Broxaterol: Therapeutic Trials and Safety Profile

Abstract

The efficacy and the safety profile of broxaterol have been assessed in multicenter open studies and in some double-blind controlled clinical trials. Broxaterol (0.6–1.2 mg/day by metered dose inhaler or 0.5–1.5 mg/day orally, from 2 weeks to 1 year) produced a significant clinical improvement, an increase in FEV₁ and a decrease in supplemental anti-asthmatic drugs used in patients with reversible airflow obstruction and in asthmatic children. The increases in FEV₁ versus baseline were significantly maintained after the end of the treatment. Prompt disappearance of the asthmatic attack with significant improvement in lung function was observed in children. In two long-term controlled trials the respiratory effects of broxaterol nebulizer solution were significantly greater than placebo. Moreover, broxaterol by metered dose inhaler was more effective than salbutamol after 3 months follow-up, showing absence of tachyphylaxis. In long-term clinical evaluation, broxaterol has been shown to be well tolerated, with an incidence of adverse reactions equal to or less than that reported in the literature for other β₂-agonists. The side effects most frequently associated with broxaterol were tremor, nervousness and palpitations. They usually appeared to be slight, transient and dose-related, requiring withdrawal from clinical trials in only 12 patients out of 274 (4.4%). Clinically relevant changes in heart rate and blood pressure were never reported. Broxaterol was found not to modify the ECG or haematological, hepatic and renal laboratory tests. No metabolic abnormalities or hypokalemia were caused by long-term treatment with broxaterol.