Hydrofluoroalkane(HFA) Seretide delivered via Synchro-Breathe (SB); an optimally prepared 750 ml large volume plastic spacer, Volumatic (VM); and conventional Evohaler pMDI (EH).

METHODS

Nineteen healthy volunteers completed the study using a randomised double blind, double dummy crossover design. Single doses of placebo or Seretide HFA 250 (total dose ex-valve: fluticasone 2000 mcg/salmeterol 200 mcg) were administered via SB, VM and EH. Overnight urinary cortisol creatinine (OUCC) and serum potassium (K) were measured at baseline and after each dose as systemic surrogates of relative respirable dose delivery for the fluticasone and salmeterol moieties, respectively.

RESULTS

Significant suppression of OUCC and K occurred from baseline with SB and VM but not EH devices(geometric mean fold suppression, 95% CI, p and arithmetic mean fall mmol/L, 95% CI, respectively); EH:1.51(0.43-1.01), p 1/4 0.06; VM: 2.52(1.57-4.04), p < 0.001; SB: 2.66(1.57-4.49), p < 0.001(equating to 33.8%,60.2% and 62.3% falls, respectively). For K, the falls for EH were 0.09(0.25 to 0.07), p 1/4 0.69; VM: 0.27(0.46 to 0.08), p 1/4 0.003; SB: 0.32(0.53 to 0.11), p 1/4 0.002 (equating to 2.2%, 6.8%, and 8.06% fall,respectively). There were no significant differences between SB and VM.

CONCLUSION

The breath-actuated Synchro-Breathe device was comparable to an optimally prepared Volumatic spacer, and resulted in commensurate improvement in relative lung bioavailability for both fluticasone and salmeterol moieties compared to pMDI.

In vivo comparison of the relative systemic bioavailability of fluticasone propionate from three anti-static spacers and a metered dose inhaler

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Conventional spacers help overcome problems with co-ordination and may improve lung deposition and decrease oropharyngeal impaction. Antistatic spacers eliminate electrostatic charge and may hence improve respirable dose delivery. The systemic bioavailability of inhaled fluticasone propionate is primarily dependent on delivery by the pulmonary route and hence the performance of antistatic spacers can be evaluated using adrenal suppression as a sensitive surrogate for relative bioavailability to the lung after an inhalation.

WHAT THIS STUDY ADDS

This study compares the relative bioavailability to the lung of inhaled fluticasone delivered via conventional pressurized metered dose inhalers (pMDI) and three antistatic spacers (plastic Zerostat-V, plastic Aerochamber Max, and metal Nebuchamber) in patients with asthma. All three antistatic spacers when compared with pMDI significantly increased the relative bioavailability to the lungs of inhaled fluticasone in terms of relative adrenal suppression, and there were no significant differences between the plastic and metal antistatic spacers.

AIMS

The systemic bioavailability of inhaled fluticasone propionate (FP) depends primarily on lung absorption and can be quantified by measuring suppression of overnight and early morning urinary cortisol/creatinine (OUCC and EMUCC, respectively). The aim of the study was to determine the relative bioavailability of hydrofluoroalkane (HFA) FP to the lungs via anti-static plastic (Zerostat-V and Aerochamber Max), metal (Nebuchamber) anti-static spacers and metered dose inhaler [Flixotide Evohaler (EH) (pMDI)].

METHODS

A randomized, double-blind, double-dummy, four-way crossover design was used. Eighteen mild to moderate asthmatics received single doses of placebo/HFA-FP 2 mg via the 280-ml Zerostat-V (ZS); 250-ml Nebuchamber (NC); 197-ml Aerochamber Max (AC); and pMDI (EH). Measurements of OUCC and EMUCC were made at baseline and 10 h after each dose.

RESULTS

Significant suppression of OUCC and EMUCC occurred from baseline with all three spacers, but not Evohaler (geometric mean fold suppression, 95% confidence interval): ZS, 2.74 (1.75, 4.30), P < 0.001; NC, 3.31 (1.81, 6.06), P < 0.001; AC, 4.98 (3.39, 7.31), P < 0.001; and for EH this was 1.42 (0.92, 2.21), P= 0.169 (equating to a 64, 70, 80 and 30% fall in OUCC via the ZS, NC, AC and EH devices, respectively). There were significant differences between all three spacers vs. EH. When compared with the Evohaler, the Zerostat V resulted in 48% greater suppression (P= 0.009); the Nebuchamber 57% greater suppression (P= 0.001); and the Aerochamber Max 71% greater suppression of OUCC (P < 0.001).

CONCLUSION

All three antistatic spacers significantly increased the relative systemic bioavailability of HFA-FP compared with the standard pMDI. --EudraCT Database trial registration number: 2005-005557-22.

Respirable dose delivery of fluticasone propionate from a small valved holding chamber, a compact breath actuated integrated vortex device and a metered dose inhaler

AIMS

To compare the respirable dose delivery of the hydrofluroalkane fluticasone propionate (HFA-FP) via an optimally prepared Aerochamber Plus spacer (AP), via a Synchro-Breathe (SB) device, and pMDI Evohaler (EH).

METHODS

Seventeen mild to moderate asthmatics completed the study using a randomized, double-blind, double-dummy, three way crossover design. Single doses of placebo or HFA-FP 2.0 mg were administered via the EH, AP, and SB devices. The overnight urinary cortisol : creatinine ratio (OUCC) was measured at baseline and after each dose.

RESULTS

Significant suppression of OUCC occurred from baseline with AP and SB but not EH devices (geometric mean fold suppression, 95% CI): AP: 3.18 (2.29, 4.36), P < 0.001; SB: 1.79 (1.31, 2.40), P = 0.001; EH: 1.12 (0.69, 1.44), p = 0.37 (equating to 68%, 45% and 9% falls, respectively). Significant differences in OUCC between devices were as follows: (geometric mean fold difference, 95% CI): AP vs. EH. 2.83 (2.09, 3.82), P < 0.001; AP vs. SB: 1.78 fold (1.21, 2.60), P = 0.003; SB vs. EH: 1.59 (1.09, 2.31), P = 0.013 (equating to 65%, 44% and 37% differences, respectively).

CONCLUSIONS

The use of an optimally prepared AP spacer and breath actuated SB device, when compared with pMDI, significantly increased the respirable dose of HFA-FP.

Assessment of the long-term safety of inhaled ciclesonide on growth in children with asthma

OBJECTIVE

To assess the effects of the new inhaled corticosteroid ciclesonide on growth in children with asthma.

METHODS

We performed a multicenter, randomized, double-blind, placebo-controlled study to assess the effects of inhaled ciclesonide on growth in children with mild, persistent asthma. After a 6-month run-in period, 661 prepubertal children who were aged 5.0 to 8.5 years were randomly assigned to once-daily morning treatment for 1 year with ciclesonide 40 or 160 microg (ex-actuator) or placebo, followed by a 2-month follow-up period. The primary end point was the linear growth velocity (linear regression estimate) over the double-blind treatment period. Growth was recorded as the median of 4 stadiometer measurements. Adverse events and 10-hour overnight and 24-hour urinary free cortisol levels were also assessed.

RESULTS

Mean linear growth velocity during run-in was comparable between groups: 160 microg, 6.20 cm/year; 40 microg, 6.59 cm/year; placebo, 6.49 cm/year. Mean differences from placebo (5.75 cm/year) in growth velocity over the double-blind treatment period were -0.02 cm/year for ciclesonide 40 microg and -0.15 cm/year for ciclesonide 160 microg. Both ciclesonide treatments were noninferior to placebo with respect to growth velocity. The overall incidence of adverse events was comparable between groups, and no significant changes in 10-hour overnight or 24-hour urinary free cortisol levels were noted between groups during the double-blind treatment period.

CONCLUSIONS

Ciclesonide demonstrated no detectable effect on childhood growth velocity, even at the highest dosage, which may ease concerns about systemic adverse events.

Hypothalamic-pituitary-adrenal axis suppression in asthmatic children on inhaled corticosteroids (Part 2)--the risk as determined by gold standard adrenal function tests: a systematic review

The evidence for hypothalamic-pituitary-adrenal axis (HPA) suppression by inhaled corticosteroids (ICS) was found to be conflicting. Reviewers have not distinguished between gold standard and basal adrenal function tests. The utility of the latter is limited by physiological and pathological variability as well as by methodological concerns. The risk of HPA suppression in asthmatic children and adolescents treated with ICS, as determined by gold standard adrenal function tests, needs to be established. A systematic review of the literature from January 1973 to July 2005 was performed. The Medline and Cochrane databases were searched, the reference lists of retrieved articles were inspected and pharmaceutical companies were approached. Randomized-controlled trials, cohort and case-control studies designed to detect HPA suppression caused by ICS, diagnosed by the insulin tolerance test (ITT) or the metyrapone test, performed on asthmatics of all ages not on oral steroids, were included and assessed for methodological quality. Of the 22 identified studies only four met the criteria for inclusion. All of these were published before 1988 and only one was methodologically sound. The cohort study showed that the baseline risk for HPA suppression is 0% while the absolute risk is 100% in asthmatic children treated with a beclomethasone dipropionate metered dose inhaler at a dose of 250-600 mug/m(2)/day for 6-42 months. As suggested by other observations these results could be generalized to other ICS. They may be of clinical significance especially if children are subjected to stress. Further research is needed to establish the cumulative dose for all ICS at which HPA suppression will be precipitated. Guidelines for future trials are suggested.

Evaluation of tests of hypothalamic-pituitary-adrenal axis function used to measure effects of inhaled corticosteroids

OBJECTIVES

To review the evidence supporting the evaluation of hypothalamic-pituitary-adrenal (HPA) axis function as a measure of systemic exposure and clinical adverse events, discuss factors that affect systemic exposure to inhaled corticosteroids (ICSs), and review the effects of various ICSs that are currently available or under development on HPA axis function from a therapeutic perspective.

DATA SOURCES

Randomized published clinical trials and review articles on the topic of HPA axis suppression were retrieved in MEDLINE. Searches dating back to 1988 were restricted to human studies published in English.

STUDY SELECTION

Studies that evaluated HPA axis function and the methods used to measure its activities and the effects of ICSs (fluticasone propionate, budesonide, beclomethasone dipropionate, mometasone furoate, and ciclesonide) were selected.

RESULTS

Factors that influence adverse events caused by ICSs include pharmacokinetic and pharmacodynamic properties, delivery devices, and therapeutic dose and duration. Basal measurements of blood and urinary cortisol levels, reflecting basal HPA axis function, are the most sensitive markers for assessing systemic ICS bioavailability but, compared with dynamic stimulation tests, are poor clinical predictors of adrenal dysfunction.

CONCLUSIONS

Basal serologic and urinary cortisol tests provide the best measures of assessing and comparing systemic ICS exposure. Long-term clinical studies are needed to determine whether such tests are predictive of ICS toxicity.

[Fluticasone propionate in children and infants with asthma]

The known efficacy of fluticasone propionate in adults, comparable at half-dosage of corticosteroids has been validated by the market authorization (MA) and by the national and international guidelines for beclomethasone. This could be partly explained by its pharmacological properties, affinity for glucocorticosteroid receptors, lung deposition and lipophilicity. The limited systemic adverse events is due to its low bioavailability, optimal hepatic clearance, high plasma protein binding. The efficacy in asthmatic children has been confirmed in clinical studies showing a "plateau" efficacy between 100 and 200 microg/d for the majority of children. Most children are controlled by such dosages: the added value of increasing posology on asthma control exists but is small. A high off-label posology does not allow more quickly asthma control and therefore is not justified. A twice daily dosing is more efficient, particularly for initiation of maintenance therapy, than a once daily dosing. A literature survey confirms that, at MA recommended daily doses in children (100-200 microg), fluticasone propionate has no clinically significant effect either on hypothalamic-pituitary-adrenal (HPA) axis (basal function or stimulation tests), bone or growth velocity. However, high daily doses (higher to 500 microg/day) for long periods expose to systemic adverse effects with measurable consequences on growth rate, bone density (decreasing biochemical makers of bone formation) and HPA function. Several cases of adrenal insufficiency that may have led to acute adrenal crisis have been reported in 4- to 10-year-old children receiving fluticasone propionate in doses between 500 to 2000 microg daily. In case of surgery or infection, a preventive treatment of adrenal insufficiency with hydrocortisone should be proposed for children treated for more than 6 months with such high daily doses. Such children need definitely an advice from paediatricians specialized in chest diseases as well as in endocrinology. It is important to recall that the clinical benefit of daily doses of inhaled corticosteroids higher than recommended is low and that the good use of inhaled corticosteroids particularly in children lays on the careful search of the minimal efficient daily doses.

Use of the low-dose corticotropin stimulation test for the monitoring of children with asthma treated with inhaled corticosteroids

OBJECTIVE

Subnormal hypothalamic-pituitary-adrenal (HPA) function and rare cases of adrenal crisis have been reported in asthmatic children treated with inhaled corticosteroids. We investigated subnormal HPA activity and followed up affected patients until recovery of normal HPA functions.

STUDY DESIGN

100 children with persistent asthma underwent low-dose corticotropin testing, with the administration of 1 microg of 1-24 ACTH intravenously. Treatments were beclomethasone dipropionate as a metered-dose inhaler, n = 14, budesonide as a dry-powder inhaler, n = 16, fluticasone propionate as a metered-dose inhaler n = 31 or a dry-powder inhaler n = 39. The mean commercially labelled dose was 520 +/- 29 microg/day (mean +/- SEM, range: 160-1,000) and the equipotent dose (which compares the efficiency of these drugs for treating asthma and their responsibility for systemic effects) was 890 +/- 55 microg/day (range: 200-2,000).

RESULTS

The mean stimulated cortisol level +/- SEM (and range) of the patient was 482 +/- 12 (148-801), and that of 40 age-matched controls was 580 +/- 12.5 (439-726), (SD = 79). The result was subnormal (more than 2 SD below the mean of the controls) in28 of the 100 patients. One-four stepwise decreases of 10-100% in the daily equipotent doses received by the patients with abnormal low-dose corticotropin testing results led to normal results in subsequent low-dose corticotropin testing in 27 retested patients. The mean time interval between two tests was 5 months (range: 2-6 months) and the mean period required for normalization of the test was 13 months (range: 2-21). Only one case of asthma exacerbation and no adrenal crisis were observed over these periods.

CONCLUSIONS

Decreasing daily equipotent doses led to recovery of normal HPA function without asthma exacerbation. Thus, a revision of the doses of inhaled corticosteroids used in asthmatic children with a progressive decrease to the consensus-recommended doses should decrease the systemic effects of inhaled corticosteroids, while minimizing the risk of asthma exacerbation.

Effects of glucocorticoids on the hypothalamic-pituitary-adrenal axis in children and adults

Inhaled and intranasal corticosteroids are widely used as effective, first-line treatments for asthma and allergic rhinitis. Despite a good safety profile of these formulations, there is increasing concern about their propensity to produce systemic adverse effects. Suppression of the hypothalamic-pituitary-adrenal axis is one of the most important potential complications. This article reviews the effects of inhaled and intranasal corticosteroids on the hypothalamic-pituitary-adrenal axis function in adults and children.

Effects of mometasone furoate dry powder inhaler and beclomethasone dipropionate hydrofluoroalkane and chlorofluorocarbon on the hypothalamic-pituitary-adrenal axis in asthmatic subjects

STUDY OBJECTIVES

Mometasone furoate dry powder inhaler (MF-DPI) [400 mug] is an inhaled corticosteroid (ICS) that is effective in the treatment of asthma. MF-DPI has a low potential for suppression of the hypothalamic-pituitary-adrenal (HPA) axis at its clinical dose. The effect of MF-DPI, 400 microg qd, on the HPA axis was compared to that of beclomethasone dipropionate (BDP) using hydrofluoroalkane (HFA) and chlorofluorocarbon (CFC) propellants via metered-dose inhalers (MDIs) twice daily.

DESIGN AND INTERVENTIONS

This randomized, third-party blind, parallel-group study compared the effects of MF-DPI 400 mug one puff qd in the morning (n = 18), HFA-BDP 200 microg two puffs MDI bid (n = 18), and CFC-BDP 400 microg two puffs MDI bid (n = 17) for 14 days on the area under the 24-h serum cortisol concentrations curve (AUC(0-24)) and on total 24-h urinary free cortisol excretion in mild asthmatic subjects. Effects on morning/evening peak expiratory flow (PEF) and on inhaled albuterol use were also assessed. Adverse events that occurred during or > or = 30 days after the study were recorded.

RESULTS

The mean decrease from baseline in the serum cortisol concentrations AUC(0-24) in the MF-DPI group was significantly less than in either the HFA-BDP (p = 0.024) or the CFC-BDP (p = 0.011) groups. Decreases in serum cortisol concentrations AUC(0-24) in the two BDP groups did not differ from one another. The MF-DPI group trended toward higher morning and evening PEF than either BDP group. Treatment-associated adverse events were reported by seven subjects in the MF-DPI group, vs one subject in the HFA-BDP and three subjects in the CFC-BDP groups; these were mild, and no subject discontinued treatment due to an adverse event.

CONCLUSIONS

Fourteen days of treatment with MF-DPI 400 microg qd was associated with a significantly lesser decrease in the serum cortisol concentrations AUC(0-24) compared with HFA-BDP 200 microg MDI or CFC-BDP 400 microg MDI bid.

Effects of high-dose inhaled fluticasone propionate on the hypothalamic-pituitary-adrenal axis in asthmatic patients with severely impaired lung function

BACKGROUND

The effects of high-dose fluticasone propionate therapy on dynamic cortisol stimulation in severe asthma are unknown.

OBJECTIVE

To evaluate the human corticotropin-releasing factor (hCRF)-stimulated plasma cortisol response to fluticasone propionate therapy in severe asthmatic patients with impaired airway caliber (forced expiratory volume in 1 second [FEV1] < 60% of predicted) and in control subjects.

METHODS

Ten severe asthmatic patients (mean FEV1, 47% of predicted) and 10 controls (mean FEV1, 104% of predicted) received fluticasone propionate, 2,000 microg/d, via a 750-mL primed spacer for 2 weeks. Plasma cortisol levels before and after hCRF stimulation and overnight 10-hour urinary cortisol excretion corrected for creatinine concentration (OUCC) were measured at baseline after washout and 12 hours after the last dose of fluticasone propionate.

RESULTS

Baseline values before fluticasone propionate use were not significantly different in asthmatic patients vs controls for plasma cortisol before and after hCRF stimulation and OUCC. Comparing values at baseline vs after fluticasone propionate use, there was no significant suppression of plasma cortisol levels before (378.2 vs 357.4 nmol/L) or after (510.5 vs 507.9 nmol/L) hCRF stimulation or OUCC (8.2 vs 7.5 nmoL/mmoL) in asthmatic patients. In controls, all outcomes were significantly suppressed comparing values before vs after fluticasone propionate therapy: plasma cortisol levels before (423.5 vs 200.2 nmol/L; P = .002) and after (503.5 vs 291.1 nmol/L; P = .001) hCRF stimulation and OUCC (6.5 vs 2.4 nmol/mmol; P = .002).

CONCLUSION

Patients with severe persistent asthma and impaired airway caliber seem to be protected from developing systemic adverse effects with high-dose fluticasone propionate therapy, as evaluated by basal and dynamic measures of hypothalamic-pituitary-adrenal axis activity.

The presence of emphysema does not affect the systemic bioactivity of inhaled fluticasone in severe chronic obstructive pulmonary disease

AIMS

To assess the systemic bioactivity of fluticasone proprionate (FP) 2000 micro g daily on sensitive adrenal and bone markers in severe chronic obstructive pulmonary disease (COPD) patients with or without significant emphysema.

METHODS

Ten patients without emphysema (COPD group: age 55 years, FEV(1) 51% predicted and DL(CO) 83% predicted) and 10 patients with emphysema (COPDE group: age 59 years, FEV(1) 43% predicted and DL(CO) 49% predicted) received FP 2000 micro g daily via a spacer for 2 weeks. There was a 1-week washout period prior to FP treatment where patients were given salmeterol and oxitropium, after stopping their usual inhaled corticosteroids for the duration of the study. Measurements including overnight 10 h urinary cortisol excretion corrected for creatinine (OUCC) and serum osteocalcin concentrations were performed at baseline following washout and after 2 weeks of FP.

RESULTS

Values for OUCC and serum osteocalcin concentrations pre- and post-FP were not significantly different between the COPD and COPDE groups. There was significant suppression of OUCC (nmol mmol(-1)) by FP treatment within the COPD group (P = 0.03): 7.86 vs 4.64 (95% CI on the difference 0.47, 5.98), and within the COPDE group (P = 0.006): 7.13 vs 4.27 (95% CI on the difference: 1.03, 4.69). Likewise, there was significant suppression of osteocalcin concentration (nmol l(-1)) by FP treatment within the COPD group (P = 0.04): 7.24 vs 6.34 (95% CI on the difference: 0.01, 1.78), and within the COPDE group (P = 0.03): 6.92 vs 5.72 (95% CI on the difference: 0.12, 2.29).

CONCLUSIONS

Severe COPD patients who are receiving high dose FP are susceptible to the development of systemic adverse effects, irrespective of the presence of emphysema.

Antiasthmatic drug delivery in children

Asthma therapy can be administered to children via a number of routes, including oral, inhaled (via a multiplicity of devices), rectal, intravenous, subcutaneous, and intramuscular. The inhaled route is used most often. This can reduce, but never eliminate, systemic absorption. Swallowed aerosolized medication is subject to hepatic first-pass metabolism, but this metabolic route is bypassed by the drug impacting on the airway, including the pharynx. Although there are a large number of studies from a laboratory setting about drug deposition characteristics, there is very little evidence from community-based studies about what families think actually works well in the everyday treatment of the child. However, it is clear that altering the inhaler device can result in marked changes in the dose administered, and any such change should be part of a review of the dose of prescribed medication. Nebulizers are being used much less frequently, and in particular, all but the most severe exacerbations can be treated at least as effectively with equivalent dosages of beta(2)-adrenoceptor agonists from a large volume spacer.

Single-dose study to compare the pharmacokinetics of HFA flunisolide and CFC flunisolide

The hydrofluoroalkane (HFA) formulation of the inhaled corticosteroid flunisolide is a modification of the original chlorofluorocarbon (CFC) formulation. HFA flunisolide replaces CFC with an HFA propellant and uses a built-in spacer in its pressurized metered-dose inhaler. The average HFA flunisolide particle size is 1.2 microm compared with 3.8 microm for the CFC formulation. The smaller particle size improves lung targeting, allowing a reduction in the HFA flunisolide dose relative to CFC flunisolide while maintaining comparable efficacy. In a study of 12 healthy men, pharmacokinetic parameters were determined after single doses of 1000 microg CFC flunisolide delivered without a spacer, 340 microg HFA flunisolide delivered through a spacer, and 516 microg HFA flunisolide delivered without a spacer. A standard noncompartmental analysis of the concentration data was performed and mean (+/- S.D.) pharmacokinetic values were reported. Peak plasma concentrations (observed C(max)) were similar for the three treatments. Area under the curve up to the time corresponding to the last measurable concentration (AUC(0)(-)(tlast)) was similar for the CFC and HFA flunisolide, plus spacer groups (4.4 +/- 1.6 ng x h/mL and 5.0+/- 4.2 ng x h/mL, respectively); however, AUC(0)(-)(tlast) for the HFA flunisolide without spacer group was comparatively lower than for the CFC group (3.5 +/- 1.6 ng x h/mL). Observed C(max) and AUC(0)(-)(tlast) for 6 beta-OH flunisolide, the first-pass metabolite of flunisolide and an indicator of oropharyngeal deposition, were significantly higher in the CFC flunisolide group than in either HFA flunisolide group.

Flunisolide HFA vs flunisolide CFC: pharmacokinetic comparison in healthy volunteers

Two preparations of flunisolide, an inhaled corticosteroid, were compared in a parallel, multiple-dose study of 31 healthy volunteers. The new flunisolide preparation substitutes hydrofluoroalkane (HFA) for chlorofluorocarbon (CFC) as a propellant and incorporates a spacer into its pressurized metered-dose inhaler (pMDI). In this study, subjects were randomly assigned to receive flunisolide CFC 1000 microg bid; flunisolide HFA 170 microg bid; or flunisolide HFA 340 microg bid. Dosing was continued for 13.5 days. Plasma samples were analyzed after the first dose on day 1 and again after 13.5 days of treatment. No significant differences in day 1 dose-adjusted peak plasma concentrations (C(max)) were observed. Dose proportionality in C(max) and area under the concentration--time curves (AUC) was observed for the flunisolide HFA 170 and 340 microg bid groups on days 1 and 14. Day 1 mean dose-adjusted AUC was significantly greater in the flunisolide CFC 1000 microg bid group than in either flunisolide HFA group, indicating greater systemic availability of flunisolide CFC. Oral clearance and volume of distribution were significantly higher for flunisolide CFC than for flunisolide HFA. This may be due to greater oropharyngeal deposition by the flunisolide CFC formulation. Another indicator of greater flunisolide CFC oropharyngeal deposition was observed in C(max) and AUC(0--tlast) values for 6beta-OH flunisolide, the first-pass metabolite of flunisolide. The values of these pharmacokinetic parameters were significantly higher in the flunisolide CFC group than in the 340 microg bid flunisolide HFA group on days 1 and 14. However, this was not the case for cortisol values where flunisolide HFA accounted for less oropharyngeal deposition and more targeted delivery without adverse events. The study demonstrated that flunisolide HFA administered through a pMDI with built-in spacer was safe and well tolerated in healthy volunteers.

Suppression of hypothalamic-pituitary-adrenal axis activity with inhaled flunisolide and fluticasone propionate in adult asthma patients

BACKGROUND

Suppression of the hypothalamic-pituitary-adrenal (HPA) axis, a potential systemic effect of inhaled corticosteroid therapy, can be quantified by monitoring serum, urinary, and salivary cortisol levels.

OBJECTIVES

1) Compare the effects on HPA axis of the inhaled corticosteroids flunisolide and fluticasone propionate versus placebo and oral prednisone. 2) Estimate dose-potency ratio for HPA-axis suppression.

METHODS

Multicenter, randomized, placebo-controlled, open-label, 21-day trial. Active regimens were flunisolide 500 and 1,000 microg, twice daily; fluticasone propionate 110, 220, 330, and 440 microg, twice daily; and prednisone, 7.5 mg daily. Enrolled patients were nonsmokers, 18 to 50 years of age, with persistent mild-to-moderate asthma and had not used oral, nasal, or inhaled corticosteroids for 6 months before study. Main outcome measures were area under serum cortisol concentration curve for 22 hours (AUC(0-22h)); 24-hour urinary cortisol level; and 8 AM salivary cortisol level.

RESULTS

One hundred fifty-three patients were randomly assigned to active treatment or placebo; 125 patients completed the study and were at least 80% compliant with their regimens. Both fluticasone propionate and flunisolide caused dose-dependent suppression of HPA axis, which was statistically greater for fluticasone propionate (P = 0.0003). Dose-potency ratio showed 4.4 times more serum-cortisol suppression/microgram increase in dose with fluticasone propionate than with flunisolide. Diurnal pattern of serum cortisol suppression was persistent with fluticasone propionate and "remitting" with flunisolide. Salivary and urinary cortisol data were qualitatively similar to serum cortisol results.

CONCLUSIONS

Fluticasone caused significantly more suppression of HPA axis than flunisolide. Flunisolide may provide a safe option for patients with asthma requiring long-term inhaled corticosteroid therapy.

Safety of inhaled and intranasal corticosteroids: lessons for the new millennium

Although inhaled and intranasal corticosteroids are first-line therapy for asthma and allergic rhinitis, there has recently been an increasing awareness of their propensity to produce systemic adverse effects. The availability of more potent and lipophilic corticosteroids and new chlorofluorocarbon (CFC)-free formulations has focused attention on these safety issues. The main determinant of systemic bioavailability of these drugs is direct absorption from the lung or nose, where there is no first-pass inactivation. Consequently, the systemic bioavailability of inhaled corticosteroids is greatly influenced by the efficiency of the inhaler device. Thus, when comparing different inhaled corticosteroids it is imperative to consider the unique drug/device interaction. The pharmacokinetic profile is important in determining the systemic bioactivity of inhaled and intranasal corticosteroids. For highly lipophilic drugs, such as fluticasone propionate or mometasone furoate, there is preferential partitioning into the systemic tissue compartment, and consequently a large volume of distribution at steady state. In contrast, drugs with lower lipophilicity, such as triamcinolone acetonide or budesonide, have a smaller volume of distribution. The systemic tissue compartment may act as a slow release reservoir, resulting in a long elimination half-life for the lipophilic drugs. For intranasal corticosteroids, a high degree of lipophilicity diminishes water solubility in mucosa and therefore increases the amount of drug swept away by mucociliary clearance before it can gain access to tissue receptor sites. This may reduce the anti-inflammatory efficacy in the nose, but might also reduce the propensity for direct systemic absorption from the nasal cavity. The hydrofluoroalkane (HFA) formulations of beclomethasone dipropionate are solutions and exhibit a much higher respirable fine particle dose than do the CFC formulations. Dose-response studies with one of the HFA formulations have shown therapeutic equivalence at half the dosage, with little evidence of adrenal suppression at dosages up to 800 microg/day. A lack of similar studies for another of the available HFA formulations has led to a discrepancy in the recommendations for equivalence. Although in vitro studies have pointed to a similar fine particle distribution for the HFA and CFC formulations of fluticasone propionate, this is not supported by in vivo data for lung bioavailability, suggesting that care will be required when switching these formulations. Prescribers of inhaled and intranasal corticosteroids should be aware of the potential for long term systemic effects. The safest way to use these drugs is to 'step-down' to achieve the lowest possible effective maintenance dosage.