Tuesday 29 May 2007

Inhaled corticosteroids for asthma

Our 2and a half-year-old son has repeated asthma attacks that usually respond to nebulizers at home but he has been hospitalized twice this year. His doctor and the hospital want to put him on a steroid preventer twice a day. I am concerned that the steroids will stunt his growth and give him other problems. What do you think?

Your concern is very common. So much so that a term “Steroid Phobia” has been coined for it. The term phobia is a bit harsh because corticosteroids can cause serious and minor side-effects if given in big doses. However, the dose of steroid given by puffers is so small that it will not cause these side-effects. The great beauty of the inhaled steroids is that they are delivered to where they are wanted – into the airways. They do not go to the rest of the body as they would if swallowed or injected. Any inhaled steroid that is absorbed from the lungs or accidentally swallowed, is 90% destroyed by the liver in 1 second. This means it does not get to other parts of the body and cannot cause side-effects.

Thus, if the correct dose is given, an effect on growth or side-effects is very unlikely. Occasional patients (I have only seen 1 in my career) are unduly sensitive and this will first show up as excessive weight gain. In this case some other preventer is tried. The other group of preventers are also inhaled and stop the release of chemicals in the airways that cause asthma. These are very safe but unfortunately only work in 75-90% of patients. You will need a 4-week trial of giving them twice a day before knowing if they will work or not. Yet another class of drugs called leukotriene inhibitors are relatively new and again seem not to work in everyone.

You specifically mentioned concern about stunting of growth. This has been well looked at by a 25-year trial in which 3 groups of children were followed. These were normal children, asthmatic children not given inhaled corticosteroids and a 3rd group with asthma who were given inhaled corticosteroids. The normal group grew best but importantly the asthmatics on steroids grew better than the asthmatics not given inhaled steroids. Also, the children with asthma given steroids were only a little bit shorter (about 1 inch or 2.5 centimetres) than the normal children.

As he has been hospitalized twice this year your son should be on a preventer.

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