Ventilatory effects of beta 1-receptor-selective blockade with bisoprolol and metoprolol in asthmatic patients

Cardioselective beta-blocker use in patients with reversible airway disease

BACKGROUND

Beta-blocker therapy has mortality benefit in patients with hypertension, heart failure and coronary artery disease, as well as during the perioperative period. These drugs have traditionally been considered contraindicated in patients with reversible airway disease.

OBJECTIVES

To assess the effect of cardioselective beta-blockers on respiratory function of patients with reversible airway disease. Reversible airway disease was defined as asthma or chronic obstructive pulmonary disease with a reversible obstructive component.

SEARCH STRATEGY

A comprehensive search of EMBASE, MEDLINE and CINAHL was performed using the Cochrane Airways Group registry to identify randomized blinded placebo-controlled trials from 1966 to February, 2000. The search was completed using the terms: asthma*, bronchial hyperreactivity*, respiratory sounds*, wheez*, obstructive lung disease* or obstructive airway disease*, and adrenergic antagonist*, sympatholytic* or adrenergic receptor block*. We did not exclude trials on the basis of language.

SELECTION CRITERIA

Randomized, blinded, placebo-controlled trials of single dose or longer duration that studied the effects of cardioselective beta-blockers on the forced expiratory volume in 1 second (FEV1), symptoms and use of short-acting inhaled beta-agonists, in patients with reversible airway disease. Reversible airway disease was documented by response to methacholine challenge, by an increase in FEV1 of at least 15% to beta-agonist administration, or the presence of asthma as defined by the American Thoracic Society.

DATA COLLECTION AND ANALYSIS

Two independent reviewers extracted data from the selected articles, reconciling differences by consensus. Cardioselective beta-blockers were divided into 2 groups, those with or without intrinsic sympathomimetic activity (ISA). Two interventions studied were the administration of beta-blocker, given either as a single dose or for longer duration, and the use of beta-agonist given after the study drug.

MAIN RESULTS

Nineteen studies for single-dose treatment and 10 for treatment of longer duration met selection criteria. The patients had mild-moderate airways obstruction. For cardioselective beta-blockers taken as a group, administration of a single dose was associated with a 7.98% (CI, 6.19 to 9.77%) reduction in FEV1, but with a 13.16% (CI, 10.76 to 15.56%) increase in beta-agonist response, as compared to placebo. There was no increase in symptoms. After treatment lasting a few days to a few weeks, there was no decrement in FEV1 compared to placebo and no increase in symptoms or inhaler use. Regular use of cardioselective beta-blockers without ISA produced a 13.13% (CI, 5.97 to 20.30) increase in beta-agonist response compared to placebo, a response not seen with beta-blockers containing ISA (-0.60% [CI, -11.7 to +10.5%]).

REVIEWER'S CONCLUSIONS

Cardioselective beta-blockers, given to patients with mild-moderate reversible airway disease, do not produce clinically significant adverse respiratory effects in the short term. It is not possible to comment on their effects in patient with more severe or less reversible disease, or on their effect on the frequency or severity of acute exacerbations. Given their demonstrated benefit in conditions such as heart failure, coronary artery disease and hypertension, cardioselective beta-blockers should not be withheld from patients with mild-moderate reversible airway disease.

Bisoprolol: is this just another beta-blocker for hypertension or angina?

OBJECTIVE

To review the pharmacology, pharmacokinetics, and clinical experience with bisoprolol and make recommendations regarding its potential clinical usefulness, as well as considerations for formulary inclusion.

DATA SOURCES

Reference citations were sought from Index Medicus and Science Citation Index. Data were collected from abstracts and articles describing experimental studies or blind clinical trials.

STUDY SELECTION

Studies designed in a randomized, blind, and placebo-controlled manner were emphasized. Studies also were included if bisoprolol was evaluated comparatively with other agents in a randomized, blind fashion.

DATA EXTRACTION

Data from human studies published in English were evaluated. Studies were assessed by sample size and the clarity of descriptions of methods and results.

DATA SYNTHESIS

Bisoprolol reduces systolic and diastolic blood pressures in patients with hypertension for a 24-hour dosing interval and is associated with beneficial hemodynamic effects in patients with myocardial ischemia. It is devoid of intrinsic sympathomimetic activity and membrane-stabilizing effects at therapeutic dosages. In patients with hypertension, bisoprolol diminishes plasma renin activity, platelet aggregation, effective renal plasma flow, and creatinine clearance. Bisoprolol has minimal effects on glucose tolerance and plasma lipid profiles. Monotherapy with bisoprolol is as effective as with atenolol, nitrendipine, or nifedipine. Low-dose combination therapy with hydrochlorothiazide is at least as effective as either bisoprolol or hydrochlorothiazide alone. Preliminary experience in the management of angina pectoris suggests that bisoprolol is at least as efficacious as atenolol or verapamil. Thus far, reported adverse effects are similar to those of other beta-blockers. No clinically important drug interactions have been reported at this time.

Bisoprolol, a once-a-day beta-blocking agent for patients with mild to moderate hypertension

The 24-h blood pressure control of bisoprolol, a new beta-selective, beta-blocking agent, was studied in 240 mild to moderate hypertensive patients in this 4-week, randomized, double-blind, placebo-controlled trial. A once-daily dosing schedule was evaluated by comparing bisoprolol's antihypertensive effectivness and safety at 24 h postdose and 3 h postdose, the latter time intended to correspond to peak effectiveness. Results from this trial demonstrated the antihypertensive effectiveness of once-daily bisprolol at doses ranging from 5-20 mg. Mean reductions from baseline diastolic blood pressure, measured 24 h postdose, were 6.3, 8.8, and 10.1 mmHg for patients receiving bisoprolol 5, 10, and 20 mg, respectively, compared with 1.6 mmHg for placebo-treated patients (p < 0.01); mean reductions from baseline systolic blood pressure for the bisoprolol groups were 8.6, 8.6, and 10.9 mmHg, respectively, versus 3.3 mmHg for placebo (p < or = 0.01); and mean reductions from baseline heart rate for the bisoprolol groups were 5.1, 7.1, and 10.2 beats/min, respectively, compared with a 0.9 beats/min increase in heart rate for the placebo group (p < 0.01). The response rates for bisoprolol-treated patients ranged from 47 to 70% compared with 18% for patients on placebo (p < 0.01). Antihypertensive effects were dose-related and sustained over the 24-h dosing interval. Near maximal antihypertensive effects were achieved within 1 week of initiation of therapy with bisoprolol and were sustained over the course of the trial.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic evaluation of bisoprolol after coronary artery surgery in patients with altered left ventricular function

Bisoprolol is a new cardioselective beta1 adrenergic blocking agent without intrinsic sympathomimetic activity but with minimal effects on myocardial contractility. Bisoprolol was compared to propranolol in 24 patients after cardiac surgery for coronary artery bypass graft (CABG). Each patient had been treated preoperatively with beta-blocking agents and had a cineangiographic left ventricular ejection fraction between 35% and 55%. Patients were randomized to receive orally either 10 mg of propranolol three times a day or 5 mg of bisoprolol once a day. Both drugs resulted in a significant and similar decrease in heart rate. This was associated with significant decreases in cardiac index, stroke index, and thermodilution right ventricular ejection fraction 6 hours after administration of propranolol, but not after bisoprolol. Systolic function measured by Doppler techniques significantly increased in the 10 postoperative days in patients under bisoprolol but not significantly after propranolol. Each drug was well tolerated during the 10 postoperative days, and the recovery was uneventful in each patient. These results indicate that in patients with altered systolic function after CABG, bisoprolol is susceptible to reduce heart rate with less cardiovascular alteration than propranolol.

Comparative beta-adrenoceptor blocking effects of propranolol, bisoprolol, atenolol, acebutolol and diacetolol on the human isolated bronchus

Five beta-adrenoceptor blockers, propranolol, acebutolol, diacebutolol, atenolol and bisoprolol, were tested for their antagonistic effect against isoprenaline on human isolated bronchi. The results showed (1) that only propranolol exerted a competitive antagonistic effect against isoprenaline (pA2 = 9.40 +/- 0.22, n = 7) whereas the other drugs did not, and (2) that, in the presence of beta-adrenoceptor blockers in the plasma concentrations reported after a single usual therapeutic dose, the doses of isoprenaline giving the same bronchodilator effect must be multiplied by 32.6, 5.51, 4.63, 2.82 and 1.95 respectively with propranolol, diacetolol, acebutolol, atenolol, and bisoprolol. It was concluded that (1) atenolol and bisoprolol were the least potent drugs at bronchial level in therapeutic plasma concentrations and (2) that tests performed on the human isolated bronchus might be a useful screening procedure for new drugs with potential activity on the airways.

Comparative effects of bisoprolol and acebutolol in smokers with airway obstruction

1. The effects of single oral doses of 10 mg bisoprolol and 400 mg acebutolol on respiratory function were studied in nine smokers with airway obstruction in a double-blind, placebo-controlled experiment. 2. The effects of the drugs were assessed by measuring specific airway conductance (sGaw) for 3 h after their administration and by studying their interaction with the bronchodilator response to inhaled salbutamol. 3. sGaw did not change for 3 h after bisoprolol or acebutolol administration. The bronchodilator response to inhaled salbutamol was not affected by bisoprolol but significantly reduced by acebutolol (P less than 0.05 vs placebo). 4. Under these conditions, bisoprolol behaves like a selective beta 1-adrenoceptor antagonist but acebutolol exhibits less beta 1-adrenoceptor selectivity.

A comparative study on the ventilatory and haemodynamic effects of xamoterol and atenolol in asthmatic patients

The effects of single oral doses of atenolol 50 mg and xamoterol 200 mg (a recently developed partial beta 1-adrenoceptor agonist) on lung function, heart rate and blood pressure were investigated in 11 patients with asthma. Xamoterol caused a significant increase in heart rate and systolic blood pressure, which changes are consistent with the partial beta 1-adrenoceptor agonist activity of this drug. Atenolol induced a significant decrease in FEV1 and the forced vital capacity (FVC); there was a non-significant change in FEV1 and FVC after xamoterol. There was no significant difference between the effects of atenolol and xamoterol of FEV1 and FVC. Bronchospasm induced by atenolol 50 mg and xamoterol 200 mg was completely reversed by inhalation of the beta 2-adrenoceptor agonist terbutaline to a cumulative dose of 4.0 mg.

Pharmacodynamic profile of bisoprolol, a new beta 1-selective adrenoceptor antagonist

The pharmacodynamic profile of bisoprolol, a new beta 1-selective adrenoceptor antagonist, was investigated in four independent studies including 36 healthy male volunteers. Using the model of exercise-induced tachycardia (ET) the beta-adrenoceptor blocking properties of bisoprolol (2.5-40 mg) were examined in comparison to metoprolol (50 and 100 mg), propranolol (40 and 80 mg) and atenolol (50 and 100 mg). The maximal reduction of ET was achieved between 1 and 4 h following single oral administration. The dose-response relationship using individual maximal reduction of ET showed, on a molar basis, that bisoprolol is about 5, 7 and 10 times more effective than propranolol, atenolol and metoprolol, respectively. In the model of insulin-induced hypoglycaemia bisoprolol behaved as a beta 1-selective adrenoceptor antagonist. There was a good correlation (r = 0.94) between the log bisoprolol concentration and the reduction in exercise-induced tachycardia. Bisoprolol is a potent new cardioselective beta-adrenoceptor antagonist with a competitive action at beta 1-adrenoceptors.

Effects of single oral doses of bisoprolol and atenolol on airway function in nonasthmatic chronic obstructive lung disease and angina pectoris

A randomized, placebo-controlled, double-blind crossover investigation in 12 patients with non-asthmatic chronic obstructive lung disease and co-existing stable angina pectoris was done to compare two beta 1-selective adrenoceptor blocking agents, atenolol 100 mg and bisoprolol 20 mg. Systolic and diastolic blood pressures (SBP, DBP), heart rate (HR) as well as airway resistance (AWR, and less frequently forced expiratory volume in 1 s (FEV1) and intrathoracic gas volume (ITGV) were measured in the sitting position before and at various times up to 24 h after drug intake. During the first 4 h both beta-blockers produced a significant reduction in HR in comparison to placebo (p less than 0.01). Atenolol 100 mg significantly increased AWR relative to placebo and bisoprolol (p less than 0.05). After 24 h, a significant reduction in HR (p less than 0.01) could only be demonstrated after bisoprolol, whereas atenolol alone led to a significant elevation in AWR relative to placebo and bisoprolol (p less than 0.05) at that time. It is concluded that bisoprolol appears to have a high degree of beta 1-selectivity, thus providing a wide split between beta 1- and beta 2-adrenoceptor blockade. Bisoprolol in its therapeutic dose range is expected to be relatively safe as regards bronchoconstriction in patients suffering both from hypertension and/or angina pectoris and chronic obstructive lung disease.