Since the 1950s, cortisone and related steroids, when taken by mouth, have been used to reduce inflammation in the airways. Drugs such as dexamethasone (Decadron) or methylprednisolone (Medrol) produce dramatic relief of symptoms in severe cases of chronic asthma, reducing the number of attacks and their severity. When used during the early stages of asthma, they can prevent the worsening of this respiratory disorder.
Because symptoms recur when these steroids are discontinued, they are commonly taken orally over extended periods, but such drugs can cause a very wide range of adverse systemic effects, some of which are quite dangerous. These include interference with the body’s capacity to respond to infections or injury, alterations in the body’s salt and water balance, abnormalities in metabolism that can lead to diabetes, and slowed growth in children. Sudden drug discontinuation after taking oral steroids for several weeks shuts down the body’s normal production of hydrocortisone (cortisol), which impairs the immune response to stress and infections.
During the 1970s, beclomethasone (Beclovent) and similar steroids became available that could be effectively inhaled and delivered directly to the sites in the airways that were inflamed. The beneficial effects, fully comparable to those obtained when the drugs are taken orally, occur at a fraction of the oral dose. As a consequence, the frequency, extent, and severity of the systemic side effects are markedly reduced.
Since the 1950s, metered-dose inhalers (MDIs) have replaced squeeze-bulb nebulizers that were previously used to deliver inhaled drugs. MDIs are devices that use a propellant to deliver fixed and accurate doses of medication as a mist that is inhaled.
MDIs are now commonly used for the treatment of asthma and other respiratory conditions, and inhaled steroids are the first drugs doctors prescribe for the prevention of asthmatic attacks. However, these steroids should never be used as emergency antiasthmatics (as albuterol/salbutamol is) to arrest an imminent or ongoing attack, because they can irritate the airways and temporarily worsen the symptoms.
SEE ALSO Cortisone (1949), Albuterol/Salbutamol (1968), Ephedra/Ephedrine (1994).
Metered-dose inhalers (MDIs) are used to deliver fixed and accurate doses of many asthma medications. The patient obtains rapid relief from asthma symptoms when the drug is inhaled as a mist.