High-dose Inhaled Albuterol in Severe Chronic Airflow Limitation

Abstract

Higher doses of inhaled albuterol have been shown to cause slightly more bronchodilatation than standard doses from a metered-dose inhaler in patients with severe chronic airflow limitation. Higher doses, however, carry an increased risk of side effects, and the optimum dose balancing benefit and adverse effects have yet to be established. We have therefore looked at objective and subjective evidence of beneficial and adverse effects after 4 doses of albuterol in 30 patients with chronic bronchitis, severe airflow limitation, and less than 200 ml increase in FEV1 after 200 micrograms inhaled albuterol. Subjects were given placebo, 400 micrograms, 1 mg, 2 mg, and 4 mg albuterol by dry powder inhaler in random order on separate days in a double-blind study, and FEV1, relaxed VC, PEFR, 12-min walk distance, finger tremor, oxygen saturation, heart rate, and arrhythmias were measured at intervals over 6 h. With increasing doses of albuterol, there was a significant dose-related increase in FEV1, VC, and PEFR, the maximal mean changes being 196 ml, 480 ml, and 50 L/min, respectively. The duration of effect was longer with the higher doses. There was a dose-related increase in heart rate, tremor amplitude, and supraventricular ectopic beats and a dose-related fall in oxygen saturation. There was no drug-related effect on the frequency of ventricular ectopic beats either at rest or during the walk tests. The largest increases in walk distance occurred after the 1 and 2 mg doses and the least after the 4 mg dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the Bronchodilator Effects of Salbutamol Delivered via a Metered-Dose Inhaler with Spacer, a Dry-Powder Inhaler, and a Jet Nebulizer in Patients with Chronic Obstructive Pulmonary Disease

“…Dose-response studies using salbutamol powder in patients with stable COPD demonstrated that although maximal improvements may be achieved following the administration of 1 mg or more [23, 24]. 0.8–1.0 mg of the drug appeared to offer the best balance between beneficial and adverse effects [23, 25]. Thus, 1,000 µg was chosen as the larger dose.…”

Dose response to inhaled salbutamol in chronic obstructive airways disease

“…Studies ofsubjects with COAD have tended to show only small improvements in mean parameters of airflow limitation with high dose compared to low dose inhaled beta-2 agonists although higher doses may have a longer duration of effect. [5][6][7][8] A number of points need to be considered in assessing these findings. First, only a minority of our patients had severe airflow limitation (FEVY < 1 litre).…”

Management Options in Chronic Obstructive Pulmonary Disease

“…Bronchodilation effects are dose-related; though higher doses, especially with β2 agonists, are associated with increasing frequency of side effects. 5 Anti-cholinergic therapy appears to be more efficacious in causing persistent bronchodilation than the short acting β2 agonists. 7 Combination therapy with both bronchodilators also causes significant airway dilation.…”