Short-term cardiovascular effects of salmeterol

Effect of long-acting β2-agonists olodaterol and formoterol on heart rate and blood pressure in chronic obstructive pulmonary disease patients

BACKGROUND

Cardiovascular comorbidities are common in chronic obstructive pulmonary disease (COPD), and elevated heart rate reflects increased cardiovascular risk over time, which is associated with unfavourable neurohumoral activation. Long-acting β₂-agonists (LABAs) are established treatments in COPD, but potentially increase heart rate. We report a post hoc pooled analysis of the effect of olodaterol (5 or 10 μg) or formoterol (12 μg) on heart rate and blood pressure (BP) in Global Initiative for Chronic Obstructive Lung Disease Stage 2-4 COPD patients.

METHODS

Four randomised, double-blind, placebo-controlled, Phase III studies were analysed. Changes in heart rate and systolic/diastolic BP were measured before and after dosing with the study medication at each visit.

RESULTS

At each study visit, the increase in pre-dose heart rate was numerically lower with both LABAs compared with placebo. Systolic and diastolic BP were decreased with all treatments. Short-term (pre-dose to 40 min post-dose) effects of drug administration on heart rate were small and similar for all treatment arms (between -3 and +1 beats per minute).

CONCLUSION

Heart rate and BP were not adversely influenced in this study involving long-term administration of olodaterol or formoterol in patients with moderate-to-severe COPD. This supports the cardiovascular safety of LABAs in COPD maintenance treatment.

Medication and dosage considerations in the prophylaxis and treatment of high-altitude illness

With increasing numbers of people traveling to high altitude for work or pleasure, there is a reasonable chance that many of these travelers have preexisting medical conditions or are receiving various medications at the time of their sojourn. As with all travelers to high altitude, they are at risk for altitude illnesses such as acute mountain sickness, high-altitude cerebral edema, and high-altitude pulmonary edema. While there are clear recommendations for pharmacologic measures to prevent or treat these illnesses, these recommendations are oriented toward healthy individuals and do not take into account the presence of preexisting medical conditions. In this review, we consider how the choice and dose of the medications used in the management of altitude illness-acetazolamide, dexamethasone, nifedipine, tadalafil, sildenafil, and salmeterol-are affected by a patient's underlying medical conditions. We discuss the indications and current dosing recommendations for individuals without underlying disease, and then consider how drug selection or dosing regimens will be affected by the presence of renal insufficiency, hepatic insufficiency, other important medical conditions, and the potential for serious drug interactions. We include comments about interactions with antimalarial medications and antibiotics used in the treatment of traveler's diarrhea, as well as the safety of use during pregnancy. By giving these issues adequate consideration, clinicians can increase the chances that properly evaluated patients with underlying medical conditions will enjoy a safe trip to high altitude.

β-2 Adrenergic Receptor Diplotype Defines a Subset of Salt-Sensitive Hypertension

Two genetic variants of the beta-2 adrenergic receptor, 46G>A and 79C>G, affect agonist-mediated receptor downregulation and vascular reactivity. We determined whether these variants were associated with hypertension, per se, blood pressure response to dietary sodium, 2 forms of salt-sensitive hypertension (low renin and nonmodulation), and the activity of the renin-angiotensin-aldosterone system. Included are 280 hypertensive and 65 normotensive white subjects who had the 2 beta-2 adrenergic receptor genotypes available. Of all subjects, 171 hypertensive and 48 normotensive subjects had complete data for intermediate phenotyping and blood pressure evaluation on high- and low-sodium balance. The beta-2 adrenergic receptor variants were not associated with hypertension per se. However, among hypertensive subjects, the change (from low to high sodium balance) in mean arterial pressure differed significantly by genotype and by diplotype. Compared with all of the other diplotypes combined, 46AA/79CC was associated with a greater change in blood pressure. Furthermore, this diplotype was associated with low-renin (LR) hypertension (identifying 32% of the LR hypertensives), higher plasma aldosterone, and lower plasma renin and serum potassium levels. In conclusion, the 46AA/79CC diplotype is associated with greater blood pressure response to dietary sodium and higher odds of LR hypertension. We propose that the mechanism for the observed association is inadequate suppression of aldosterone with salt intake, implicating the beta-2 adrenergic receptor in the regulation of aldosterone secretion. This hypothesis was confirmed in isolated glomerulosa cells, where beta-2 adrenergic receptor stimulation increased aldosterone secretion, whereas blockade reduced the stimulated aldosterone response. Importantly, this association could only be detected with an intermediate and not a distant phenotype.

Inhaled beta2-adrenoceptor agonists: cardiovascular safety in patients with obstructive lung disease

Although large surveys have documented the favourable safety profile of beta(2)-adrenoceptor agonists (beta(2)-agonists) and, above all, that of the long-acting agents, the presence in the literature of reports of adverse cardiovascular events in patients with obstructive airway disease must induce physicians to consider this eventuality. The coexistence of beta(1)- and beta(2)-adrenoceptors in the heart clearly indicates that beta(2)-agonists do have some effect on the heart, even when they are highly selective. It should also be taken into account that the beta(2)-agonists utilised in clinical practice have differing selectivities and potencies. beta(2)-agonist use has, in effect, been associated with an increased risk of myocardial infarction, congestive heart failure, cardiac arrest and sudden cardiac death. Moreover, patients who have either asthma or chronic obstructive pulmonary disease may be at increased risk of cardiovascular complications because these diseases amplify the impact of these agents on the heart and, unfortunately, are a confounding factor when the impact of beta(2)-agonists on the heart is evaluated. Whatever the case may be, this effect is of particular concern for those patients with underlying cardiac conditions. Therefore, beta(2)-agonists must always be used with caution in patients with cardiopathies because these agents may precipitate the concomitant cardiac disease.

Benefit-risk assessment of long-acting beta2-agonists in asthma

The use of a regular long-acting beta2-adrenoceptor agonists (beta2-agonists; LABA) is now established in asthma guidelines as the preferred option for second-line controller therapy in addition to inhaled corticosteroids. This has been driven by data showing beneficial effects of LABAs on exacerbation rates, in turn suggesting a putative corticosteroid-sparing effect. As LABAs are devoid of any clinically meaningful anti-inflammatory activity in vivo, their effects on exacerbations are presumably due to a diurnal stabilising effect on airway smooth muscle. LABAs have marked effects on symptoms and lung function, and this may make it difficult to assess anti-inflammatory control with inhaled corticosteroids when used in a combination inhaler such as fluticasone propionate/salmeterol or budesonide/formoterol. The use of fixed-dose combination inhalers is in many respects counter-intuitive to conventional teaching regarding flexible dosage titration with inhaled corticosteroids. It would therefore seem prudent first to gain optimal control of inflammation with inhaled corticosteroids before considering adding a LABA. Increasing the dosage of inhaled corticosteroids will have a relatively greater effect on exacerbations than on symptoms and lung function, whereas the converse applies when adding a LABA. Another option is to add a leukotriene receptor antagonist, which confers additional anti-inflammatory activity and is as effective on exacerbations as adding a LABA. Despite in vitro and ex vivo data showing a ligand-independent effect of LABAs on glucocorticoid receptor activation, clinical data do not indicate any relevant synergy between LABAs and inhaled corticosteroids when used together in the same inhaler. In particular, there is no evidence of potentiation by LABAs of the in vivo anti-inflammatory activity of inhaled corticosteroids that would suggest any genuine corticosteroid-sparing activity. Nonetheless, the data support the additive effects of inhaled corticosteroids and LABAs when used together due to their separate effects on inflammation and smooth muscle, respectively. Tolerance with LABAs is a predictable pharmacological phenomenon that occurs despite concomitant therapy with inhaled corticosteroids. Moreover, cross-tolerance also develops to short-acting beta2-agonists used for protection against bronchoconstrictor stimuli as a result of LABA-induced down-regulation, desensitisation and prolonged occupancy of beta2-adrenoceptors. The exact role of beta2-adrenoceptor polymorphism in determining tolerance with LABAs requires further prospective clinical studies evaluating long-term effects on outcomes such as exacerbations in patients with relevant genotypes and haplotypes. The next decade will provide challenging issues for clinicians with respect to defining further the role of LABAs as add-on controller therapy, particularly in evaluating the long-term effects of combination inhalers on inflammatory outcomes and airway remodelling.

Long-acting inhaled beta 2-agonists for stable COPD

OBJECTIVE

To describe the pathogenesis of chronic obstructive pulmonary disease (COPD) and mechanisms of benefit, formulations available, drug costs, pharmacokinetic profiles, and pertinent clinical studies for long-acting beta(2)-agonists.

DATA SOURCES

A MEDLINE search was conducted from July 1966 through October 2002.

STUDY SELECTION AND DATA EXTRACTION

Pertinent articles related to COPD and long-acting beta(2)-agonists.

DATA SYNTHESIS

The incidence and subsequent morbidity and mortality of COPD have increased during the last 4 decades, prompting worldwide initiatives to formulate guidelines to decrease the burden of this disease. COPD is a progressive, irreversible disease state characterized by chronic cough, dyspnea, sputum production, and wheezing, in which no medication has been shown to decrease mortality, excluding oxygen supplementation. Bronchodilators have been a mainstay of COPD treatment through their ability to work by both smooth- and non-smooth-muscle mechanisms. Long-acting beta(2)-agonists (i.e., formoterol, salmeterol) dosed twice daily provide more convenient dosing than 4-times-daily regimens of traditional short-acting bronchodilators. Both formoterol and salmeterol have acceptable adverse event profiles when used at recommended doses. There have been no direct clinical outcome studies comparing formoterol and salmeterol, but both have shown some benefits over ipratropium and theophylline in improving the symptoms, spirometric indices, exacerbations, and quality of life of patients with COPD.

CONCLUSIONS

Based on current evidence, long-acting beta(2)-agonists are acceptable first-line agents for patients with COPD.

Adverse effects of beta-agonists

Short-acting beta-adrenergic receptor agonists have pharmacologically predictable dose-related and potency-related adverse effects, including tachycardia and tremor, and they also affect serum potassium and glucose. These effects all show tolerance with continued exposure. The potential for arrhythmia is increased by comorbidity and hypoxemia. Nonpharmacologically predictable effects include airway hyperresponsiveness to nonspecific and specific stimuli, including allergen and exercise, and increased airway inflammation. Genetic variants of the beta-adrenergic receptor alter susceptibility to adverse effects of beta-agonists on airway function. The impact of the enantiomers of beta-agonists on adverse effects remains unclear. The two epidemics of asthma death among young people were temporally associated with introduction of potent short-acting beta-agonists (isoproterenol and fenoterol) and appear to be related to adverse effects of these drugs on airway function and airway hyperresponsiveness rather than to cardiotoxicity. Compared with short-acting agents, long-acting beta-agonists show similar but less pronounced pharmacologically predictable effects, and they have not been shown to increase airway hyperresponsiveness in adults. Postmarketing surveillance studies have not suggested significant adverse effects of long-acting beta-agonists on morbidity and mortality.

The effect of inhaled beta2-agonists on clinical outcomes in chronic obstructive pulmonary disease

The major clinical outcomes measured in evaluating the responses to pharmacotherapy in patients with chronic obstructive pulmonary disease (COPD) include the severity of dyspnea, exercise capacity, exacerbations, and health status. Various studies have demonstrated that testing for acute bronchodilator reversibility in the pulmonary function laboratory does not predict the clinical responses to a trial of bronchodilator therapy in patients with COPD. Separate studies have shown that inhaled albuterol, both a single dose (300 microg) and 2 weeks of therapy (200 microg/4x/day), reduces dyspnea. There is more published information available about the effects of long-acting (>/=12 hours' duration of action) inhaled beta(2)-agonists because of greater interest in considering clinical outcomes at the time of drug testing. In one randomized clinical trial, formoterol reduced symptoms (as recorded in a home diary) and improved health status. Nine clinical studies have examined the effects of salmeterol on clinical outcomes. Salmeterol reduced the perception of breathlessness (in 6 of 9 studies) and improved health status (in 3 of 4 studies). These results collectively demonstrate that long-acting inhaled beta(2)-agonists not only relax bronchial smooth muscle but also provide important clinical benefits in symptomatic patients with COPD.

Addition of an extra dose of salmeterol Diskus to conventional dose of salmeterol Diskus in patients with COPD

Patients experiencing dyspnoea can request an additional dose of salmeterol during the dose interval for the control of their symptoms, although under treatment with salmeterol. In this study we have explored the effects on respiratory function of an additive dose of salmeterol Diskus in 15 chronic obstructive pulmonary disease (COPD) patients in regular treatment with a conventional dose of 50 microg salmeterol. On two different days, patients inhaled 50 microg Diskus. After 240 min, they inhaled additional 50 microg salmeterol Diskus (salmeterol arm) or placebo Diskus (placebo arm). Lung function was controlled before first drug administration and 0.5, 1, 2, 3, 4, 4.5, 6, 8, 10, and 12 h thereafter. The mean (95% CI) peak increase in FEV1 from baseline was reached after 4 h in the salmeterol arm (0.174 L; 0.144-0204) and after 5 h (0.141 L; 0.115-0.168) inthe placebo arm; after 12 h, the mean (95% Cl) increase in FEV1 from basal values was still 0.149 L (0.119-0.179) in salmeterol arm, but only 0.041 L (0.017-0.064) in placebo arm. The mean (95% CI) FEV1 AUC0-12h for all patients were 2.01 (1.72-2.30) L when salmeterol was added and 1.30 (1.03-1.58) L when placebo was inhaled. The difference (mean; 95% CI) between the FEV1 AUC0-12h of the two arms (0.71 L; 0.47-0.95) was statistically significant (P<0.0001), although the difference (mean; 95% CI) between the FEV1 AUC0-4h of the two treatments (0.08 L; -0.02-0.18) was notstatistically significant (P=0.126). The addition of an extra dose of salmeterol did not significantly increase the heart rate or decrease the SpO2. This study suggests that the addition of an extra dose of salmeterol does not give room for further increase in peak FEV1, but the effect of adding salmeterol to salmeterol is largely additive when considering the duration of action and safe.

Serum potassium levels, CPK-MB and ECG in children suffering asthma treated with beclomethasone or beclomethasone-salmeterol

Asthma morbidity and mortality has increased. One of the possible causes is the excessive use of beta agonists. The aim of this study is to compare the effects of six week treatment with beclomethasone alone (Ibec) or the combination of beclomethasone-salmeterol (Ibe + Isal) on serum potassium (K), CPK-MB and ECG in children suffering asthma. It was a prospective, randomised, open cross-over trial. Patients received either Ib2 (2 puff/12 hr, 100 micrograms per puff) or Ibe + Isal (B 2 puff/12 hr, 100 micrograms per puff and S 2 puff/12 hr, 25 micrograms per puff) with dose meter inhaler by 6 weeks, with a four-week wash-out period between the treatments. K, CPK-MB and ECG were assessed at baseline, and after each treatment period. There were 9 girls and 20 boys, aged 11 +/- 2.18 (mean +/- SD) years, baseline K was 4.57 +/- 0.43 mEq/l, after B K 4.38 +/- 0.39 IU and after BS K 4.38 +/- 0.40. The CPK-MB level were baseline 14.75 +/- 4.5, after B 20.10 +/- 6.9 and after BS 21 +/- 8.05 (p < 0.05). Baseline QTc was 0.416 +/- 0.02 msec, after B 0.425 +/- 0.027, and after BS 0.415 +/- 0.029. We conclude that the treatment of children with asthma with 400 micrograms per day of Ibec or concomitantly with 100 micrograms of Isal for 6 weeks does not alter the serum K+ or the QTc. However, the CPK-MB has a significant increment with both treatments but without clinical and/or ECG changes. We can't affirm that Ibec or Ibec plus Isal have a cardiotoxic side-effect by the only presence of high levels of CPK-MB. We agree that it is necessary a close follow up of these apparently asymptomatic patients not induce important cardiovascular changes although CPK-MB was increased.

Long-acting beta2 agonists in the management of stable chronic obstructive pulmonary disease

Long-acting beta2 agonist bronchodilators (e.g. formoterol, salmeterol) are a new interesting therapeutic option for patients with chronic obstructive pulmonary disease (COPD). In the short term, both salmeterol and formoterol appear to be more effective than short-acting beta2 agonists, and in patients with stable COPD they are more effective than anticholinergic agents and theophylline. Regular treatment of patients with COPD with long-acting beta2 agonists can induce an improvement in the respiratory function and certain aspects of quality of life. Moreover, salmeterol seems to be better than ipratropium and theophylline in improving lung function at the recommended doses after a long term treatment. Use of combination therapy of a long-acting inhaled beta2 agonist and an anticholinergic agent or theophylline in patients with COPD has not been sufficiently studied. Combination of usual doses of ipratropium or oxitropium with usual doses of salmeterol or formoterol does not appear to improve pulmonary function, but this lack of improvement with the combination should not, in itself, prevent implementation of further therapeutic steps in patients responsive to an anticholinergic agent and/or salmeterol or formoterol administered singly. Neither formoterol nor salmeterol elicit significant cardiovascular effects in healthy individuals and patients with reversible airway obstruction. However, adverse cardiac events might occur in patients with COPD with pre-existing cardiac arrhythmias and hypoxaemia if they use long-acting 12 agonists, although the recommended single dose of salmeterol 50 microg or formoterol 12 microg ensures a relatively higher safety margin than formoterol 24 microg. The bronchodilatory effect of long-acting beta2 agonists seems to be fairly stable after regular treatment with these bronchodilators. Moreover, pre-treatment with a conventional dose of formoterol or salmeterol does not preclude the possibility of inducing further bronchodilation with salbutamol in patients with partially reversible COPD. All these findings support the use of long-acting beta2 agonist bronchodilators as first-line bronchodilator therapy for the long term treatment of airflow obstruction in patients with COPD. However, since physicians must always choose a drug that is highly efficacious, well tolerated and inexpensive, the cost-effectiveness analysis in relation to other bronchodilators will determine the proper place of long-acting beta2 agonists in the long term therapy of stable COPD.

Salmeterol administration by metered-dose inhaler alone vs metered-dose inhaler plus valved holding chamber

STUDY OBJECTIVE

To determine whether a spacer device designed as a valved holding chamber with a flow signal increases the efficacy of the long-acting beta(2)-agonist, salmeterol, in patients who use incorrect technique with metered-dose inhaler (MDI) alone.

DESIGN

Double-blind, randomized, placebo-controlled study.

SETTING

University hospital outpatient rooms.

PATIENTS

Twenty adult outpatients with stable persistent asthma, receiving a daily anti-inflammatory drug.

INTERVENTIONS

Patients were randomized to either salmeterol MDI (incorrect use: 1 s after actuating MDI, inhale rapidly) and placebo plus spacer (correct use: inhale slowly as MDI is actuated, continue to inhale slowly and deeply) or placebo MDI (incorrect use) and salmeterol plus spacer (correct use). The following week, patients received the opposite treatment. The dose was two puffs from each device on each treatment day; each puff was separated by 1 min.

MEASUREMENTS AND RESULTS

After baseline peak expiratory flow (PEF), salmeterol was administered and serial PEF determined (0.5, 1, 2, 3, 4, 6, 8, 10, and 12 h). Administration of salmeterol MDI plus spacer resulted in significantly greater increases in PEF from baseline vs MDI at 4 h (44 L/min vs 10 L/min; p < 0.01) and 6 h (49 L/min vs 24 L/min; p < 0.05). Both methods of administration were equally well tolerated.

CONCLUSION

We conclude that patients who have poor timing and rapid inhalation with salmeterol MDI alone will have greater increases in PEF at 4 h and 6 h and no additional side effects if the dose is administered with a valved holding chamber that is used correctly. Further study is needed regarding other errors in MDI technique with salmeterol.