<p>Theophylline is a bronchodilator, structurally classified as a Methylxanthine. Theophylline has two distinct actions in the airways of patients with reversible obstruction; smooth muscle relaxation and suppression of the response of the airways to stimuli. Theophylline also increases the force of contraction of diaphragmatic muscles. The half-life of Theophylline is influenced by a number of known variables. In adult nonsmokers with uncomplicated asthma the half-life ranges from 3 to 9 hours</p>