Once upon a time (1980) albuterol was called a long-acting bronchodilator because its effects lasted for up to 6 hours.
Earlier drugs were not as good. Alupent (metaproterenol) last 3-4 hours, isoetherane 1 hour, Epinephrine 20 minutes. Theophylline, an oral bronchodilator, lasted 1-2 hours in non time-release tablets. These other drugs caused tremor, arrhythmias, and stomach upset. Albuterol was a great advance.
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