Formoterol appears to have faster onset than salmeterol and may be used for sudden attacks of asthma as well as for maintenance therapy. A multidose DPI preparation of formoterol (Oxis) is currently undergoing trials in the United States and should be available soon. Bambuterol is a drug that is converted by the body into another B-agonist, terbutaline. It is given by mouth and is effective for twenty-four hours. This once-a-day approach should be helpful, especially for patients with nocturnal asthma. Inhaled Corticosteroid Mometasone Mometasone is a highly potent topical steroid that is currently undergoing evaluation in the treatment of asthma and appears extremely promising. This medication has recently been introduced into the United States as a nasal spray (Nasonex) and has been found to be highly effective in the treatment of rhinitis. Investigational Corticosteroids Investigational agents in the inhaled steroid group undergoing trials at this time include rofleponide palmitate and tipredane. Further data on these and additional agents should be available soon. Immunomodulators Medications called immunomodulators that affect the immune response are also being investigated. These agents work along the same principle as corticosteroids that suppress the immune reaction. Anticholinergic Agents Oxitropium bromide is an anticholinergic bronchodilator similar to ipratropium bromide in its action. It appears to have a more potent effect and longer duration of action than ipratropium bromide. Xanthines Xanthines belong to the medication group that contains theophylline. Two agents, doxofylline and enprofylline, have been studied and used in Europe. Doxofylline appears to have fewer side effects compared to theophylline and has been approved for use in Europe. The lower risk of adverse effects should reduce the need for blood level monitoring.