Protective effect of budesonide/formoterol compared with formoterol, salbutamol and placebo on repeated provocations with inhaled AMP in patients with asthma: a randomised, double-blind, cross-over study

Adenosine monophosphate is not superior to histamine for bronchial provocation test for assessment of asthma control and symptoms

BACKGROUND

Adenosine monophosphate (AMP) may reflect airway inflammation and hyperresponsiveness, but relationship between AMP and histamine (His, a conventional stimulus) bronchial provocation test (BPT) in asthma is not fully elucidated.

OBJECTIVES

To compare both BPTs and determine their utility in reflecting changes of asthmatic symptoms.

METHODS

BPTs were performed in a cross-over fashion, at 2-4 day intervals. Cumulative doses eliciting 20% FEV₁ fall (PD₂₀ FEV₁ ), diagnostic performance and adverse events (AEs) were compared. Patients with PD₂₀ FEV₁ lower than geometric mean were defined as responders, otherwise poor responders. Patients with uncontrolled and partly controlled asthma, who maintained their original inhaled corticosteroids therapy, underwent reassessment of airway responsiveness and asthmatic symptoms 3 and 6 months after.

RESULTS

Nineteen uncontrolled, 22 partly controlled and 19 controlled asthmatic patients and 24 healthy subjects were recruited. Lower PD₂₀ FEV₁ geometric means were associated with poorer asthma control in His-BPT (0.424 μmol vs 1.684 μmol vs 3.757 μmol), but not AMP-BPT (11.810 μmol vs 7.781 μmol vs 10.220 μmol). Both BPTs yielded similar overall diagnostic performance in asthma (area under curve: 0.842 in AMP-BPT vs 0.850 in His-BPT). AEs, including wheezing and tachypnea, were similar and mild. Ten patients with uncontrolled and 10 partly controlled asthma were followed-up. At months 3 and 6, we documented an increase in PD₂₀ FEV₁ -AMP and PD₂₀ FEV₁ -His, which did not correlate with reduction asthmatic symptom scores. This overall applied in responders and poor responders of AMP-BPT and His-BPT.

CONCLUSION

Despite higher screening capacity of well-controlled asthma, AMP-BPT confers similar diagnostic performance and safety with His-BPT. AMP-BPT might not preferentially reflect changes asthmatic symptoms.

Budesonide/formoterol maintenance and reliever therapy in asthma control: acute, dose-related effects and real-life effectiveness

BACKGROUND AND OBJECTIVE

The efficacy of budesonide/formoterol maintenance and reliever therapy (BFMRT) in asthma control is well documented in large randomized controlled trials. However, the acute reliever effects and real-life effectiveness are seldom reported.

METHODS

This multicenter trial enrolled steroid-naïve, symptomatic asthmatics with baseline exhaled nitric oxide (eNO) of ≥ 40 ppb. There were 120 eligible patients who were randomized and received a dose of inhaled budesonide/formoterol 320/9 μg (lower dose budesonide/formoterol), 640/18 μg (higher dose budesonide/formoterol (HDBF)), or terbutaline (TERB) 1 mg. Inflammatory cells and mediators in induced sputum, eNO and lung function were measured at baseline and 6 h (acute phase). Subsequently, all patients used BFMRT as real-life practice for 24 weeks (maintenance phase).

RESULTS

In the acute phase, the degree of post-treatment reduction in total eosinophil counts, interleukin-8 and matrix metalloproteinase-9 in induced sputum were significantly greater in group HDBF (vs TERB, P < 0.05). The increase in forced expiratory volume in first second (FEV1 ) in group HDBF was significantly higher (vs LDBF and TERB, P < 0.05) 3 h after dosing. In the maintenance phase, significant improvement of asthma control (presented by eNO, FEV1 and a five-item asthma control questionnaire) in real-life settings was observed at 4 weeks and sustained to the end of study. The rate of patients who followed scheduled visits declined over time (87% at week 4 and 42% at week 24).

CONCLUSIONS

Budesonide/formoterol as reliever exerts acute, dose-related anti-inflammatory effects and FEV1 improvement in symptomatic asthmatics. BFMRT is effective in asthma control. However, the decrease in long-term follow-up rate remains an issue to overcome in real-life settings.

Challenging the two-minute tidal breathing challenge test

BACKGROUND

In the adenosine 5'-monophosphate (AMP) bronchial challenge test, AMP is usually administered according to dosing protocols for methacholine. We investigated whether the 2-min tidal breathing challenge test for methacholine is applicable to AMP. Parameters known to affect nebulizer output were studied. Our aim was to determine whether control of additional parameters is needed for currently standardized protocols.

METHODS

The study was performed with the Sidestream nebulizer from the APS Pro Aerosol Provocation System (CareFusion Respiratory). The effects of AMP concentration, jet pressure, and suction flow rate on nebulizer output rate and aerosol droplet size distribution were determined.

RESULTS

The volume median diameter for water increased from 5.10 μm to 8.49 μm when the jet pressure was reduced to obtain the prescribed output rate of 0.13 mL/min. The output rate was increased when a suction flow rate was used to remove the aerosol. Increasing the AMP concentration resulted in smaller droplets and a lower output rate when a suction flow was applied.

CONCLUSIONS

The effects of AMP concentration on nebulizer performance may result in changes in the administered dose and site of deposition of AMP at dose escalation. All of the investigated parameters influence nebulizer performance, hence the outcome of a bronchial challenge test. Therefore, these parameters should not only be specified in challenge testing, but be actively controlled as well.

Rapid effects of extrafine beclomethasone dipropionate/formoterol fixed combination inhaler on airway inflammation and bronchoconstriction in asthma: a randomised controlled trial

BACKGROUND

The dose-dependent anti-inflammatory effects of a recent fixed combination of extrafine beclomethasone dipropionate/formoterol (BDP/F) were investigated using non-invasive markers of inflammation, exhaled nitric oxide (NO) and adenosine monophosphate (AMP) provocative challenge. The aim was to assess the onset of the anti-inflammatory action of low and high doses and evaluate the suitability of non-invasive assessments to demonstrate dose response.

METHODS

Steroid naïve adult out-patients with mild asthma, sensitive to AMP with baseline exhaled NO > 25 parts per billion entered a double-blind, placebo-controlled, 3-way, cross-over study. Patients were randomised to low dose (1 actuation) or high dose (4 actuations) extrafine BDP/F 100/6 μg, or placebo administered twice daily on Days 1 and 2 and once in the morning on Day 3 of each period. Exhaled NO was measured pre-dose on Day 1, then 2 and 4 hours post-administration on Day 3. The AMP challenge was performed 4 hours post-administration on Day 3 and forced expiratory volume in 1 second (FEV1, L) was measured from 0 to 4 hours post-dose on Day 1. Endpoints were NO at 2 and 4 hours, AMP challenge at 4 hours after the fifth dose on Day 3 and FEV1 area under the curve from 0 to 4 h post-dose on Day 1. Analysis of covariance was performed for NO and FEV1 and analysis of variance for AMP challenge.

RESULTS

Eighteen patients were randomised and completed the study. Exhaled NO was significantly lower for both doses of extrafine BDP/F versus placebo at 2 and 4 hours (high dose LS mean difference: -22.5 ppb, p < 0.0001 and -20.5 ppb, p < 0.0001; low dose: -14.1 ppb, p = 0.0006 and -12.1 ppb, p = 0.0043) with a significant dose response (p = 0.0342 and p = 0.0423). Likewise, AMP challenge revealed statistically significant differences between both doses of extrafine BDP/F and placebo (high dose LS mean difference: 4.8 mg/mL, p < 0.0001; low dose: 3.7 mg/mL, p < 0.0001), and a significant dose response (p = 0.0185). FEV1 was significantly improved versus placebo for both doses (high dose LS mean difference: 0.2 L, p = 0.0001; low dose: 0.2 L p = 0.0001), but without a significant dose response.

CONCLUSIONS

The fixed combination inhaler of extrafine BDP/F has early dose-dependent anti-inflammatory effects with a rapid onset of bronchodilatation in mild asthmatic patients.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01343745.