Effects of hydrocortisone on acute β-adrenoceptor blocker and histamine induced bronchoconstriction

Respiratory effect of beta-blockers in people with asthma and cardiovascular disease: population-based nested case control study

BACKGROUND

Cardiovascular disease (CVD) is a common comorbidity in people with asthma. However, safety concerns have caused heterogeneity in clinical guideline recommendations over the use of cardioselective beta-blockers in people with asthma and CVD, partly because risk in the general population has been poorly quantified. The aim of this study was to measure the risk of asthma exacerbations with beta-blockers prescribed to a general population with asthma and CVD.

METHODS

Linked data from the UK Clinical Practice Research Datalink was used to perform nested case-control studies among people with asthma and CVD matched on age, sex and calendar time. Adjusted incidence rate ratios (IRR) were calculated for the association between oral beta-blocker use and moderate asthma exacerbations (rescue oral steroids) or severe asthma exacerbations (hospitalisation or death) using conditional logistic regression.

RESULTS

The cohort consisted of 35,502 people identified with active asthma and CVD, of which 14.1% and 1.2% were prescribed cardioselective and non-selective beta-blockers, respectively, during follow-up. Cardioselective beta-blocker use was not associated with a significantly increased risk of moderate or severe asthma exacerbations. Consistent results were obtained following sensitivity analyses and a self-controlled case series approach. In contrast, non-selective beta-blockers were associated with a significantly increased risk of moderate asthma exacerbations when initiated at low to moderate doses (IRR 5.16, 95% CI 1.83-14.54, P = 0.002), and both moderate and severe exacerbations when prescribed chronically at high dose (IRR 2.68, 95% CI 1.08-6.64, P = 0.033 and IRR 12.11, 95% CI 1.02-144.11, P = 0.048, respectively).

CONCLUSIONS

Cardioselective beta-blockers prescribed to people with asthma and CVD were not associated with a significantly increased risk of moderate or severe asthma exacerbations and potentially could be used more widely when strongly indicated.

The inverse agonist propranolol confers no corticosteroid-sparing activity in mild-to-moderate persistent asthma

The murine asthma model shows that switching off airway β2 receptors with an inverse agonist may confer anti-inflammatory effects as well as corticosteroid-sparing activity. We have assessed for any corticosteroid-sparing effects of propranolol, an inverse agonist, added to low-dose inhaled corticosteroid (ICS) compared with higher dose ICS. A randomized double-blind placebo-controlled cross-over trial in mild-to-moderate persistent asthmatic patients was performed. After a run-in (2 weeks) on hydrofluoroalkane-beclometasone dipropionate (HFA-BDP) at 100 μg/day (HFA-BDP100), patients received randomized treatments (4 weeks) with propranolol at 80 mg/day plus HFA-BDP at 100 μg/day compared with placebo plus HFA-BDP at 400 μg/day (HFA-BDP400). Propranolol was up-titrated to 80 mg/day over the initial 2 weeks. Tiotropium was co-administered until 5 days before each histamine challenge (the primary outcome). Sixteen patients completed the study [mean age, 38 years; forced expiratory volume in 1 s (FEV1), 86.4%; histamine provocative concentration causing a 20% fall in FEV1 (PC20), 1.39 mg/ml; ICS dose, 406 μg/day]. Histamine PC20 was unchanged by adding propranolol to HFA-BDP100 compared with baseline (HFA-BDP100) {0.17 doubling dilution (dd) difference [95% confidence interval (CI): -0.58 to 0.92]}, but there was a significant improvement with HFA-BDP400 compared with both baseline [1.05 dd (95% CI: 0.43-1.66); P=0.02], and propranolol+HFA-BDP100 [0.88 dd (95% CI: 0.45-1.30); P=0.006]. Significant improvements were also observed with HFA-BDP400 for exhaled nitric oxide, blood eosinophils, serum eosinophilic cationic protein and asthma quality-of-life questionnaire symptoms compared with propranolol+HFA-BDP100. Salbutamol recovery post-challenge was partially blunted by propranolol (median prolongation 5 min; P=0.002). Domiciliary evening FEV1 also fell with propranolol+HFA-BDP100 [mean reduction from baseline 0.22 litres (95% CI: 0.10-0.34); P=0.012], whereas Asthma Control Questionnaire remained unchanged. In conclusion, the inverse agonist propranolol produced no improvements when given with low-dose ICS, whereas further significant improvements in airway hyper-responsiveness and inflammation were demonstrated with higher dose ICS. Thus, propranolol does not confer corticosteroid-sparing activity in persistent asthma.

Adverse respiratory effect of acute β-blocker exposure in asthma: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

β-Blockers are avoided in asthma over concerns regarding acute bronchoconstriction. Risk is greatest following acute exposure, including the potential for antagonism of β2-agonist rescue therapy.

METHODS

A systematic review of databases was performed to identify all randomized, blinded, placebo-controlled clinical trials evaluating acute β-blocker exposure in asthma. Effect estimates for changes in respiratory function, symptoms, and β2-agonist response were pooled using random effects meta-analysis with heterogeneity investigated.

RESULTS

Acute selective β-blockers in the doses given caused a mean change in FEV1 of −6.9% (95% CI, −8.5 to −5.2), a fall in FEV1 of ≥20% in one in eight patients (P=.03), symptoms affecting one in 33 patients (P=.18), and attenuation of concomitant β2-agonist response of −10.2% (95% CI, −14.0 to −6.4). Corresponding values for acute nonselective β-blockers in the doses given were −10.2% (95% CI, −14.7 to −5.6), one in nine patients (P=.02), one in 13 patients (P=.14), and −20.0% (95% CI, −29.4 to −10.7). Following investigation of heterogeneity, clear differences were found for celiprolol and labetalol. A dose-response relationship was demonstrated for selective β-blockers.

CONCLUSIONS

Selective β-blockers are better tolerated but not completely risk-free. Risk from acute exposure may be mitigated using the smallest dose possible and β-blockers with greater β1-selectivity. β-Blocker-induced bronchospasm responded partially to β2-agonists in the doses given with response blunted more by nonselective β-blockers than selective β-blockers. Use of β-blockers in asthma could possibly be based upon a risk assessment on an individual patient basis.

Effects of intravenous and oral β-blockade in persistent asthmatics controlled on inhaled corticosteroids

OBJECTIVE

Despite their benefits in the treatment of cardiovascular disease, β-blockers are seldom used to treat asthmatics. We assessed the safety and tolerability of acute dosing with esmolol and propranolol in patients with asthma.

DESIGN

Post-hoc analysis of a double blind, randomised, placebo controlled trial of β-blocker use in asthma.

PATIENTS

Mild-to-moderate asthmatics on inhaled corticosteroids.

INTERVENTIONS

Each participant underwent a 6-8 week dose titration of oral propranolol. A subgroup received an intravenous bolus dose of esmolol (0.5 mg/kg). Measurements were recorded pre- and post-esmolol and first dose exposure to 10 mg, 20 mg, and 80 mg of propranolol. Tiotropium was given concurrently with propranolol. Bronchoconstriction was reflected as a fall in forced expiratory volume in 1 s (FEV1) or increase in total airway resistance at 5 Hz (R5).

RESULTS

12 patients completed the trial. There were no adverse effects on FEV1% or R5% following intravenous esmolol. There were significant reductions at 2 min post-esmolol in heart rate (-4.7 beats/min (bpm), 95% CI -7.9 to -1.3 bpm; p=0.002) and systolic blood pressure (-5.9 mm Hg, 95% CI -11.4 to -0.4 mm Hg; p=0.03). No bronchoconstriction was seen during up titration following the first dose of 10 mg, 20 mg or 80 mg of propranolol in the presence of tiotropium. No difference in the asthma control questionnaire at 80 mg propranolol was seen versus placebo in the presence of tiotropium.

CONCLUSIONS

Intravenous esmolol was administered without any adverse effects on pulmonary function in selected, stable, mild-to-moderate asthmatics controlled on inhaled corticosteroids. Tiotropium prevented propranolol induced bronchoconstriction after acute dosing during up-titration to 80 mg with no adverse impact on asthma control.

Beta-blockers: friend or foe in asthma?

BACKGROUND AND AIM

Recently, β-blockers have been suggested as a potential maintenance treatment option for asthma. The aim of this review is to provide an overview of the current knowledge of the potential benefits and risks of β-blocker therapy for asthma.

METHOD

Systematic literature review.

RESULTS

No significant increase in the number of patients requiring rescue oral corticosteroid for an exacerbation of asthma has been observed after initiation of β-blocker treatment. Patients with mild to moderate reactive airway disease, probably both asthma and chronic obstructive pulmonary disease, may have a limited fall in forced expiratory volume in 1 second (FEV1) following single-dose administration of β-blocker, whereas no change in FEV1 has been reported following long-term administration. In a murine model of asthma, long-term administration of β-blockers resulted in a decrease in airway hyperresponsiveness, suggesting an anti-inflammatory effect. In keeping with this, long-term administration of a nonselective β-blocker to steroid-naïve asthma patients has shown a dose-dependent improvement in airway hyperresponsiveness, and either an asymptomatic fall in FEV1 or no significant change in FEV1. Furthermore, available studies show that bronchoconstriction induced by inhaled methacholine is reversed by salbutamol in patients on regular therapy with a β-blocker. On the other hand, a recent placebo-controlled trial of propranolol and tiotropium bromide added to inhaled corticosteroids revealed no effect on airway hyperresponsiveness and a small, not statistically significant, fall in FEV1 in patients classified as having mild to moderate asthma.

CONCLUSION

The available, although limited, evidence suggests that a dose-escalating model of β-blocker therapy to patients with asthma is well tolerated, does not induce acute bronchoconstriction, and, not least, may have beneficial effects on airway inflammation and airway hyperresponsiveness in some patients with asthma. Further studies addressing the potential role of β-blocker therapy for asthma are clearly needed, but careful selection of the target population is warranted.

Randomized placebo-controlled trial to evaluate chronic dosing effects of propranolol in asthma

RATIONALE

Unblinded studies have shown improvements in airway hyperresponsiveness with chronic nadolol in steroid-naive patients with asthma.

OBJECTIVES

To assess the effects of chronic nonselective β-blockade as add-on to inhaled corticosteroids (ICS) in patients with asthma.

METHODS

A double-blind randomized placebo-controlled crossover trial of propranolol in patients with mild-to-moderate asthma receiving ICS was performed. Participants underwent a 6- to 8-week dose titration of propranolol or placebo as tolerated to a maximum of 80 mg per day. Tiotropium was given for the first 4 to 6 weeks of each treatment period.

MEASUREMENTS AND MAIN RESULTS

Primary outcome was methacholine challenge. Secondary outcomes included histamine challenge, pulmonary function, mini-asthma quality of life questionnaire (mini-AQLQ), and asthma control questionnaire (ACQ). Eighteen patients completed (mean [SEM]): age, 36 (4) yr; FEV1%, 93 (2); ICS, 440 (66) μg/d. No significant difference was observed in methacholine or histamine challenge after exposure to propranolol versus placebo. For methacholine challenge, the doubling dilution difference was 0.04 (95% confidence interval [CI], -0.56 to 0.63), P = 0.89. Albuterol recovery at 20 minutes after histamine challenge was partially attenuated by propranolol versus placebo: FEV1% mean difference, 5.28 (95% CI, 2.54-8.01), P = 0.001. After chronic β-blockade there was a small worsening in FEV1 % predicted of 2.4% (95% CI, -0.1 to 4.8), P = 0.055. No difference was found for ACQ or mini-AQLQ.

CONCLUSIONS

This is the first placebo-controlled study to assess the effects of chronic nonselective β-blockade in asthma, showing no significant effect of propranolol compared with placebo on either methacholine or histamine airway hyperresponsiveness and no change in ACQ or AQLQ. Clinical trial registered with www.clinicaltrials.gov (NCT01074853).

Effects of respiratory motion on coronary wall MR imaging: a quantitative study of older adults

The aim of the present study is to assess the effects of respiratory motion on the image quality of two-dimensional (2D), free-breathing, black-blood coronary wall magnetic resonance (MR) imaging. This study was compliance with the HIPPA. With the approval of the institution review board, 230 asymptomatic participants, including 164 male patients (72.9 ± 4.4 years) and 66 female patients (72.4 ± 5.1 years), were recruited. Written informed consent was obtained. A 2D navigator (NAV)-gated, black-blood coronary wall MR imaging sequence was run on the left main artery, the left anterior descending artery and the right coronary artery. The drift of the location of the NAV and scan efficiency were compared between good (scored 2 or 3) and poor images (scored 1). Age, body weight, body weight index, heart rate, length of the rest period of cardiac motion, diaphragm excursion and breathing frequency were compared using a t test between the "successful" (having 2 or 3 good images) and "unsuccessful" cases (having 1 or 0 good images). A logistic regression model was applied to identify the contributors to good image quality. The drift of the NAV location and the scan efficiency were higher in the 411 good images compared with the 279 poor images. Minimal drift of the NAV location and low body weight were identified as independent predictors of good images after using a logistic regression model to adjust for multiple physiological and technical factors. The stability of respiratory motion significantly influences the image quality of 2D, free-breathing, black-blood coronary wall MR imaging.

Sensitivity of impulse oscillometry and spirometry in beta-blocker induced bronchoconstriction and beta-agonist bronchodilatation in asthma

BACKGROUND

Impulse oscillometry (IOS) provides an alternative method of assessing pulmonary function to conventional spirometry.

OBJECTIVE

To compare the sensitivities of IOS and spirometry in assessing bronchoconstriction to propranolol and bronchodilation with salbutamol.

METHODS

A post-hoc analysis of a randomized placebo-controlled crossover study was performed. Patients with mild-to-moderate persistent stable asthma taking 1,000 μg/day or less beclomethasone dipropionate equivalent received 10 or 20 mg of oral propranolol followed by histamine challenge, with recovery to nebulized salbutamol (5 mg). Spirometry and IOS were measured before and 2 hours after beta-blocker, post histamine, and 20 minutes post-salbutamol. Pre versus post percent change (95%CI) values were compared, and standardized response means (SRM) were calculated to assess the "signal to noise" of each test.

RESULTS

Thirteen participants (mean age, 34 years) completed the protocol. Eleven participants received 20 mg of propranolol; 2 received 10 mg, because this dose caused more than 10% decrease in forced expiratory volume in 1 second (FEV(1)) on the test-dose algorithm. All IOS indices (R5, R5-R20, AX, RF) showed significant worsening of airways resistance or reactance to propranolol. FEV(1) but not FEF25-75 showed significant deterioration after beta-blocker (mean percent change, 4.6% and 6.2%). The magnitude of change was consistently higher for parameters of IOS, with the largest change being observed with R5 and RF (mean percent change, 30.8% and 39.4%). The SRMs for IOS outcomes were better than for spirometry. All measures of lung function showed significant bronchodilator response, with the best SRMs seen in R5 and RF.

CONCLUSION

IOS is a more sensitive response outcome than spirometry with respect to bronchoconstriction to oral propranolol and bronchodilatation after salbutamol in patients with mild to moderate asthma.