Arrhythmogenicity from combined bronchodilator therapy in patients with obstructive lung disease and concomitant ischemic heart disease

Drug treatment of COPD

Anticholinergics (in particular, ipratropium bromide [Atrovent]) are first-line therapy in patients with chronic obstructive pulmonary disease (COPD). Although more studies are needed to support the use of combination therapy, adding an inhaled beta agonist to the therapeutic regimen is reasonable in patients who remain symptomatic and need quick relief. Patients frequently receive inadequate amounts of drug with standard doses delivered by metered-dose inhalers, often as the result of improper technique, so symptomatic patients may require higher doses. Caution is recommended when the dose of inhaled sympathomimetics is increased in COPD patients with ischemic heart disease or tachyarrhythmias. The addition of an oral sympathomimetic is seldom necessary. Theophylline may be considered in outpatients who remain symptomatic despite their use of inhaled bronchodilators, but heart disease, seizure disorders, and gastroesophageal reflux are contraindications. Corticosteroid therapy remains controversial but can be helpful in patients who still have severe disease despite maximum bronchodilator therapy. Antibiotics can be of benefit in COPD patients undergoing an exacerbation who have increasing dyspnea, cough, and phlegm production.

Oral theophylline for chronic obstructive pulmonary disease

BACKGROUND

Oral theophylline has, for many years, been used as a bronchodilator in patients with COPD. Despite the introduction of new drugs, and its narrow therapeutic index, theophylline is still recommended for COPD treatment.

OBJECTIVES

To determine the effectiveness of oral theophylline when compared to placebo in patients with stable COPD.

SEARCH STRATEGY

The Cochrane Airways Review Group and Cochrane Controlled Clinical Registers were searched.

SELECTION CRITERIA

All studies were randomised controlled trials (RCTs).

DATA COLLECTION AND ANALYSIS

Data were independently abstracted and the methodological quality assessed by two reviewers.

MAIN RESULTS

Twenty RCTs met the inclusion criteria. Concomitant therapy varied from none to any other bronchodilator plus corticosteroid (oral and inhaled). The following outcomes were significantly different when compared to placebo. FEV1 improved with treatment: Weighted Mean Difference (WMD) 100 ml; 95% Confidence Interval (95%CI) 40, 160 ml. Similarly for FVC: WMD 210 ml 95%CI 100, 320. Two studies reported an improvement in VO2max; WMD 195 ml/min, 95%CI 113,27). At rest, PaO2 and PaCO2 both improved with treatment (WMD 3.2 mmHg; 95%CI = 1.2, 5., and WMD -2.4 mmHg; 95%CI = -3.5, -1.2, respectively). Walking distance tests did not improve (4 studies, Standardised Mean Difference 0.30, 95%CI -0.01, 0.62), neither did Visual Analogue Score for breathlessness isn two small studies (WMD 3.6, 95%CI -4.6, 11.8). The Relative Risk (RR) of nausea was greater with theophylline (RR 7.7; 95%CI 1.5, 39.9). However, patients' preference for theophylline was greater than that for placebo (RR 2.27; 95%CI = 1.26, 4.11). Very few patient withdrew from these studies for any reason.

REVIEWER'S CONCLUSIONS

Theophylline has a modest effect on FEV1 and FVC and slightly improves arterial blood gas tensions in moderate to severe COPD. These benefits were seen in patients receiving a variety of different concomitant therapies. Improvement in exercise performance depended on the method of testing. There was a very low dropout rate in the studies that could be included in this review, which suggests that recruited patients may have been known by the investigators to be theophylline tolerant. This may limit the generalisability of these studies.

Fatal adverse drug events: the paradox of drug treatment

OBJECTIVE

Study patient characteristics, morbidity patterns and drug regimens associated with fatal adverse drug events (FADEs) amongst medical department inpatients.

DESIGN

An observational, descriptive study using aggregated medical records, autopsies and pre and postmortem drug analyses.

SETTING

A department of internal medicine at a Norwegian county hospital.

SUBJECTS

All patients dying in the department over a 2-year period.

RESULTS

The incidence of FADEs were 18.2% (133/732). Compared with non-FADE cases, FADE cases were older, used more drugs both on admission and at death, and had higher comorbidity (P < 0.001). Drugs suspected to cause or contribute to fatal outcome were mainly those used for treating chronic pulmonary diseases (terbutaline, theophylline), antithrombotic drugs (aspirin, warfarin, heparines) and drugs for treating coronary heart disease and heart failure (e.g. diuretics, nitrates, angiotensin converting enzymes (ACE) inhibitors, calcium channel blockers). Bronchodilatory drugs, antithrombotic drugs and cardiovascular drugs account for 26, 31 and 30 FADE cases, respectively. Patients dying from gastrointestinal diseases had the highest relative FADE occurrence (42%), cancer patients the lowest occurrence (4%). Serious drug-drug and drug-disease interactions were frequently suspected. Various degrees of inappropriateness in choice of drug, dosage or administration route were seen in 50% of FADE cases.

CONCLUSIONS

This study shows a high incidence of FADEs associated with high age, high comorbidity and polypharmacy, and partly to inappropriate drug prescribing or use. Treatments frequently associated with FADEs were bronchodilatory treatment of patients with both chronic obstructive lung disease and coronary heart disease, vasodilatory treatment in patient with endstage heart failure and the combination of several antithrombotic drugs. A systematic strategy is needed to avoid unnecessary adverse drug events (ADEs).

Salbutamol inhalation has no effect on myocardial ischaemia, arrhythmias and heart-rate variability in patients with coronary artery disease plus asthma or chronic obstructive pulmonary disease

OBJECTIVES

Inhaled beta-2 agonists raise heart rate, systolic blood pressure and contractility, all of which cause an increase in oxygen consumption of the heart. We performed a study on the influence of inhaled salbutamol on myocardial ischaemia, rhythm, and heart rate variability as assessed by Holter monitoring of 24 patients with coronary artery disease (CAD) and clinically stable asthma or chronic obstructive pulmonary disease (COPD).

DESIGN

In hospital the patients received 0.2 mg (hour 1), 0.4 mg (hour 6), 0.8 mg (hour 13) of salbutamol with a metered-dose inhaler and a spacer, and 5 mg (hour 25) with a nebulizer; symptoms, peak expiratory flow (PEF), 30-h Holter monitoring, and blood pressure (BP) were recorded. The study parameters were compared for the hour preceding and following each dose of salbutamol.

RESULTS

No cardiac symptoms were associated with salbutamol inhalation. PEF increased after all doses (P < 0.005). A dose of 0.2 mg salbutamol induced no changes in heart rate, whereas dose of 0.4 mg increased heart rate from a mean of 75 +/- 13 to 79 +/- 14 beats min-1 (P < 0.005), and a dose of 0.8 mg from 76 +/- 14 to 78 +/- 15 beats min-1 (P < 0.05). No changes in systolic BP appeared after any dose of salbutamol. The diastolic BP was lowered after 0.8 mg of salbutamol from 86 +/- 12 to 82 +/- 10 mmHg (P < 0.05). The 5 mg of nebulized drug provoked no significant changes in heart rate or BP. Myocardial ischaemia, heart rate variability and ventricular arrhythmias remained unaltered with all doses.

CONCLUSIONS

The commonly used doses of inhaled or nebulized salbutamol induced no acute myocardial ischaemia, arrhythmias or changes in heart rate variability in patients with CAD and clinically stable asthma or COPD.

Chronotropic effects of cilostazol, a new antithrombotic agent, in patients with bradyarrhythmias

Whether phosphodiesterase inhibitors increase the heart rate in patients with bradyarrhythmias is not known. We attempted to determine whether the oral phosphodiesterase inhibitor cilostazol exhibits beneficial chronotropic effects in patients with symptomatic bradyarrhythmias. Twenty patients comprising eight with bradycardic atrial fibrillation, eight with sick sinus syndrome, and four with Wenckebach-type atrioventricular block, whose 24-h total heart-beat count was < or =70,000 beats and whose maximal RR interval was > or =2.5 s, were enrolled. Holter recordings (24-h) were made before and 2 weeks after oral daily administration of 200 mg of cilostazol. Cilostazol increased the 24-h total heart-beat count from 77,429 +/- 11,168 to 107,981 +/- 13,536 (95% confidence interval, 24,605-36,497; p < 0.0001), the minimal heart rate from 33 +/- 9 47 +/- 13 beats/min (95% confidence interval, 9-19 beats/min; p < 0.0001), and the maximal RR interval from 3,149 +/- 1,018 to 2,087 +/- 601 ms (95% confidence interval, -1,517 to -608 ms; p = 0.0001). Only two patients had headaches as adverse effects. In conclusion, cilostazol had a beneficial positive chronotropic effect in patients with bradyarrhythmias, especially with bradycardic atrial fibrillation and sick sinus syndrome.

Pharmacological treatment in acute exacerbations of chronic obstructive pulmonary disease

Exacerbations of chronic obstructive pulmonary disease (COPD) are usually treated with bronchodilator therapy, glucocorticoids and antibiotics. However, there are few experimental data on the effects of these agents in patients with acute COPD. A beta(2)-adrenoceptor agonist is usually given first because it can be expected to produce a rapid response. An anticholinergic agent should also be given when the patient is severely ill or responds inadequately to the beta(2) agonist. These agents can be administered via a nebuliser or using a metered-dose inhaler in conjunction with a spacer device. Glucocorticoids can accelerate recovery if the standard empirical regimens for acute exacerbations of asthma are used, although a longer treatment duration appears to be required. Theophylline provides little additional benefit in patients who receive frequent doses of inhaled bronchodilators and an adequate dosage of a glucocorticoid. Although the role of bacterial infections is not completely understood, the use of antibiotics is justified in patients with severe airflow limitation who have febrile tracheobronchitis.

Cardiac arrhythmias after inhaled bronchodilators in patients with COPD and ischemic heart disease

Selective beta 2-agonist aerosols may produce significant cardiovascular effects. In the present study we used Holter monitoring to compare the arrhythmogenic effects of inhaled terbutaline (TE), a beta 2-agonist, with that of ipratropium bromide (IB), a nonabsorbable cholinergic drug. Fourteen patients with concomitant obstructive lung disease, ischemic heart disease, and complaints of postinhalation palpitations were studied in a random, double-blind, cross-over fashion. Both drugs significantly improved vital capacity and FEV1. Heart rate and the frequency of premature beats were not significantly affected by the bronchodilators. We conclude that no clear connection between inhaled bronchodilators and arrhythmias could be demonstrated.

Effects of oral theophylline on sick sinus syndrome

OBJECTIVES

We sought to determine the effect of theophylline on cardiac pauses in sick sinus syndrome.

BACKGROUND

Sick sinus syndrome, a relatively benign condition, is usually treated with pacemaker implantation without any proved effectiveness. Thus, an appropriate pharmacologic therapy would be useful.

METHODS

Theophylline (200 to 400 mg/day for 1 month) was initially administered orally to 17 patients with sick sinus syndrome, which is manifested by sinus pauses of > 2.5 s. Eleven of the 17 patients subsequently received theophylline for an additional 8 to 37 months. Twenty-four-hour Holter recordings were obtained before treatment, at the end of 1 month of treatment and then at 6-month intervals.

RESULTS

Theophylline decreased the frequency of sinus pauses from 256 +/- 230 to 23 +/- 62 pauses per 24 h and decreased the duration of the longest pauses from 4.7 +/- 1.8 to 2.2 +/- 0.97 s after 1 month of treatment. Subjective symptoms associated with cardiac pauses disappeared in 16 of 17 patients. Ventricular premature beats increased in frequency but did not last longer than two beats. Three patients experienced adverse effects. Nine of the 11 patients receiving long-term treatment had a good outcome, but 2 patients required a pacemaker because of the reappearance of long sinus pauses.

CONCLUSIONS

The results suggest that oral theophylline may be beneficial for the treatment of patients with sick sinus syndrome.

High serum albuterol levels and tachycardia in adult asthmatics treated with high-dose continuously aerosolized albuterol

To study the feasibility of using high-dose continuously aerosolized albuterol aerosol in adults, seven adult asthmatic patients were treated eight times with 0.4 mg/kg/h albuterol delivered by continuous nebulization over 4 h. One patient withdrew at 3 h after supraventricular tachycardia developed. This subsided promptly on discontinuing albuterol therapy. Heart rate increases were observed in six of eight treatments and serum albuterol levels at the end of treatment were greater than 25.0 ng/ml in all but one treatment. A mean increase in heart rate of 16.3 percent was observed for the entire group. Of the treatments with elevated (> 25.0 ng/ml) serum albuterol levels, a significant cumulative increase in heart rate was observed with time. A significant improvement of FEV1 was observed (p = 0.0025) with a net increase of 36.8 percent. These data suggest that high-dose continuously aerosolized albuterol treatment in some adult asthmatics can result in markedly elevated serum albuterol levels and potential cardiac stimulation despite spirometric improvement.

Clinical effects of oral theophylline in sick sinus syndrome

In 17 patients with symptomatic sinus bradycardia (age: 66 +/- 11 years), a resting electrocardiogram, a 24-hour Holter recording, and a treadmill test were performed both before and after administration of slow-release theophylline (700 mg daily). The drug increased resting heart rate (46 +/- 7 versus 62 +/- 18 beats/min, p less than 0.01), mean 24-hour rate (51 +/- 6 versus 64 +/- 16 beats/min, p less than 0.01), and minimal 24-hour heart rate (36 +/- 6 versus 43 +/- 10 beats/min, p less than 0.05). Cardiac pauses greater than 2.5 seconds were present in four patients during control recording, and disappeared after theophylline. The daily number of premature supraventricular and ventricular beats increased slightly after the drug. Exercise heart rate was higher after theophylline than during the control test (p less than 0.01). Thirteen patients were followed for a period of 17 +/- 3 months. Suppression of symptoms was achieved in 12 patients. Asthenia and easy fatigue were reduced markedly by the drug. During long-term therapy, the sinus rate was similar to that observed at the steady-state evaluation. In 3 of the 17 patients theophylline had to be discontinued because of gastric intolerance (in two at the end of the steady-state evaluation and in one during long-term therapy). These data suggest that oral theophylline can represent an effective therapy in some patients with symptomatic sinus bradycardia.

Changes in the distribution of ventricular ectopic beats in long-term electrocardiograms

Only simple methods have been used to assess antiarrhythmic and proarrhythmic effects when comparing baseline and on-therapy Holter recordings taken from the same patient. The paper suggests a new method for definition of these effects based upon comparisons of statistical distributions of ectopic beats. The method is based on multiple random sampling of the recordings and on application of the Smirnov test to compare the samplings. The results of these multiple comparisons are subsequently evaluated using the chi-squared test. An analysis is reported of Holter recordings made on seven patients suffering from ventricular arrhythmia but with anatomically normal heart. In each patient, one baseline recording and one recording on each of three different drugs were made. The results show that the definition of proarrhythmic effects can be partly addressed in a precise mathematical way. The method can also detect a significant change in the character of arrhythmia which can neither be classified as antiarrhythmic nor as proarrhythmic.

Cardiac arrhythmias during theophylline toxicity. A prospective continuous electrocardiographic study

To examine the effects of theophylline toxicity on cardiac rhythm, patients underwent continuous ambulatory ECG recording during acute theophylline toxicity and recovery. The patients, who were recruited form inpatient wards, intensive care units, and emergency departments of a University Medical Center and a Veterans Administration Medical Center, had serum theophylline concentrations (STC) greater than 30 mg/L. There were 14 men and two women with a mean age of 66 years. Fourteen patients had COPD and developed toxicity following long-term theophylline overmedication. Two patients had asthma and ingested an intentional overdose. The STC at the onset of ECG recording ranged from 23 to 67 mg/L. The principal rhythm was sinus in 15 patients; one patient had atrial fibrillation. Sinus tachycardia (heart rate greater than 100/min) was common, and heart rate fell in proportion to STC as toxicity resolved. Supraventricular ectopic beats (SVEs) were noted in seven patients with multiple runs of SVE being present in four. One patient developed multifocal atrial tachycardia (MAT) during toxicity that resolved spontaneously. During the 11 +/- 8 hours of recording during toxicity (STC greater than 20 mg/L), 80 percent of patients had ventricular premature beats (VPBs), 44 percent had paired VPBs, and 25 percent had ventricular runs. One elderly patient with heart disease developed sustained ventricular tachycardia (VT) when STC = 66 mg/L. No other patient had ventricular ectopy that required intervention. During the 10 +/- 6 hours of recording during the "recovery phase" (STC less than 20 mg/L), all patients with VPBs continued to have ectopy; however, the number of VPBs declined significantly. A follow-up 24-hour ECG recording obtained one week after recovery from toxicity in the patient with sustained VT demonstrated marked reduction in the frequency and complexity of VPBs. Patients with frequent (greater than 10/h) or repetitive VPBs were older (p less than 0.05) than those without complex ectopy. There was a trend (p = 0.07) suggesting patients with underlying heart disease were at risk for having complex ventricular ectopy. We conclude that sinus tachycardia, SVE, and VPBs are common among patients with theophylline toxicity; however, sustained ventricular or supraventricular tachyarrhythmias that require antiarrhythmic therapy are uncommon.