Correspondence

Correction

Management of Chronic Obstructive Pulmonary Disease

N Engl J Med 1993; 329:967-968September 23, 1993

Article

To the Editor:

In their review of the management of chronic obstructive pulmonary disease (April 8 issue),1 Ferguson and Cherniack state, “All persons who are at risk [for the disease] should be evaluated for airflow limitation with the use of spirometry. . . .[S]pirometry should be a part of routine examinations, since it provides valuable information on changes in lung function over time.” Why was such a definitive comment made?

Before routine diagnostic testing is recommended, there should be some indication of how the results will alter management. Since the risk factors for chronic obstructive pulmonary disease (i.e., smoking or occupational exposure) should in any event be avoided, why perform this test routinely, adding to the cost without providing a comparable increase in benefit?

Robert Matz, M.D.
Mount Sinai Medical Center, New York, NY 10029

1 References

1. 1

   Ferguson GT, Cherniack RM. Management of chronic obstructive pulmonary disease. N Engl J Med 1993;328:1017-1022
   Full Text | Web of Science | Medline

To the Editor:

In their recent review of the management of chronic obstructive pulmonary disease, Ferguson and Cherniack state in Table 2 that pirbuterol, a beta₂-agonist, is less beta₂-selective and has a shorter duration of action than albuterol. This conclusion is not supported by published data1-3.

In 12 patients with asthma, the improvement in the forced expiratory volume in one second after the administration of two puffs of pirbuterol (400 μg) or albuterol (200 μg) was similar3. Double-blind comparisons of inhaled pirbuterol with placebo established that pirbuterol has a median duration of action of more than five hours4. In five crossover studies comparing the functional effects of inhaled albuterol and pirbuterol for four hours after the administration of each drug, 80.8 percent of patients were still responding to pirbuterol after four hours, whereas only 67.3 percent were responding to albuterol. The magnitude of the response at four hours was higher in the patients still responding to pirbuterol than in the patients still responding to albuterol4. These data indicate that pirbuterol has a duration of action that equals or exceeds that of albuterol.

Thierry C. Chinet, M.D.
University of Paris, 92104 Boulogne, France

4 References

1. 1

   Moore PF, Constantine JW, Barth WE. Pirbuterol, a selective beta2 adrenergic bronchodilator. J Pharmacol Exp Ther 1978;207:410-418
   Web of Science | Medline

2. 2

   Windom H, Grainger J, Burgess C, Crane J, Pearce N, Beasley R. A comparison of the haemodynamic and hypokalaemic effects of inhaled pirbuterol and salbutamol. N Z Med J 1990;103:259-261
   Medline

3. 3

   Beumer HM. Pirbuterol aerosol versus salbutamol and placebo aerosols in bronchial asthma. Drugs Exp Clin Res 1980;2:77-83
   

4. 4

   Pitts NE, Borger AP, Ghaly MS, Salsburg DS, Gans DJ. Pirbuterol -- a new selective beta-agonist. Proc R Soc Med 1983;56:1-31
   

To the Editor:

We would like to add something from the ophthalmologist's point of view to the review by Ferguson and Cherniack. We have seen several patients in whom acute angle-closure glaucoma developed soon after treatment with an ipratropium inhaler was begun. Patients prescribed this drug or an equivalent agent should be warned to seek treatment if a red eye or misty vision develops. Such patients usually also have a headache and a fixed (or sluggish), semidilated pupil. The condition may occur in both eyes simultaneously.1 In addition, airways disease may develop in a patient undergoing long-term treatment with topical beta-blockers for glaucoma. The patient's physician may not be aware that the patient is using eyedrops, and the ophthalmologist may be unaware of the airways disease.

David Kinshuck, M.B., B.S., F.C.Ophth.
Tahira Malik, M.B., Ch.B.
Wolverhampton Eye Infirmary, Wolverhampton WV3 9QR, United Kingdom

1 References

1. 1

   Shah P, Dhurjon L, Metcalfe T, Gibson JM. Acute angle closure glaucoma associated with nebulised ipratropium bromide and salbutamol. BMJ 1992;304:40-41
   CrossRef | Web of Science | Medline

To the Editor:

I believe that there is a mistake in the dose of ipratropium in Table 2 of the review by Ferguson and Cherniack. The dose should be 0.02 mg per puff, or perhaps 0.018 mg per puff if one is using the American preparation. The dose of 0.18 mg per puff is an error.

Norbert K. Mulleneisen, M.D.
Klinikum Leverkusen, 51304 Leverkusen, Germany

Author/Editor Response

The authors reply:

To the Editor: We disagree with Dr. Matz. Clearly, avoidance of risk factors is important, yet many patients do not heed this warning. Early identification of chronic obstructive pulmonary disease with the use of spirometry may provide the added incentive for patients to avoid these risks, especially cigarette smoking. Because of the large reserve capacity of the lung, waiting for pulmonary symptoms delays diagnosis to a point at which serious lung damage is likely to be present. In a manner akin to the management of hypertension, regular spirometry can be used to diagnose acute airflow limitation and, with observation of trends (the rate of decline in the forced expiratory volume in one second), can be used to identify people with increased susceptibility to the disease. This approach should allow earlier diagnosis, lead to early intervention, and alter the long-term course. This is especially true of patients with hereditary predispositions, including alpha₁-antitrypsin deficiency, in whom overt risk factors may not be evident and the diagnosis may be missed or delayed without screening spirometry. Furthermore, spirometry adds little to the cost of an evaluation, and plays an essential part in management once the disease is identified and treatment is initiated.

In response to Dr. Chinet, the information provided in Table 2 of our review was gleaned from a literature search and compiled from several reviews of the pharmacotherapy of chronic obstructive pulmonary disease, which typically do not include pirbuterol1; a recent pharmacologic review of pirbuterol2; and an original investigation of the pharmacology of inhaled pirbuterol3. We have tried not to emphasize the use of one beta-agonist over another, but we believe these references support the data in the table.

In response to Drs. Kinshuck and Malik, we agree that pulmonary medications can affect the eye. Although they may be uncommon, it is important to be aware of the potential side effects of any medication.

Finally, Dr. Mulleneisen is correct. In converting micrograms to milligrams, we dropped a zero; the correct dose of ipratropium is 18 μg, or 0.018 mg, per puff.

Gary T. Ferguson, M.D.
Reuben M. Cherniack, M.D.
National Jewish Center for Immunology and Respiratory Medicine, Denver, CO 80206

3 References

1. 1

   American Thoracic Society. Standards for the diagnosis and care of patients with chronic obstructive pulmonary disease (COPD) and asthma. Am Rev Respir Dis 1987;136:225-244
   CrossRef | Web of Science | Medline

2. 2

   Richards DM, Brogden RN. Pirbuterol: a preliminary review of its pharmacological properties and therapeutic efficacy in reversible bronchospastic disease. Drugs 1985;30:6-21
   CrossRef | Web of Science | Medline

3. 3

   Littner MR, Tashkin DP, Calvarese B, Bautista M. Acute bronchial and cardiovascular effects of increasing doses of pirbuterol acetate aerosol in asthma. Ann Allergy 1982;48:14-20
   Medline