Inhaled corticosteroids are the preferred medicine for long-term control of asthma. They’re the most effective option for long-term relief of the inflammation and swelling that makes your airways sensitive to certain inhaled substances.
Reducing inflammation helps prevent the chain reaction that causes asthma symptoms. Most people who take these medicines daily find they greatly reduce the severity of symptoms and how often they occur.
Inhaled corticosteroids generally are safe when taken as prescribed. These medicines are different from the illegal anabolic steroids taken by some athletes. Inhaled corticosteroids aren’t habit-forming, even if you take them every day for many years.
Like many other medicines, though, inhaled corticosteroids can have side effects. Most doctors agree that the benefits of taking inhaled corticosteroids and preventing asthma attacks far outweigh the risk of side effects.
One common side effect of inhaled corticosteroids is a mouth infection called thrush. You might be able to use a spacer or holding chamber on your inhaler to avoid thrush. These devices attach to your inhaler. They help prevent the medicine from landing in your mouth or on the back of your throat.
Check with your doctor to see whether a spacer or holding chamber should be used with the inhaler you have. Also, work with your healthcare team if you have any questions about how to use a spacer or holding chamber. Rinsing your mouth out with water after taking inhaled corticosteroids also can lower your risk for any infections in your mouth.
If you have severe asthma (need to define), you may have to take corticosteroid pills or liquid for short periods to get your asthma under control.
If taken for long periods, these medicines raise your risk for cataracts and osteoporosis (OS-te-o-po-RO-sis). A cataract is the clouding of the lens in your eye. Osteoporosis is a disorder that makes your bones weak and more likely to break.
Your doctor may have you add another long-term asthma control medicine so he or she can lower your dose of corticosteroids. Or, your doctor may suggest you take calcium and vitamin D pills to protect your bones.

• Omalizumab (anti-IgE). This medicine is given as a shot (injection) one or two times a month. It helps prevent your body from reacting to asthma triggers, such as pollen and dust mites. Anti-IgE might be used if other asthma medicines have not worked well.

A rare, but possibly life-threatening allergic reaction called anaphylaxis might occur when the Omalizumab injection is given. If you take this medication, work with your doctor to make sure you understand the signs and symptoms of anaphylaxis and what actions you should take.

• Inhaled long-acting beta2-agonists. These medicines open the airways. They might be added to inhaled corticosteroids to improve asthma control. Inhaled long-acting beta2-agonists should never be used on their own for long-term asthma control. They must used with inhaled corticosteroids.
• Leukotriene modifiers. These medicines are taken by mouth. They help block the chain reaction that increases inflammation in your airways.
  Theophylline. This medicine is taken by mouth. Theophylline helps open the airways.

If your doctor prescribes a long-term control medicine, take it every day to control your asthma. Your asthma symptoms will likely return or get worse if you stop taking your medicine.
Long-term control medicines can have side effects. Talk with your doctor about these side effects and ways to reduce or avoid them.
With some medicines, like theophylline, your doctor will check the level of medicine in your blood. This helps ensure that you’re getting enough medicine to relieve your asthma symptoms, but not so much that it causes dangerous side effects.