Theophylline. Interactions

The toxic effects of theophylline, aminophylline, and other xanthines are additive. Use with other xanthine medications should therefore be avoided if intravenous aminophylline is to be given for acute bronchospasm in patients who have been taking maintenance theophylline therapy, serum-theophylline concentrations should be measured first and the initial dose reduced as appropriate (see Uses and Administration, below).