Breath of Fresh Air: Feature Articles

The single most effective class of medications for control and prevention of asthma among adults is the group called inhaled corticosteroids. These anti-inflammatory medications improve lung function, reduce asthma symptoms, protect against asthmatic attacks, reduce the likelihood of being hospitalized for asthma, and improve the quality of life for many people with asthma. Examples include Aerobid®, Azmacort®, Beclovent®, Flovent®, Pulmicort®, and Vanceril®.

Inhaled steroids are the single most effective class of medicines for control and prevention of asthma among adults.

The great attraction of these anti-inflammatory steroids is that they can be delivered directly onto the bronchial tubes, where the allergic inflammation of asthma takes place. For regular, preventative use, they do not need to be taken as tablets by mouth. Steroid tablets taken by mouth, such as prednisone, are highly effective but carry with them a host of unpleasant -- and sometimes harmful -- side effects, particularly after taking them for many months and years. By breathing the steroid medication onto the airways, you can avoid all of the adverse side effects that occur when steroids are taken by mouth, absorbed from the stomach into the bloodstream, and carried by the blood to every part of the body (not just to the bronchial tubes). Or can you?

Recent scientific investigations have sought to determine whether the long-term use of steroids by inhalation might have harmful effects on the eyes. Is it possible that small amounts of the steroid medication inhaled onto the bronchial tubes might make their way into the bloodstream and, after years of use, cause cataracts (clouding of the lens of the eye) or glaucoma (damage due to elevated pressure within the eye)? It has long been known that persons taking steroid tablets are more likely to develop cararacts and glaucoma than persons not taking these medications. Might the same be true for inhaled steroids?

Delivery of medication directly to the bronchial tubes minimizes its effects elsewhere, but can it eliminate them?

A recent large study conducted in Quebec, Canada asked whether persons over the age of 65 years treated for elevated eye pressure in that province (10,000 persons identified) were more likely be be taking inhaled steroids than a comparable group without elevated eye pressure (38,000 such persons identified). Overall, the answer was no: persons with glaucoma were no more likely to use inhaled steroids than those with normal eye pressure.

Overall, persons with glaucoma were no more likely to use inhaled steroids than those with normal pressures in their eyes.

However, when the researchers further analyzed their results, they found that a larger percentage of the patients with elevated eye pressure were taking high doses of inhaled steroids, that is, more than 1600 micrograms/day for at least 3 months. That dose is the equivalent of Beclovent® or Vanceril® at least 32 puffs/day, Azmacort® at least 16 puffs/day, or Aerobid® at least 6 puffs/day [also, Pulmicort® at least 8 puffs/day and Flovent 220 ug strength at least 7 puffs/day]. At these high doses of inhaled steroids, the risk of having elevated eye pressure or glaucoma was 40% increased above normal.

The affect of inhaled steroids on the risk of cataracts is similar. In a study of several thousand residents (aged 49-97 years) outside Sydney, Australia, the likelihood of having cataracts was found to be increased among those who were or had been taking inhaled corticosteroids. This study focused on patients taking beclomethasone (Beclovent® or Vanceril®) or budesonide (Pulmicort®). The highest risk was seen among persons with a lifetime dose of more than 2,000,000 micrograms.

Long-term use of large doses of inhaled steroids can also predispose to cataracts.

The message seems clear. At low and medium doses of inhaled steroids (generally, less than 1000 micrograms/day), inhaled corticosteroids pose no significant risk to vision and the eyes. At high doses, some of the medication enters into the bloodstream and has effects like those of prednisone, including the chance of cataracts and glaucoma. But remember, the reason that someone with asthma would be taking high doses of an inhaled steroid would be to control his or her asthma without having to resort to an oral steroid tablet. And it is widely agreed that whatever long-term side effects high doses of inhaled steroids may have, they are undoubtedly less than those encountered with chronic use of steroid tablets. The premise at the start of this article remains unchanged: inhaled steroids remain the most effective -- and safest -- way available today to control and prevent asthma.

A routine eye exam to test for cataracts and glaucoma is appropriate for anyone over age 65, especially if one is using inhaled corticosteroids regularly.

If you wish to have such an examination, do not hesitate to ask your doctor at the Asthma Center. We will facilitate an appointment with an ophthalmologist who can diagnose — and treat — any problem if it exists.

High-dose inhaled steroids remain safer than regular use of oral steroids, such as prednisone.