Theophylline, derived from tea, has a long history of use, but may not be as safe as doctors used to think. It can cause dramatic personality changes. Other drugs of this class can be inhaled to relieve and prevent attacks. Other inhalers contain steroids. If the steroids are not absorbed into the system, they can be safe and effective.
Different products vary greatly in efficacy and absorbability.
Steroid inhalers should always be used immediately following inhalation of a bronchodilator. Oral steroids are very dangerous for asthmatics, because it is too easy to become addicted to them, and toxicity from long-term steroid use is devastating. Try to avoid ever going on oral steroids. If you do have to take them, get off as soon as possible. In general, the less medication you can take, the better.