The combination of the inhaled corticosteroid budesonide (Pulmicort) with the long-acting beta₂-agonist formoterol (Foradil) in a single inhaler (Symbicort) was approved last July for long-term control of asthma in patients aged 12 years and older. This new medication offers a fast-acting combination therapy in the form of a metered-dose inhaler (MDI) that is similar to short-acting beta₂-agonists, such as albuterol (AccuNeb, Proventil).

Having a fast-acting combination therapy is expected to improve patient compliance, a considerable problem in all chronic diseases and especially in asthma.

Symbicort has been available in Europe since 2000 and is approved in more than 90 countries outside of the United States. The approval of this medication in the United States was based on data from 2 large, double-blind, placebo-controlled trials that included more than 1000 US patients.

In one of the studies, the 2 primary efficacy end points were mean change from baseline in morning predose forced expiratory volume in 1 second (FEV₁) and mean change from baseline in 12-hour FEV₁. Greater improvements were evident in patients randomized to budesonide/formoterol, whether combined in the same inhaler or administered in separate inhalers, compared with placebo. And fewer patients receiving both agents met the criteria for worsening asthma, compared with the monotherapy and placebo groups.

In both studies, all treatments were well-tolerated. Adverse events reported were mild or moderate and included nasopharyngitis, headache, upper respiratory tract infection, pharyngolaryngeal pain, sinusitis, influenza, back pain, nasal congestion, and stomach discomfort.

Prescribing Symbicort

Symbicort is indicated for long-term maintenance therapy of asthma in adults and adolescents.

It is available in 2 strengths: 80/4.5 µg and 160/4.5 µg budesonide and formoterol, respectively. Each dose should be administered as 2 inhalations twice daily, once in the morning and once in the evening. Instruct patients to rinse their mouth after every dose.

For patients currently receiving medium-to-high doses of inhaled corticosteroids, the recommended starting dose of Symbicort is 160/4.5 µg, 2 inhalations twice daily. For those currently receiving low to medium doses of inhaled corticosteroids, the starting dose of Symbicort is 80/4.5 µg, 2 inhalations twice daily. Either dosage strength can be used in patients not currently taking inhaled corticosteroids, depending on disease severity. Since long-acting beta₂-adrenergic agonists, such as formoterol, may increase risk of asthma-related death, Symbicort should only be prescribed to patients whose asthma is not adequately controlled with other asthma-controlling agents, such as low- to medium-dose inhaled corticosteroids, and to those whose disease severity warrants treatment with 2 maintenance therapies.

The National Institutes of Health asthma guidelines recommend using an inhaled corticosteroid and a long-acting inhaled beta₂-agonist, the 2 agents in Symbicort, for long-term symptom control in patients with moderate-to-severe persistent asthma.

Advair versus Symbicort

Fluticasone/salmeterol (Advair Diskus), a combination of the inhaled corticosteroid fluticasone (Flovent) and the long-acting beta₂-agonist salmeterol (Serevent Diskus) is available for long-term maintenance therapy for asthma, as well as for chronic obstructive pulmonary disease associated with chronic bronchitis. Advair Diskus is delivered in a dry-powder inhaler and has recently been approved as an MDI version, Advair HFA Inhaler.

The main difference between Symbicort and Advair Diskus is the duration to onset of action. Symbicort has a rapid onset of action, within 15 minutes, compared with a 30- to 60-minute onset of action with the 2 Advair formulations.