Chapter 44: What are the side effects of the inhaled steroids if used for many years?
When steroid tablets are taken for many months or years, harmful side effects are likely and almost inevitable. The list of possible effects is long; it includes mood changes, forgetfulness, hair loss, easy bruising, a tendency toward high blood pressure and diabetes, thinning of the bones (osteoporosis), suppression of the adrenal glands, muscle weakness, weight gain, cataracts, and glaucoma. After being swallowed, these tablets are absorbed from the stomach into the bloodstream and taken not only to the bronchial tubes (to treat asthma) but also to every other part of the body. Their effects are widespread.
On the other hand, only miniscule amounts of steroid medication enter the bloodstream after inhaling it. The reasons for this difference include the following. First, steroids used for inhalational treatment of asthma are designed not cross well from the surface of the bronchial tubes into the bloodstream. Somewhat like applying a steroid cream to the skin, they are poorly absorbed from the surface into the blood. Second, only very small amounts of steroid medication are delivered from the inhalers with each dose or "puff." Less medicine is needed when it can be directly applied to the affected area. We measure the amounts of steroids inhaled in micrograms, which are units one thousand times smaller than the milligrams by which we measure prednisone or Medrol® tablets.
When breathed in, some steroid medicine remains in the mouth and can be swallowed into the stomach and from there absorbed into the bloodstream. You can minimize any effect from steroids left behind in your mouth in two ways. First, use a spacer tube with your steroid spray. (A spacer can not be used with budesonide [Pulmicort®] dry powder inhaler.) Medicine that would otherwise land on your tongue and mouth stays in the spacer chamber. The part of the spray that passes through the spacer also tends to pass through your mouth and proceed down onto the bronchial tubes. Second, rinse your mouth with water after inhaling the steroid spray. Rinsing removes any medicine residue from your mouth. The portion of the medicine that helps your asthma remains undisturbed on your bronchial tubes.
So much for the theory; what about the actual experience with steroids in inhaled form? The current generation of steroid inhalers first began to be used in the mid 1960s. For more than three decades they have been prescribed for millions of people with asthma and other lung diseases worldwide. No serious long-term adverse effects have emerged. For adults, given in the usual doses, they do not cause degeneration (atrophy) of the normal tissues of the respiratory passageway. They do not predispose to lung infections. They do not cause cancer, diabetes, or high blood pressure.
We need to look more carefully at the two phrases used above: "for adults" and "in the usual doses." Children's bones may be sensitive to the very small amounts of steroids that can enter the bloodstream after inhalation. There is currently debate — and considerable on-going research — to determine whether in children inhaled steroids might slow bone growth and reduce a child's ultimate height.
Also, when given in very large doses (many puffs from a high-concentration steroid inhaler), the amount of steroid medicine that spills over into the bloodstream can become significant. Although the effect is small, like a very small dose of prednisone, over the years this small effect can potentially add up to serious harmful effects. High doses of inhaled steroids taken for a long time can probably predispose to cataracts, glaucoma, and thinning of the skin and bones. As a result, your doctor will probably only have you take high doses of inhaled steroids as a means to avoid steroid tablets. And he/she will constantly work with you to attempt to reduce the dose of inhaled steroids to a more conventional and safer range.
Remember that not taking inhaled steroids for fear of side effects may have real consequences that are far worse than potential effects in the future; namely, asthma symptoms and risk of asthma attacks now. Severe asthma attacks are usually treated with steroid tablets, which all agree have the worst side effects.