Quick-Relief Medications

These medications quickly control acute asthma attacks.

Short-Acting Beta2-Agonists

Beta2-agonists do not reduce inflammation or airway responsiveness but serve as bronchodilators, relaxing and opening constricted airways during an acute asthma attack. They are used alone only for patients with mild and intermittent asthma. Patients with more severe cases should use them in combination with other drugs.

Asthma is a disease in which inflammation of the airways causes airflow into and out of the lungs to be restricted. When an asthma attack occurs, mucus production is increased, muscles of the bronchial tree become tight, and the lining of the air passages swells, reducing airflow and producing the characteristic wheezing sound.

Specific short-acting beta2-agonists include:

• Albuterol (Proventil, Ventolin), called salbutamol outside the U.S., is the standard short-acting beta2-agonist in America. Other similar beta2-agonists are isoproterenol (Isuprel, Norisodrine, Medihaler-Iso), metaproterenol (Alupent, Metaprel), pirbuterol (Maxair), terbutaline (Brethine, Brethaire, Bricanyl), and bitolterol (Tornalate). Isoetharine (Bronkometer, Bronkosol) is available in nebulizers.
• Newer beta2-agonists, including levalbuterol (Xopenex), have more specific actions than the standard drugs. Studies have indicated that levalbuterol is as effective as albuterol with fewer side effects. The original formulation of Xopenex was administered with a nebulizer. A new metered-dose inhaler formulation became available in late 2005.

Short-acting bronchodilators are generally administered through inhalation and are effective for 3 to 6 hours. They relieve the symptoms of acute attacks, but they do not control the underlying inflammation. If asthma continues to worsen with the use of these drugs, patients should discuss corticosteroids or other drugs to treat underlying inflammation.

Side Effects of Beta2-Agonists. Side effects of all beta2-agonists include the following:

• Anxiety
• Tremor
• Restlessness
• Headache
• Fast and irregular heartbeats. A doctor should be notified immediately if this side effect occurs, particularly in people with existing heart conditions. Such patients face an increased risk for sudden death from cardiac related causes. This risk is higher with oral or nebulized drugs, but there have also been reports of heart attacks and angina in some patients using inhaled beta2-agonists.

Beta2-agonists have serious interactions with certain other drugs, such as beta-blockers, and patients should tell the doctor about any other medications they are taking. Individuals with diabetes, existing heart disease, high blood pressure, hyperthyroidism, an enlarged prostate, or a history of seizures should take these drugs with caution.

Loss of Effectiveness and Overdose. There has been some concern that short-acting beta2-agonists become less effective when taken regularly over time, increasing the risk for overuse. Over time some patients may become tolerant to many effects of short-acting beta2-agonists. The degree to which this affects the airways is uncertain. In some studies, the duration of action has declined but the peak effect appears to be preserved, making these drugs still useful for acute attacks. Regular use of long-acting beta 2-agonists may reduce the effect of short-acting forms.

A 2005 landmark study suggested that patients’ differing clinical response to albuterol may be based on their genotype. Albuterol targets the beta-adrenergic receptor. In the Beta-Adrenergic Response by Genotype (BARGE) trial, researchers studied the effects of albuterol on patients with two different forms of this receptor. The results suggested that patients with the arginine form of the receptor did not respond to albuterol. These patients’ asthma symptoms actually improved when albuterol was not used. By contrast, patients with the glycine form of the receptor had improved asthma control with albuterol.

Patients who perceive beta2-agonists as being less effective may overuse them. Overdose can be serious and in rare cases even life-threatening, particularly in patients with heart disease.

Anticholinergic Drugs

Inhaled ipratropium bromide (Atrovent) acts as a bronchodilator over time. Ipratropium bromide alone is only modestly beneficial for acute asthma attacks. Moreover, the drug is not approved specifically for asthma. It may, however, have benefits in certain cases:

• It may be useful for certain older patients with asthma who also have emphysema or chronic bronchitis.
• A combination with a beta2-agonist might be helpful for patients who do not initially respond to treatment with a beta2-agonist alone.

Systemic Corticosteroids

Common oral corticosteroids include prednisone, prednisolone, methylprednisolone, and hydrocortisone. They very effectively reduce inflammation but are generally used only after hospitalization for an acute attack. In some severe cases, they may be used as maintenance.

Adverse effects of prolonged use of oral steroids include cataracts, glaucoma, osteoporosis, diabetes, fluid retention, susceptibility to infections, weight gain, hypertension, capillary fragility, acne, excess hair growth, wasting of the muscles, menstrual irregularities, irritability, insomnia, and psychosis. Osteoporosis is a common and particularly severe long-term side effect of prolonged steroid use. Medications that can prevent osteoporosis include calcium supplements, parathyroid hormone, bisphosphonates, or hormone replacement therapy in post-menopausal women.

Osteoporosis is a condition characterized by progressive loss of bone density, thinning of bone tissue, and increased vulnerability to fractures. Osteoporosis may result from disease, dietary or hormonal deficiency or advanced age. Regular exercise and vitamin and mineral supplements can reduce and even reverse loss of bone density.

Long-term use of oral steroid medications suppresses secretion of natural steroid hormones by the adrenal glands. After withdrawal from these drugs, this so-called adrenal suppression persists, and it can take the body a while (sometimes up to a year) to regain its ability to produce natural steroids again. There have been a few cases of severe adrenal insufficiency that occurred when switching from oral to inhaled steroids, which, in rare cases, has resulted in death.

No one should stop taking any steroids without consulting a doctor first. If the doctor orders steroids withdrawn, regular follow-up monitoring is necessary. Patients should discuss with their doctor measures for preventing adrenal insufficiency during withdrawal, particularly during stressful times when the risk increases.

---

Review Date: 3/18/2006
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.