FDA OKs long-acting beta2-agonist with faster onset of action than salmeterol

By Joan Unger, RN, MS, ARNP

and James Chan, PharmD, PhD

There is good news for your asthma patients and those who suffer from exercise-induced bronchospasm. The Food and Drug Administration (FDA) recently approved formoterol inhalation powder, a long-acting, inhaled selective beta2-adrenergic receptor agonist. The drug is the second long-acting beta2-agonist on the market along with salmeterol (Serevent). Formoterol is approved for the maintenance treatment of asthma and the prevention of exercise-induced bronchospasm. Formoterol, which has been available in Europe, is marketed as Foradil by Novartis Pharmaceuticals.

Indications.

— Long-term maintenance of asthma control and the prevention of bronchospasm in adults and children 5 years and older;

— Acute prevention of exercise-induced bronchospasm in adults and children 12 years and older.1

The primary difference between formoterol and salmeterol is the faster onset of action of the formoterol,2 which is similar to albuterol. With twice-daily dosing, the benefit of faster onset may be negligible. Despite its faster onset of action, formoterol is not recommended for rescue use as its long duration of action may mask signs of more serious asthma.2 However, the faster onset of action of formoterol may be advantageous for the prevention of exercise-induced bronchospasm.

There have been a few case reports of patients with preferential response to formoterol compared to salmeterol. One study describes a patient with a significant response to formoterol but not to salmeterol.3 Another reports two asthma patients who experienced no effect on asthma symptom control and pulmonary function with inhalation of salmeterol, but a striking effect resulted when therapy was switched to inhaled formoterol.4

Foradil is administered as a dry powder and does not use a chlorofluorocarbons propellant. Salmeterol is available both as an aerosol and dry powder. Some patients may find the inhalation of dry powder difficult, especially if they are accustomed to aerosolized inhalers. Since the delivery system is self-actuated, drug delivery is sensitive to the patient’s inspiratory flow rate.5 Formoterol may have a greater potential to cause side effects such as tremors and effect on Q-T interval compared to salmeterol.6

These drugs appear to be comparable in improving pulmonary function in asthmatics in single-dose trials.2,6 In contrast to salmeterol formoterol has not been approved for the maintenance treatment of bronchospasm of chronic obstructive pulmonary disease, but it appears to be equally effective.7,8 Both drugs are priced similarly with a 30-day cost of about $70.

Clinical implications.

Long-acting beta agonists such as salmeterol and formoterol are recommended as alternatives to medium-dose inhaled corticosteroids in long-term management of moderate to persistent asthma.9

Formoterol provides a safe and effective alternative to salmeterol. Both are approved for use in adults and children, although salmeterol is approved down to age 4 compared to age 5 for formoterol.

Dosage.

— For long-term maintenance care of asthma control, the usual dose is inhalation of the contents of one capsule every 12 hours.

— For prevention of exercise-induced bronchospasm the dose is one capsule at least 15 minutes before exercise.

— Doses should not exceed two capsules per day.

— Formoterol is available as 12 mcg capsules and is administered with the Aerolizer Inhaler.

Nursing considerations.

In comparison with albuterol and placebo, patients treated with formoterol showed improved combined and nocturnal asthma symptom scores, fewer nighttime awakenings, fewer nights in which they required rescue medication, and higher morning and evening peak flow rates. Formoterol is not indicated for patients in whom asthma is managed by occasional use of inhaled, short-acting, beta2-agonists. However, it can be used safely and concomitantly with beta2-agonists, inhaled or systemic corticosteroids, and theophylline. Formoterol has no anti-inflammatory effect and cannot take the place of corticosteroids. Like similar drugs, formoterol fumarate should be used with caution in patients with cardiovascular disorders, especially coronary insufficiency, arrhythmias, and hypertension.

Patient education.

Caution patients that formoterol capsules must not be taken orally and should be used only with the inhaler. A foradil capsule is placed in the well of the Aerolizer Inhaler, and the capsule is pierced by pressing and releasing the buttons on the side of the device. The formoterol fumarate formulation is dispersed into the air stream when the patient inhales rapidly and deeply through the mouthpiece. Formoterol is not intended to treat acute asthma symptoms, and patients should not exceed the recommended dose. Patients who require oral or inhaled corticosteroids should continue their treatment, even if they feel better after initiating or increasing the dose of formoterol. If the usual dose becomes less effective or the patient requires more inhalation of short-acting beta2-agonist, a re-evaluation of the regimen is needed at once.

References

1. Foradil Product Information. Novartis Pharmaceutical; February 2001.

2. Barlow RA, RN Brogden. Drugs 1998; 55:303-322.

3. Noppen M, Vinckin W. Respiration 2000; 67:112-113.

4. Ulrik CS, Kok-Jensen A. Eur Respir 1994; 7:1,003-1,005.

5. Nielsen KG, et al. Eur Respir 1997; 10:2,105-2,109.

6 Palmqvist M, et al. Am J Respir Crit Care Med 1999; 160:244-249.

7. Celik G, et al. Respiration 1999; 66:434-439.

8. Cazzola M, Donner CF. Drugs 2000; 60:307-320.

9. National Institute of Health. Guidelines for the Diagnoses and Management of Asthma. Expert Panel Report 2. July 1997.