Sustainability in Inhaled Drug Delivery

Asthma and chronic obstructive pulmonary disease (COPD) are amongst the most common chronic diseases worldwide, and are largely preventable by improving the quality of the air we breathe. The most commonly deployed treatment, the metered dose inhaler (MDI), uses hydrofluorocarbon propellants, which are powerful greenhouse gases that contribute disproportionately to the climate crisis. Alternative treatment strategies are required if we are to avoid contributing to the worst effects of climate change. These strategies include promoting non-pharmacological therapies like smoking cessation and pulmonary rehabilitation; empowering patients to gain better disease control through written management plans and encouraging preventer, rather than reliever therapies. Pharmacological strategies include: improving inhaler technique and spacer use; minimising propellant release by using smaller volume MDIs and simpler dosing regimes; dose counters to prevent waste; switching to low global warming potential inhalers; and inhaler recycling. There are also opportunities to improve disease control alongside reduced greenhouse gas emissions, including better matching of patients' devices to inhaler technique rather than defaulting to MDIs, stopping unnecessary inhaled steroids in COPD and maintenance and reliever therapy in asthma. New, lower global warming potential propellants are on the horizon, and their introduction could offer a golden opportunity to enhance MDIs usability and sustainability by making them refillable, integrating whistles to optimise inhalation technique, adding integrated caps, optimising materials for recycling and adding dose counters to all MDIs.

Use of Ozone-Depleting Substances. Direct final rule

The Food and Drug Administration (FDA, the Agency, or we) is amending its regulation on uses of ozone-depleting substances (ODSs), including chlorofluorocarbons (CFCs), to remove the designation for certain products as "essential uses" under the Clean Air Act. Essential-use products are exempt from the ban by FDA on the use of CFCs and other ODS propellants in FDA-regulated products and from the ban by the Environmental Protection Agency (EPA) on the use of ODSs in pressurized dispensers. The products that will no longer constitute an essential use are: Sterile aerosol talc administered intrapleurally by thoracoscopy for human use and metered-dose atropine sulfate aerosol human drugs administered by oral inhalation. FDA is taking this action because alternative products that do not use ODSs are now available and because these products are no longer being marketed in versions that contain ODSs.

The president speaks: prevention is best: lessons from protecting the ozone layer

The Montreal Protocol was signed 25 years ago. As a result, the irreversible destruction of the ozone layer was prevented. However, stratospheric ozone will not recover completely until 2060 and the consequent epidemic in skin cancer cases will persist until 2100. Many millions of patients with asthma and chronic obstructive pulmonary disease have safely switched from chlorofluorocarbon (CFC)-powered metered-dose inhalers (MDIs) to either hydrofluorocarbon (HFC) or DPIs. China will be the last country to phase out CFCs by 2016. HFCs are global warming gases which will be controlled in the near future. HFCs in MDIs may be phased out over the next 10-20 years.

Use of ozone-depleting substances; removal of essential-use designation (flunisolide, etc.). Final rule

The Food and Drug Administration (FDA), after consultation with the Environmental Protection Agency (EPA), is amending FDA's regulation on the use of ozone-depleting substances (ODSs) in self-pressurized containers to remove the essential-use designations for flunisolide, triamcinolone, metaproterenol, pirbuterol, albuterol and ipratropium in combination, cromolyn, and nedocromil used in oral pressurized metered-dose inhalers (MDIs). The Clean Air Act requires FDA, in consultation with the EPA, to determine whether an FDA-regulated product that releases an ODS is an essential use of the ODS. FDA has concluded that there are no substantial technical barriers to formulating flunisolide, triamcinolone, metaproterenol, pirbuterol, albuterol and ipratropium in combination, cromolyn, and nedocromil as products that do not release ODSs, and therefore they will no longer be essential uses of ODSs as of the effective dates of this rule. MDIs for these active moieties containing an ODS may not be marketed after the relevant effective date.

Short-term growth and adrenal function in children with asthma treated with inhaled beclomethasone dipropionate hydrofluoroalkane-134a

Inhaled beclomethasone dipropionate (BDP) with the propellant hydrofluoroalkane-134a (HFA) has been designed to be equivalent in terms of safety to chlorofluorocarbon (CFC)-formulated metered dose inhalers (MDI). The aim was to assess whether BDP HFA MDI 100 microg twice daily was equivalent to BDP CFC MDI 100 microg twice daily in terms of effects on short-term lower leg growth rate (LLGR) and measures of hypothalamic-pituitary-adrenal (HPA) function. The study consisted of a randomized double-blind cross-over trial with three active, a run-in and two wash-out periods each consisting of 2 wk. The place of study was a secondary referral outpatient clinic. The subjects involved were 14 boys and 10 girls with asthma, aged 7-12 yr. They were all administered BDP HFA 100 microg, BDP CFC 100 microg and 200 microg twice daily. The outcome measures included LLGR and 24-h urine-free cortisol (UFC) and total cortisol metabolites (TCM). Mean (SD) LLGR during run-in and BDP HFA 100 microg, BDP CFC 100 microg and 200 microg twice daily periods were 0.43 (0.23), 0.09 (0.29), 0.10 (0.45) and 0.08 (0.27) mm/wk. The one-sided 97.5% confidence interval for the difference in LLGR between BDP HFA 100 microg and BDP CFC 100 microg was 0.24, thus, below the predefined criterion of 0.20 mm/week. Inter-period comparisons of active treatments showed no differences between means of LLGR, UFC or TCM. Though non-inferiority between BDP HFA and CFC 100 microg twice daily in terms of effects on LLGR was not found, equivalence was suggested by comparisons of LLGR during run-in and active treatments and by HPA function measures.

Use of ozone-depleting substances; removal of essential-use designations. Final rule

The Food and Drug Administration (FDA) is amending its regulation on the use of ozone-depleting substances (ODSs) in self-pressurized containers to remove the essential-use designations for albuterol used in oral pressurized metered-dose inhalers (MDIs). Under the Clean Air Act, FDA, in consultation with the Environmental Protection Agency (EPA), is required to determine whether an FDA-regulated product that releases an ODS is an essential use of the ODS. Two albuterol MDIs that do not use an ODS have been marketed for more than 3 years. FDA has determined that the two non-ODS MDIs will be satisfactory alternatives to albuterol MDIs containing ODSs and is removing the essential-use designation for albuterol MDIs as of December 31, 2008. Albuterol MDIs containing an ODS cannot be marketed after this date.

Low incidence of paradoxical bronchoconstriction with bronchodilator drugs administered by Respimat Soft Mist inhaler: results of phase II single-dose crossover studies

BACKGROUND AND OBJECTIVES

Respimat Soft Mist Inhaler (SMI) is an innovative device that offers improved lung deposition and is an environmentally friendly alternative to conventional, chlorofluorocarbon-containing metered-dose inhalers (CFC-MDIs). The aqueous formulations of bronchodilator drugs administered from Respimat SMI contain low concentrations of ethylene diamine tetra-acetic acid (EDTA), a stabilising agent, and benzalkonium chloride (BAC), an antibacterial agent, both of which have been associated with bronchoconstriction when administered via nebulisers. The aim of this retrospective analysis was to compare the incidence of paradoxical bronchoconstriction with bronchodilator drugs administered via Respimat SMI or a CFC-MDI in patients with asthma or chronic obstructive pulmonary disease (COPD).

METHODS

Nine randomised, active- and/or placebo-controlled, double-blind, crossover studies, in which asthmatic and COPD patients (n = 444 and n = 216, respectively) received a beta(2)-agonist and/or anticholinergic or placebo via Respimat SMI or CFC-MDI, were included in the analysis. The incidence of conditions indicative of paradoxical bronchoconstriction were collated and divided into four categories: (1) 'bronchospasm'; (2) two or more of the following events: 'other respiratory adverse events', 'rescue medication use' or 'asymptomatic drop in forced expiratory volume in one second' (FEV(1)); (3) either 'rescue medication use' or 'other respiratory adverse event'; (4) 'asymptomatic drop in FEV(1)'.

RESULTS

The incidence of adverse events indicative of paradoxical bronchoconstriction was low in those patients using the Respimat SMI device, and similar to that seen in the CFC-MDI group. In addition, the incidence of adverse events indicative of paradoxical bronchoconstriction observed in the Respimat SMI group was similar for BAC + EDTA and BAC-only drug formulations.

CONCLUSIONS

These studies demonstrate that, due to the extremely low absolute amounts of BAC and EDTA delivered to the lungs by the device, Respimat SMI is safe with regard to paradoxical bronchoconstriction in patients with asthma or COPD.

Formula for a new foam

As the 2010 phaseout date for chlorofluorocarbons draws nearer, materials engineers are working to find replacements for these ozone-depleting chemicals in the production of plastics and other products. One team of engineers is focusing on a combination of two low-cost and environmentally benign substances--supercritical carbon dioxide and clay nanoparticles--to meet these needs. The result is a strong yet lightweight alternative that retains all the beneficial qualities of solid plastic.

UV-B damages eyes of barnacle larvae and impairs their photoresponses and settlement success

The impact of enhanced UV-B radiation on marine ecosystems due to ozone depletion has caused growing global concern. Barnacle larvae have evolved complex photoreceptors and elaborate phototactic behaviors, which enable them to identify suitable habitats for feeding and settlement. For the first time, we demonstrate that environmentally realistic levels of UV-B radiation can induce ocular damage in barnacle larvae, thereby impairing the phototactic behavior of naupliar larvae and reducing settlement success of cypris larvae. Significant disruptions of rhabdomeres (the photosensitive structures in which phototransduction takes place) occurred in the retinular cells of naupliar eyes when naupliar larvae were exposed to a UV-B dose of 7.2 kJ m(-2), and impairment was dependent upon dose rather than irradiance. Our experimental data also showed that phototaxis of nauplii was ca. 4 times more sensitive to UV-B than settlement of cyprids. Since barnacles play an important role in the function and structure of coastal systems worldwide, any impairment of phototactic and settlement behavior of the larvae would pose a significant threat to the sustainability of this ecologically important species. The fact that enhanced UV-B radiation can induce ocular damage and subsequent phototactic impairment in barnacle larvae suggests that UV-B may also cause similar damage to other zooplankton species.

What is the lesson from the unprecedented event over Antarctica in 2002?

Varotsos (2002a,b), suggested that both the smaller-sized ozone hole over Antarctica and its splitting in two holes in September 2002 occurred due to an unprecedented major sudden stratospheric warming caused by very strong planetary waves propagated in the southern hemisphere. Subsequently, a NASA press release of December 6, 2002, also reported the prevalence of very strong planetary waves in Antarctica. The aim of this Letter is to further discuss the morphology of the Antarctic ozone hole, to detect the causes that allowed the Antarctic stratosphere to exhibit this exceptional warming and to examine what it denotes about its mechanisms. Concerning the morphology, among the principal findings is that the ozone hole split occurred not only in the stratosphere but extended in the lower altitudes (upper troposphere). As to the causes of the major sudden stratospheric warming of 2002, a comparison with the previous warmings in Antarctica since 1964 is made. The smaller-sized Antarctic ozone hole of 2002 is approximately equal to that of 1988 when a strong sudden stratospheric warming occurred. If only the destruction of ozone by chlorofluorocarbons resulted in the delayed sudden stratospheric warmings in Antarctica, then the early sudden stratospheric warmings of 1988 and 2002 would not have occurred, since chlorofluorocarbon loading of the stratosphere has remained relatively stable in recent years. Furthermore, it appears that the El Nino characteristics in 1988 and 2002 are not similar.

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.

The role of CYP forms in the metabolism and metabolic activation of HCFCs and other halocarbons

The use of hydrochlorofluorocarbons (HCFCs) such as HCFC-123 (2,2-dichloro-1,1,1-trifluoroethane) and HCFC-141b (1,1-dichloro-1-fluoroethane) is becoming widespread as replacements for the ozone depleting chlorofluorocarbons. Hepatic activation of HCFC-123 or the unsaturated perchloroethylene through oxidative pathways leads to the formation of the electrophiles trifluoroacetyl chloride or trichloroacetyl chloride, respectively. These can react with epsilon-NH(2) functions of lysine in proteins and give rise to neoantigens. In the case of HCFC-123, this reaction is catalysed primarily by CYP2E1 and to a much lesser extent by the constitutive CYP2C19, CYP2B6 and CYP2C8. For perchloroethylene, the extent of activation is less and the reaction is catalysed primarily by the CYP2B family. While acute hepatotoxicity has been seen in humans exposed to HCFC-123 or halothane, little short- or long-term toxicity in rodents is observed. No immunological related toxicity of perchloroethylene has been reported in exposed humans. Long-term exposure of rats can lead to renal tubule carcinomas and in mice, hepatocellular carcinomas. These toxic reactions do not appear to be directly related to the formation of the putative trichloroacetyl chloride intermediate.

Selective inactivation of rat and bovine olfactory cytochrome P450 by three haloethanes

The effects of halothane, 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) and 1,1-dichloro-1-fluoroethane (HCFC-141b) on the P450 system in olfactory and hepatic microsomes of bovine and rat have been investigated. In the in vitro experiments, all three compounds decreased olfactory CYP-dependent activities in microsomes from both species, especially under anaerobic conditions, halothane showing the greatest effect. Hepatic activities were not affected. A selective olfactory CYP depletion was also observed in vivo after treatment with halothane, but not with HCFC-123 or HCFC-141b. A loss of olfactory ethoxycoumarin-O-deethylase activity was also found both in vitro and in vivo experiments, suggesting that a CYP2A isoform may be the main target of inactivation. The present results therefore suggest that CYP2A, the major isoform expressed in the olfactory tissue of mammals, may be particularly prone to catalyze the reductive metabolism of halothane both in anaerobic and aerobic conditions.

Neoantigen formation and clastogenic action of HCFC-123 and perchloroethylene in human MCL-5 cells

In this study, the metabolic activation of 2,2-dichloro-1,1,1-trifluoroethane (hydrochlorofluorocarbons-123, HCFC-123), halothane or 1,1-dichloro-1-fluoroethane (HCFC-141b) was compared to that of perchloroethylene, using lymphoblastoma derived cell lines expressing human CYP1A1, CYP1A2, CYP2E1, CYP2A6 and CYP3A4 (MCL-5 cells). A dose dependent increase in micronucleus formation was detected over a nominal concentration range of 0.05-2 mM for HCFC-123 and halothane, but this was not seen with HCFC-141b. No dose response for HCFC-123 was seen in a control cHo1 cell line not expressing this cytochrome P450's. Cell lines expressing individual human cytochrome P-450 (CYP) forms were also used to define the enzymes responsible for the clastogenic events and to investigate the formation of immunoreactive protein by microsomal fractions. It was shown that CYP2E1 or CYP2B6 catalysed the clastogenic response, but CYP2D6, CYP3A4, CYP1A2 or CYP1A1 all appeared to be inactive. The formation of neoantigenic trifluoroacetylated protein adducts by microsomal mixtures incubated with HCFC-123 and NADPH was catalysed primarily by CYP2E1 and to a lesser extent by CYP2C19, whereas, only trace levels of immunoreactive protein were seen with microsomes expressing CYP2B6 or CYP2C8. With perchloroethylene as a substrate, the extent of activation was low in comparison with HCFC-123, as judged by the absence of micronuclei formation in the MCL-5 cell line and the weak immunoreactivity of proteins following Western blotting. CYP1A2, CYP2B6 and CYP2C8 appeared to be responsible for perchloroethylene immunoreactivity and in contrast to the findings with the HCFC's, no activation of perchloroethylene by CYP2E1 could be detected. These results show that even though both saturated and unsaturated halocarbons can result in neoantigen formation, there is a marked difference in the specificity of the CYP enzymes involved in their metabolic activation.

Patients' opinions of CFC-free inhaler changeover in primary care

OBJECTIVE

To determine patient's opinions regarding the changeover from CFC containing to CFC-free salbutamol.

DESIGN

Patients receiving metered dose salbutamol inhaler therapy were identified and verbal consent was obtained before a semi-structured interview was performed. Setting An outpatient respiratory clinic within a busy teaching hospita.

MAIN OUTCOME MEASURES

Knowledge of CFC-free inhaler therapy and acceptance of change.

RESULTS

A total of 28 patients were identified of whom only eight (29%) had been changed to a CFC-free product. Six of these (75%) had received counselling from their GP or pharmacist regarding the change. Differences were reported by all of the patients who had been changed to a CFC-free inhaler with comments including difference in taste (6 patients), difference in feel (6), less effective (1) and more effective (1). Three patients preferred the CFC-free inhaler to their previous therapy. Although 13 out of the 20 patients who had not received a CFC-free inhaler stated they were happy with the potential changeover, 10 (80%) has concerns relating to effectiveness.

CONCLUSION

The majority of patients still receiving CFC inhalers were aware that the production of CFC-containing products had been restricted although they were unaware of the imminent changes that would take place regarding their inhaler therapy. However, the small sample size recruited in this study may mean that the results are unrepresentative of the CFC-free implementation process in the Grampian Health Board area as a whole. Nonetheless, in view of the differences experienced by patients who received CFC-free inhalers and the concerns stated about potential lack of efficacy by patients about to be changed over, it is essential that healthcare professionals provide advice on CFC-free inhalers to all patients.

Ipratropium bromide hydrofluoroalkane inhalation aerosol is safe and effective in patients with COPD

STUDY OBJECTIVE

To compare the efficacy and safety of ipratropium bromide reformulated with the chlorofluorocarbon (CFC)-free propellant hydrofluoroalkane (HFA)-134a (ipratropium bromide HFA) to that of the marketed ipratropium bromide inhalation aerosol (containing CFC) in patients with COPD.

DESIGN

This was a randomized, double-blind, parallel-group, placebo-controlled, multicenter trial. The primary efficacy parameter was acute bronchodilator response. The primary end points were peak change in FEV(1) from baseline and area under the response-time curve.

SETTING

Thirty-one clinical centers in the United States participated in this project.

PATIENTS

A total of 507 patients with moderate-to-severe COPD were randomized, and 444 patients completed the trial.

INTERVENTIONS

Twelve weeks of treatment four times daily with one of the following: ipratropium bromide HFA, 42 microg; ipratropium bromide HFA, 84 microg; HFA placebo; ipratropium bromide inhalation aerosol, 42 microg; or CFC placebo.

MEASUREMENTS AND RESULTS

Patients in all active treatment groups had significant bronchodilator responses as shown by increases in mean FEV(1) from baseline of at least 15%. Bronchodilator response in all active treatment groups was also significantly more than their respective placebo treatments based on FEV(1), area under the time-response curve from 0 to 6 h, and peak response. FVC results were similar to those seen with FEV(1). There were no significant differences in adverse events, laboratory findings, or ECG findings among the treatment groups.

CONCLUSIONS

Ipratropium bromide HFA, 42 and mgr;g, provided bronchodilation comparable to the marketed ipratropium bromide CFC, 42 and mgr;g, over 12 weeks of regular use.

Long-term safety and efficacy of a chlorofluorocarbon-free beclomethasone dipropionate extrafine aerosol

BACKGROUND

Beclomethasone dipropionate (BDP) extrafine aerosol, a newly developed pressurized metered dose inhaler (pMDI) with a hydrofluoroalkane-134a (HFA) propellant (HFA-BDP; Qvar, 3M Pharmaceuticals, St. Paul, MN), has been shown to be effective in controlling asthma symptoms at approximately half the daily dose of chlorofluorocarbon (CFC)-BDP.

OBJECTIVE

This study evaluated the long-term efficacy and safety of switching patients with asthma maintained on a stable dose of CFC-BDP pMDI to therapy with HFA-BDP pMDI at approximately half their previous daily dose of CFC-BDP.

METHODS

This was an open-label, randomized, parallel-group multicenter trial. Patients with at least a 6-month history of asthma whose symptoms were controlled on CFC-BDP, 400 to 1600 microg daily, during a 2-week run-in period were randomized in a 1:3 ratio to CFC-BDP at the same daily dose or HFA-BDP at approximately half the daily dose of CFC-BDP for 12 months.

RESULTS

A total of 473 patients were randomized: 354 to HFA-BDP, 119 to CFC-BDP. There were no statistically significant differences between groups in mean change from baseline in morning (AM) peak expiratory flow rate or forced expiratory volume in one second throughout the study. There were no consistent differences between treatment groups in individual asthma symptoms or daily beta2-agonist use during the study. There was an increase in the percentage of symptom-free days between baseline and month 12 in the HFA-BDP group (11.5%) and the CFC-BDP group (4.6%). No statistically significant differences in serum osteocalcin levels or adverse events were seen during the study or in AM plasma cortisol levels at month 12.

CONCLUSIONS

Asthma control was maintained in patients switched from a stable dose of CFC-BDP (400 to 1600 microg daily) to HFA-BDP at approximately half the CFC-BDP dose (200 to 800 microg daily), and was maintained over the next 12 months. HFA-BDP demonstrated a similar safety profile to CFC-BDP; there were no differences between the agents with regard to systemic effects.

Switching from Ventolin CFC to Ventolin HFA is well tolerated and effective in patients with asthma

BACKGROUND

Environmental imperatives to eliminate the use of chlorofluorocarbon (CFC) propellants in metered-dose inhalers have led to the development of metered-dose inhalers with the hydrofluoroalkane (HFA-134a) propellants.

OBJECTIVES

To evaluate the clinical effect of switching from Ventolin CFC to Ventolin HFA and to compare the efficacy and safety of Ventolin CFC, Ventolin HFA, and placebo in patients with asthma.

METHODS

Multicenter, double-blind, randomized safety and efficacy trial comparing regular use of Ventolin CFC versus Ventolin HFA versus placebo for 12 weeks in 313 patients with asthma aged 12 years and older who received Ventolin CFC during a 3-week run-in period.

RESULTS

Patients who were switched from Ventolin CFC to Ventolin HFA maintained pulmonary function and other measures of asthma control at levels comparable with run-in baseline. Serial pulmonary function testing demonstrated that both Ventolin treatments had significantly greater mean improvement in FEV1 over baseline than the placebo group at treatment day 1 and weeks 6 and 12 (P < .001). Both Ventolin groups had comparable pulmonary function at every visit. Predose FEV1 values were maintained or improved over time with all treatments. Treatments were well-tolerated. The adverse event profile for both Ventolin treatments was comparable with placebo. No clinically relevant effects on ECG, vital signs, or clinical laboratory tests were noted. Asthma exacerbation rates were 4% to 5% in the Ventolin groups and slightly higher (8%) in the placebo group.

CONCLUSIONS

Patients who were switched from Ventolin CFC to Ventolin HFA maintained comparable asthma control with a similar safety profile.

Comparable bronchodilation with hydrofluoroalkane-134a (HFA) albuterol and chlorofluorocarbons-11/12 (CFC) albuterol in children with asthma

This was an open-label, parallel group, randomized, age-stratified, multicenter study designed to compare the safety and efficacy of regular use of albuterol formulated in hydrofluoroalkane-134a (HFA albuterol) and albuterol formulated in chlorofluorocarbons-11/12 (CFC albuterol) in children with asthma. Children age 4-11 years using a short-acting inhaled beta2-agonist for 6 months to manage stable asthma, and with a prestudy forced expiratory volume in 1 sec (FEV1) of >50% predicted after withholding short-acting inhaled beta2-agonists for at least 6 hr, an increase in FEV1 > or = 12% within 30 min after two puffs of CFC albuterol, and the capability to comply with medication withholding requirements were eligible for study entry. After screening evaluation, patients entered a minimum 7-day run-in period. On study day 1 spirometry and a baseline 12-lead electrocardiogram (ECG) were performed, pulse and blood pressure were measured, and patients self-administered two puffs of their randomized study drug, either HFA albuterol or CFC albuterol. Serial spirometry was performed over 6 hr after study drug dosing. Pulse and blood pressure were measured just prior to each spirometry and a 12-lead ECG was performed at 60 min postdose. Patients took two puffs of their study drug four times a day for 4 weeks. At study week 4, study day 1 procedures were repeated. Patients maintained a daily diary of morning (A.M.) and evening (P.M.) peak expiratory flow (PEF), daytime asthma symptom scores, nighttime asthma sleep disturbance scores, and study drug use. Demographics and baseline characteristics of the 63 patients randomized to HFA albuterol (33) and CFC albuterol (30) were similar. No significant differences were found between the HFA albuterol and CFC albuterol treatment groups for any of the primary or secondary FEV1 efficacy variables either at study day 1 or study week 4. No significant differences were noted between treatment groups for A.M. and P.M. PEF, individual asthma symptom scores, nighttime asthma sleep disturbance scores, and rescue study drug use over the 4-week study. No significant differences were found between the two treatment groups for change from predose in heart rate, systolic and diastolic blood pressure, and 12-lead ECG intervals at either study day 1 or study week 4. Adverse event reporting was similar for the two treatment groups. In this study, with regular use of HFA albuterol in children with asthma, there was a similar safety profile and comparable bronchodilator efficacy as with CFC albuterol.

Clinical efficacy and safety of fluticasone propionate 1 mg per day administered via a HFA 134a pressurized metered dose inhaler to patients with moderate to severe asthma. International study group

This multi-national, double-blind, randomized, parallel-group study compared the efficacy and tolerability of fluticasone propionate 500 microg twice daily propelled either by the non-chlorofluorocarbon (CFC) propellant, hydrofluoroalkane (HFA) 134a, or the CFC propellants 11 and 12 used in the established pressurized metered dose inhaler (pMDI). The study period was 12 months and involved 412 subjects with moderate to severe asthma (HFA 134a pMDI: n = 203; CFC pMDI: n = 209). For the first 3 months, subjects kept a daily record card and attended the clinic every 4 weeks. Thereafter, they kept daily diaries for 2 weeks before each clinic assessment, which were performed at the end of 6, 9 and 12 months. Mean morning peak expiratory flow (PEF) increased during the first week in both treatment groups. By the end of week 12 the adjusted mean increase from baseline in morning PEF was 21 and 23 l min(-1) in the HFA 134a and CFC pMDI groups, respectively, and this increase was maintained throughout the 12-month study period. Similar improvements were detected in other diary card parameters and in clinic lung function measurements. The two groups were shown to be clinically equivalent in terms of all efficacy variables and there were no differences in tolerability. There were few reports of low serum cortisol levels during the 12-month study period, and serum cortisol levels were similar at baseline and after 12 weeks and 12 months of treatment in the two groups. In conclusion, the new HFA 134a fluticasone propionate pMDI is as effective and safe as the established CFC fluticasone propionate pMDI when used at a dosage of 1 mg day(-1).

Equivalence of salbutamol 200 microg four times daily propelled by propellants 11 and 12 or HFA 134a in mild to moderate asthmatics. Eastern European study group

The phasing out of chlorofluorocarbons (CFCs) requires the development of an alternative non-ozone depleting propellant for use in pressurized metered dose inhalers (pMDIs). The present study assessed the effects on tolerability and efficacy of a switch from the currently available formulation containing the CFC propellants 11 and 12 to an alternative non-CFC formulation using the propellant hydrofluoroalkane (HFA) 134a in patients with mild to moderate asthma. After a 4-week run-in period during which patients received salbutamol 200 microg four times daily from a CFC pMDI, 547 patients were randomized to 12 weeks of treatment with salbutamol 200 microg four times daily administered from either an HFA 134a pMDI (Ventolin CFC-free; 277 patients) or CFC pMDI (Ventolin, 270 patients). At the end of this period, all patients then received a further 4 weeks of treatment with the same dose of salbutamol via a CFC pMDI (run-out period). On the basis that high doses of beta2-agonists are known to increase heart rate, change in heart rate was selected as the primary outcome variable. Small increases in heart rate were observed during the treatment period and these changes were comparable in both groups; the 90% confidence interval for the treatment differences was within the predefined limits for clinical equivalence (+/- 10 beats min(-1)). The incidence of adverse events was similar in both groups and there were no reports of paradoxical bronchospasm. Furthermore, daily PEF measurements showed comparability in terms of lung function. Symptom scores and use of additional bronchodilator were also similar in both groups. These results demonstrate that salbutamol (800 microg day(-1)), formulated with HFA 134a is equivalent to the current CFC formulation in terms of tolerability and efficacy.

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

Images

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.