Clinical efficacy and safety of fluticasone propionate 250 microg twice daily administered via a HFA 134a pressurized metered dose inhaler to patients with mild to moderate asthma. French study group

This study compared the efficacy and safety of the fluticasone propionate 125 microg pressurized metered dose inhaler (pMDI) propelled by either hydrofluoroalkane (HFA) 134a or chlorofluorocarbon (CFC) propellants, in adult patients with asthma. HFA 134a is a non-ozone depleting propellant used as a replacement for the CFC propellants 11 and 12 which are being phased out in accordance with the Montreal Protocol. Three hundred and eighty patients with mild to moderate asthma and 'room for improvement' in their treatment were randomized to receive fluticasone propionate 250 microg twice daily via pMDIs propelled by either CFC propellants 11 and 12 (n = 195) or HFA 134a (n = 185). Fluticasone propionate significantly improved lung function over the 4-week treatment period in both treatment groups. The improvement in mean morning peak expiratory flow (PEF) after 7 days of treatment was approximately 12 l min(-1) in both groups, rising to approximately 22 l min(-1) at the end of the 4-week treatment period. The adjusted mean difference between the two formulations over weeks 1-4 was -1 l min(-1) (90% confidence interval: -7, 5 l min(-1)), confirming their equivalence. Clinical comparability was also demonstrated with respect to secondary efficacy variables, including daily symptom scores, evening PEF and clinic visit expiratory measurements. There were no clinically relevant differences in adverse events or serum cortisol levels between the two groups. The fluticasone propionate 125 microg HFA 134a pMDI is an effective and well tolerated product and is a suitable replacement for the fluticasone propionate 125 microg CFC pMDI at a microgram equivalent dose.

Clinical efficacy and safety of fluticasone propionate 1 mg twice daily administered via a HFA 134a pressurized metered dose inhaler to patients with severe asthma. U.K. study group

A randomized, double-blind, cross-over study was conducted to assess the efficacy and safety of fluticasone propionate 1 mg twice daily administered via a pressurized metered dose inhaler (pMDI) containing the new non-chlorofluorocarbon (CFC) propellant (HFA 134a), or the established CFC propellants 11 and 12 in patients with severe asthma. The study comprised a 2-week run-in period followed by two 6-week treatment periods, with no washout period in between. One hundred and nineteen symptomatic adult patients with severe asthma, who were receiving inhaled beclomethasone 2-4 mg day(-1) or equivalent, were randomized to treatment. Patients were randomized to one of two sequence groups (sequence 1: HFA 134a pMDI then CFC pMDI or sequence 2: CFC pMDI then HFA 134a pMDI). The sequence groups differed with respect to mean peak expiratory flow (PEF) at baseline; however, the magnitude of the increase in PEF from baseline during treatment was similar in the two sequence groups. Mean PEF at baseline was 334 l min(-1) in sequence group 1 (HFA 134a-->CFC pMDI) and this increased to 357 l min(-1) and 366 l min(-1) during treatment with the HFA 134a and CFC pMDI, respectively. In sequence group 2 (CFC-->HFA 134a pMDI) mean PEF at baseline was 297 l min(-1) and this increased to 336 l min(-1) and 328 l min(-1) during treatment with the HFA 134a and CFC pMDI, respectively. Based on an overall analysis of the two treatment groups at week 6, equivalence was demonstrated; the mean treatment difference (HFA 134a-CFC pMDI) in morning PEF was 0 l min(-1) (90% confidence interval (CI), for difference between groups: -7, 6 l min(-1)). There was a comparable improvement in secondary efficacy variables, including clinic lung function measurements, in the two treatment groups. The incidence and type of most adverse events were similar in the two treatment groups. There was no difference in the adjusted geometric mean morning serum cortisol levels after treatment with the HFA 134a and CFC pMDI. Therefore, the fluticasone propionate HFA 134a pMDI constitutes a suitable replacement for the established CFC pMDI at a microgram equivalent dose.

Equivalence of as-required salbutamol propelled by propellants 11 and 12 or HFA 134a in mild to moderate asthmatics. German Study Group

This randomized, double-blind, parallel-group study compared the efficacy and tolerability of as-required salbutamol 100 microg administered from either a chlorofluorocarbon (CFC) pressurized metered dose inhaler (pMDI; Ventolin) or from a non-CFC hydrofluoroalkane (HFA) 134a pMDI (Ventolin CFC-free) in patients with mild to moderate asthma. All patients (n = 423) continued with their standard asthma therapy, and recorded their daily use of study medication, morning and evening peak expiratory flow (PEF) and symptom scores, throughout the 4-week treatment period. Clinic lung function was measured at 2-week intervals. The median daily use of inhaled study medication remained constant at four actuations per day throughout the study in both treatment groups and statistical analysis indicated that the two formulations were equivalent. Small improvements in both treatment groups were reported in mean morning and evening PEF, clinic forced expiratory volume in 1 sec and clinic PEF and there were no significant differences between the two groups. Both formulations were well tolerated. This study indicates that as-required salbutamol 100 microg administered via a HFA 134a pMDI is as effective and safe as the currently available CFC-propelled formulation.

Therapeutic equivalence of inhaled beclomethasone dipropionate with CFC and non-CFC (HFA 134a) propellants both delivered via the Easibreathe inhaler for the treatment of paediatric asthma

Chlorofluorocarbon (CFC)-containing inhalers for use in the treatment of asthma are to be phased out under the terms of the Montreal Protocol (1). In this multi-centre, randomized, double-blind study, the therapeutic equivalence of two formulations of beclomethasone dipropionate (BDP) containing CFC or non-CFC (HFA134a) propellant, both delivered via the Easibreathe (Norton Healthcare Ltd, London, U.K.) inhaler, was determined in 229 asthmatic children. Each child received 100 microg doses of BDP (containing either CFC or HFA propellant) twice daily for 12 weeks. Both CFC and HFA formulations produced statistically and clinically significant improvements in patient's lung function and symptom scores when administered via the Easibreathe inhaler. The improvements in mean morning peak expiratory flow (PEF) were 41 l min(-1) and 34 l min(-1) for the BDP-HFA and BDP-CFC products respectively (P<0.001) and for mean evening PEF the improvements were 38 l min(-1) and 38 l min(-1), respectively (P<0.001). Similar findings were demonstrated for the other efficacy parameters. The two formulations were statistically equivalent with respect to efficacy. For mean morning PEF the estimated treatment difference (BDP-CFC/BDP-HFA ratio) was 102.6% (95% CI 99.1, 106.2). Similar equivalence was shown for the other efficacy parameters. Both products were well tolerated, with no difference in the adverse event profiles, effects on 24 h urinary cortisol or Candida colonisation. This study demonstrates that the new formulation of BDP with HFA-134a propellant is equivalent to and directly substitutable for BDP with the older CFC propellant in a dose for dose manner. This should enable a seamless transition from one product to the other when CFC containing products are eventually phased out. In addition this study has also shown that the Easibreathe inhaler is an effective delivery system for use with inhaled products for the treatment of asthma in children.

Achieving compliance in asthma management

Up to three million asthma patients take their medication using a metered dose inhaler. The drive to reduce the world-wide use of chlorofluorocarbons (CFCs) has resulted in the development of CFC-free metered dose inhalers. Nurses have an important part to play in managing the transition to CFC-free inhaler devices. This will provide an opportunity to improve levels of compliance with treatment and reduce asthma-induced morbidity and mortality

Placebo-controlled, comparative study of the efficacy and safety of triamcinolone acetonide inhalation aerosol with the non-CFC propellant HFA-134a in patients with asthma. Azmacort HFA Clinical Study Group

BACKGROUND

Triamcinolone acetonide (TAA) inhalation aerosol (Azmacort Inhalation Aerosol), a well-established corticosteroid treatment for bronchial asthma, utilizes the chlorofluorocarbon (CFC) propellant P-12, which will be phased out because of environmental concerns. Two TAA aerosol formulations have been developed using a non-chlorofluorocarbon propellant, HFA-134a (Azmacort HFA Inhalation Aerosol delivering TAA 75 microg/puff or 225 microg/puff).

OBJECTIVE

This study compared the efficacy and safety of the new 225 microg/puff formulation (TAA-HFA 225) to the marketed TAA inhalation aerosol (TAA-CFC) and to placebo in adult patients with moderate-to-severe persistent asthma.

METHODS

After a 5-day to 21-day baseline period during which all patients received TAA-CFC 150 microg/day, 538 patients were randomized to one of the following treatment schedules: TAA-HFA 450, 900, or 1800 microg/day; TAA-CFC 450 or 900 microg/day; or placebo for 12 weeks.

RESULTS

All active treatment groups showed statistically significant improvement compared with placebo in pulmonary function (FEV1, FEF25-75%, morning and evening PEF), use of rescue albuterol, and asthma symptom scores. Improvements in all variables occurred within 1 week of treatment.

CONCLUSIONS

The TAA-HFA 225 exhibited similar safety and efficacy profiles to the two equivalent doses of TAA-CFC studied. Our findings indicate that TAA-HFA is a safe and effective replacement for the currently marketed CFC-containing product. The higher strength 225 microg/puff formulation provides effective control of asthma with fewer inhalations.

Hematopoietic and reproductive toxicity of 2-bromopropane, a recently introduced substitute for chlorofluorocarbons

2-Bromopropane and hydrochlorofluorocarbons (HCFCs), whose toxicity has scarcely been known, have recently been introduced as main substitutes for chlorofluorocarbons (CFCs). A major corporation in Korea replaced CFCs with 2-bromopropane and this actually led 23 Korean workers to be the world's first 2-bromopropane intoxication victims. Out of 25 female workers in the tactile switch assembling section, 17 (68%) were diagnosed as having ovarian failure. Two affected female workers showed marked pancytopenia with markedly hypoplastic marrow. In the same section, two out of eight male workers showed azoospermia and four some degree of oligospermia. The above toxicity of 2-bromopropane was reproduced in experimental animal studies. Recently, health effects of HCFC 123, including toxic hepatitis, have been reported by several authors. The principle of replacement of toxic substances with non-toxic or less toxic chemicals is important in risk management, but substances still poorly known should not be confused with non-toxic or less toxic substances. Measures aimed at reducing exposure to chemicals with known toxicity rather than using new unknown alternatives may be a rational and effective approach to risk management.

Phaseout of chlorofluorocarbons (CFCs) in metered-dose inhalers. Highlights of the Canadian initial transition strategy

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New delivery systems and propellants

The removal of chlorofluorocarbon (CFC) propellants from industrial and household products has been agreed to by over 165 countries of which more than 135 are developing countries. The timetable for this process is outlined in the Montreal Protocol on Substances that Deplete the Ozone Layer document and in several subsequent amendments. Pressured metered dose inhalers (pMDIs) for medical use have been granted temporary exemptions until replacement formulations, providing the same medication via the same route, and with the same efficacy and safety profiles, are approved for human use. Hydrofluoroalkanes (HFAs) are the alternative propellants for CFCs-12 and -114. Their potential for damage to the ozone layer is nonexistent, and while they are greenhouse gases, their global warming potential is a fraction (one-tenth) of that of CFCs. Replacement formulations for almost all inhalant respiratory medications have been or are being produced and tested; in Canada, it is anticipated that the transition to these HFA or CFC-free pMDIs will be complete by the year 2005. Initially, an HFA pMDI was to be equivalent to the CFC pMDI being replaced, in terms of aerosol properties and effective clinical dose. However, this will not necessarily be the situation, particularly for some corticosteroid products. Currently, only one CFC-free formulation is available in Canada - Airomir, a HFA salbutamol pMDI. This paper discusses the in vitro aerosol characteristics, in vivo deposition and clinical data for several HFA pMDIs for which there are data available in the literature. Alternative delivery systems to the pMDI, namely, dry powder inhalers and nebulizers, are briefly reviewed.

Safety of long-term treatment with HFA albuterol

BACKGROUND

Chlorofluorocarbons (CFCs) used as propellants in metered-dose inhalers deplete stratospheric ozone, which results in serious public health concerns. Albuterol has been reformulated in the non-ozone-depleting propellant, hydrofluoroalkane-134a (HFA albuterol).

OBJECTIVES

The primary objective was to compare the safety of HFA albuterol to an albuterol product formulated in chlorofluorocarbon propellants (CFC albuterol) during 1 year of treatment in asthmatics. Bronchodilator efficacy of the two products was assessed as a secondary objective.

METHODS

The results from two open-label, parallel-group trials of similar design in asthmatics requiring short-acting beta-agonists for symptom control were combined. Patients took two puffs bid of either HFA albuterol or CFC albuterol for 1 year. Additional puffs of study drug were allowed as needed to control asthma symptoms. Adverse events were recorded at clinic visits. Patients self-administered study drug at quarterly visits and underwent serial spirometry during a 6-h period postdose. Bronchodilator efficacy variables, based on FEV1 response to study drug, were proportion of responders, time to onset of effect, peak percent change, time to peak effect, duration of effect, and area under the curve. Differences between products and changes over time in efficacy variables were assessed using an analysis of variance model. Regression analyses with FEV1 as a covariate were performed post-hoc to analyze changes in bronchodilator efficacy over time.

RESULTS

Demographic and baseline characteristics were similar for patients receiving HFA albuterol (n = 337) and CFC albuterol (n = 132). Total reported adverse events were similar for the two treatments. Differences in only four individual adverse events were noted: the HFA albuterol group reported more gastroenteritis and dizziness; the CFC albuterol group reported more epistaxis and expectoration. Adverse events attributed to study drug use were infrequent. No serious adverse events were related to study drug use. Predose FEV1 at quarterly visits increased to a small extent in both groups from month 0 to month 12. The bronchodilator efficacy of HFA albuterol was comparable to that of CFC albuterol at the quarterly visits, but decreased from baseline for both products over the 12 months of treatment. Use of inhaled corticosteroids, nasal corticosteroids, or theophylline did not explain the increase in predose FEV1 over time and did not protect patients from developing reduced bronchodilator efficacy by month 12. The change in predose FEV1 did not entirely account for the reduced bronchodilator efficacy over time.

CONCLUSIONS

HFA albuterol has a safety profile similar to that of CFC albuterol during chronic, scheduled use, and both drugs are well tolerated. HFA albuterol and CFC albuterol provided comparable bronchodilator efficacy, but bronchodilator efficacy decreased for both products with 1 year of use.

Switching patients with asthma from chlorofluorocarbon (CFC) albuterol to hydrofluoroalkane-134a (HFA) albuterol

Chlorofluorocarbon (CFC) propellants deplete stratospheric ozone. Production and use of CFCs, except for certain critical exemptions, has been prohibited by the Montreal Protocol. Use of CFCs as propellants in metered-dose inhalers (MDIs) is still allowed, but the U.S. Food and Drug Administration is planning the transition to alternative propellants for use in MDIs. Hydrofluoroalkane-134a (HFA), a non-ozone-depleting propellant, has been used to reformulate albuterol (HFA albuterol). This study evaluates whether comparable safety and efficacy continues for 12 weeks after patients with asthma are switched from CFC albuterol to HFA albuterol. Patients with asthma stabilized on CFC albuterol during a 12-week safety and efficacy trial were randomized to either continue receiving CFC albuterol or to be switched to receive HFA albuterol in a yearlong safety and efficacy trial. Safety and efficacy were compared over the first 12 weeks of the yearlong trial between patients who had remained on CFC albuterol and those who had been switched to HFA albuterol. Bronchodilator efficacy was evaluated by serial spirometry for 6 hr after the patients self-administered the study drug in the clinic. Safety was assessed by measuring changes in pulse rate, blood pressure, and electrocardiogram (ECG) intervals after dosing with study drug, monitoring adverse events, and performing prestudy and poststudy laboratory testing and physical examinations. No significant differences in bronchodilator efficacy between the patients continuing to receive CFC albuterol and those switched to HFA albuterol were found in the 12 weeks after the switch. No differences between the two products were found for changes in pulse rate, blood pressure, and ECG intervals. Adverse event profiles were similar for the two products, except the patients remaining on CFC albuterol reported increased asthma symptoms and rhinitis significantly more often than the patients switched to HFA albuterol. No clinically meaningful changes in laboratory tests or physical examinations were found in either treatment group. Patients with asthma switched from CFC albuterol to HFA albuterol receive comparable bronchodilation with a similar safety profile as those continuing to receive CFC albuterol.

Adrenal effects and pharmacokinetics of CFC-free beclomethasone dipropionate: a 14-day dose-response study

Since equivalent efficacy is achieved with lower doses of the reformulated beclomethasone dipropionate in the chlorofluorocarbon (CFC)-free propellant HFA-134a (HFA) than with the original CFC-beclomethasone dipropionate formulation, it is possible the HFA-beclomethasone dipropionate may have less safety concerns than the CFC formulation. Despite its chronic use, the steady-state pharmacokinetics of beclomethasone dipropionate has never been studied before. This double-blind study examined adrenal effects and pharmacokinetics after 14 days of dosing with HFA-beclomethasone dipropionate. Forty-three steroid-naïve asthmatic patients were randomised into 5 parallel groups and dosed every 12 h for 14 days with: HFA-placebo; 200, 400 or 800 microg day(-1) HFA-beclomethasone dipropionate; or 800 microg day(-1) CFC-beclomethasone dipropionate. After two weeks of dosing, the 24-h urinary free cortisol of all but one patient remained within the normal range, showing that all doses were well tolerated from a systemic safety perspective. The active HFA-beclomethasone dipropionate treatment groups showed a dose-related fall in 24-h urinary free cortisol. Total-beclomethasone (beclomethasone dipropionate and metabolites) pharmacokinetics after either the first dose of HFA-beclomethasone dipropionate or CFC-beclomethasone dipropionate were not substantially affected by subsequent doses. The extent of drug absorption from 800 microg day(-1) HFA-beclomethasone dipropionate and CFC-beclomethasone dipropionate was in the ratio of 1.7 : 1. A non-linear correlation between 24-h urinary free cortisol and the pharmacokinetic parameters was observed, reflecting smaller changes in 24-h urinary free cortisol than in pharmacokinetics as the dose was increased. No clinically meaningful change in the pharmacokinetics of beclomethasone dipropionate plus metabolites was seen on multiple dosing. The greater systemic availability of HFA-beclomethasone dipropionate was still associated with adrenal effects comparable with that of the CFC formulation at the same dose.

[Climatic changes in Scandinavia--consequences for public health]

Atmospheric composition and climate conditions are of great importance for health. Increasing consumption of fossil fuels ever since the industrial revolution has resulted in higher contents of greenhouse gases in the atmosphere. Primarily, this will increase the global temperature. Secondarily, it may change the patterns of precipitation and droughts. Higher extreme temperatures will have a negative effect on health. Climate changes can also change the living conditions of undesirable insects and microbes. The ozone gas in the atmosphere acts as a shield against the harmful ultraviolet radiation from the sun. Chlorofluorocarbons contribute to reduction of the ozone layer and increase ultraviolet radiation. Increased exposure of the skin to this radiation may cause damage such as sunburn and skin cancer. In order to avoid damage, it is of importance to wear protective clothing or use effective sunshades.

Postmarketing surveillance study of a non-chlorofluorocarbon inhaler according to the safety assessment of marketed medicines guidelines

OBJECTIVE

To evaluate the safety of a non-chlorofluorocarbon metered dose salbutamol inhaler.

DESIGN

This was a postmarketing surveillance study, conducted under formal guidelines for company sponsored safety assessment of marketed medicines (SAMM). A non-randomised, non-interventional, observational design compared patients prescribed metered doses of salbutamol delivered by inhalers using either hydrofluoroalkane or chlorofluorocarbon as the propellant. Follow up was three months.

SETTING

646 general practices throughout the United Kingdom.

SUBJECTS

6614 patients with obstructive airways disease (1667 patient years of exposure).

MAIN OUTCOME MEASURES

Proportions of patients who were: admitted to hospital for respiratory diseases, reported adverse side effects, or withdrew because of adverse affects.

RESULTS

There were no significant differences between the hydrofluoroalkane (HFA 134a) and chlorofluorocarbon inhaler groups in relation to the proportions of patients admitted to hospital for respiratory diseases (odds ratio 0.75; 95% confidence interval 0.51 to 1.08) or the proportions who reported adverse events (1.01; 0.88 to 1.17). However, more patients using the hydrofluoroalkane inhaler than the chlorofluorocarbon inhaler withdrew because of adverse events (3.8% and 0.9% respectively).

CONCLUSION

The hydrofluoroalkane inhaler was as safe as the chlorofluorocarbon inhaler when judged by hospital admissions and adverse affects. The study design successfully fulfilled the recommendations of the guidelines. Differences between postmarketing surveillance studies and randomised clinical trials in assessing safety were identified. These may lead to difficulties in the design of postmarketing surveillance studies.

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.

Lifting the fog in endoscopic surgery

This article describes a problem encountered in addressing the phase out of CFCs, the subsequent reduction in the use of the low temperature sterilization modailities and the move towards greater utilization of steam sterilization. The ban of CFCs drastically changed the way reprocessing of sterile supplies and equipment is performed in Hospitals. In 1994 at St. Boniface General Hospital Operating Room in Winnipeg, Manitoba, preparations began to meet the challenge. One of the measures taken was to review purchases for new equipment and where ever possible, choose equipment that could be sterilized using steam as opposed to using Ethylene Oxide sterilization. Medical device companies responded to the CFC ban by modifying the manufacture of delicate equipment to withstand the high temperatures used in steam sterilization. Equipment such as rigid telescopes could be steam sterilized for the first time.

The change to non-CFC metered dose inhalers

The first non-chlorofluorocarbon containing (non-CFC) metered dose inhaler (MDI) (i.e. albuterol, Airomir, 3M) has been approved for marketing in over 35 countries. It is hoped by the year 2000 most MDIs will use non-CFC propellants. By the year 2005 it is likely that CFC containing MDIs will no longer be available in developed countries. This article looks at the basis for this change and how it may affect medical practice.