Possibilities differ depending on the class, dose, and delivery
As with all drugs, there are side effects associated with asthma medications. The range of possibilities is wide, from oral thrush to nervousness to glaucoma and more. Side effects can vary not only by drug class and dose, but by whether the asthma drug is inhaled or taken by mouth.
In most cases, the asthma medications are well-tolerated, and the benefits of treatment outweigh the consequences. There may be times, however, when a side effect is more severe and requires either a dose adjustment or a change of treatment entirely.
Inhaled corticosteroids (commonly known as inhaled steroids) are prescribed to help prevent the symptoms of asthma. When used regularly, they help decrease the frequency and severity of asthma attacks. However, they will not relieve an attack once it has started.
Inhaled corticosteroids can cause both local side effects (limited to a part of the body) and systemic side effects (affecting the entire body). Systemic effects tend to be more severe and are typically associated with long-term use.
Among the possibilities:1
Oral candidiasis (thrush), a common fungal infection of the mouth
Dysphonia (hoarseness), usually short-term
Sore mouth or throat
Reflex cough or tracheal (windpipe) spasms
Decreased bone density in adults
Impaired growth in children, generally slight
Cataracts (clouding of the eye)
Glaucoma (increased pressure in the eye)
The use of a spacer on the mouthpiece of an inhaler may reduce the risk of side effects from inhaled corticosteroids. Rinsing and gargling after use may also prevent hoarseness and oral thrush.2
Short- and Long-Acting Beta Antagonists
Short-acting beta antagonists (SABAs) like albuterol are typically used as rescue medications to provide the quick relief of asthma symptoms. By contrast, long-acting beta-agonists (LABAs) like Severant (salmeterol) continue to work for 12 hours or more.
The side effects are much the same for SABAs and LABAs since the two drug classes share similar mechanisms of action. Side effects include:3
Increased heart rate
Nervousness or tremors
Though the side effects tend to resolve quickly with SABAs, they can often persist with LABAs. The same can occur when beta antagonists are used excessively.
While the overuse of a rescue inhaler can increase your risk of a severe asthma attack, that risk is multiplied if you overuse a LABA. So serious is the concern that the U.S. Food and Drug Administration (FDA) was prompted to issue a black box warning in 2003 advising consumers about the risk of fatal asthma attacks when using the combination inhaler Advair (fluticasone/salmeterol).4
Oral corticosteroids are typically used if you have experience or are at risk of a serious asthma attack. While steroids are delivered intravenously in a hospital setting, they are given in oral form if your symptoms are severe but do not require hospitalization.
Side effects are similar to those for inhaled steroids, albeit more common and severe. They include:5
High blood pressure
Elevated blood sugar
Growth suppression in children
Osteoporosis (bone density loss) in adults
Type 2 diabetes
If you require an oral steroid like prednisone two or more times per year, your asthma is not being well controlled.6 See your doctor and discuss whether an adjustment of treatment is needed.
Singulair (montelukast) and other leukotriene modifiers work by blocking a substance called leukotriene, which can trigger bronchoconstriction (narrowing of the airways) leading to an asthma attack.
Leukotriene modifiers are generally well tolerated but do have a number of common side effects, including:7
Nausea or vomiting
Generally speaking, side effects develop within the first month of treatment. Children using leukotriene modifiers may also experience hyperactivity.7
Mast Cell Stabilizers
Cromolyn sodium and Alocril (nedocromil) are mast cell stabilizers used for those with mild persistent asthma. These drugs work by preventing mast cells, a type of white blood cell, from secreting inflammatory substances called histamine into the bloodstream.
Cromolyn sodium and Alocril are generally well tolerated with most side effects decreasing with use. These include:8
A bad taste in the mouth
Itchy or a sore throat
Anaphylaxis is a whole-body, potentially life-threatening allergic reaction. If not treated immediately, people with anaphylaxis may experience shock, coma, asphyxiation, heart or respiratory failure, and even death.
Xolair (omalizumab) is an immunomodulator delivered by injection. The aim of the treatment to alter the way that the immune system responds to an asthma trigger—essentially preventing it from over-responding.9
Because immunomodulators suppress parts of the immune system, you may be prone to frequent mild-to-moderate infections.
Other common side effects include:10