Dear Doctor,

My 5-year-old daughter has asthma. What are the dangers or effects of using an asthma preventer long-term? I heard that using it for years might cause bone shrinkage. Is it true? Kate -----

Dear Kate,

Asthma is a state of hyperresponsiveness of the airways of the lungs, which facilitate the passage of air to and fro from the lungs. Airways get inflamed and close  after exposure to certain substances, which can produce allergy in some individuals(allergens). It is manifested by cough, wheezing and breathlessness.

It is a life long problem for which no cure is available. Drugs are available which can prevent or abort an attack or minimise the symptoms.  Corticoids have been found to be useful in preventing an  acute attack of asthma and keep the affected person comfortable in chronic asthma. This is because of their anti inflammatory action.  They are not very useful in acute attacks, where other medicines are used.

Corticosteroids  are similar to the corticosteroids produced by the adrenal medulla of the body.  Long term use of these externally used steroids, tends to affect the endogenous production of them, thus making the body dependant on external steroids. They tend to raise the blood pressure and blood sugar. Thus they can precipitate or aggravate hypertension and or diabetes. The bone density is reduced leading to softening at an early age. They can cause swelling of the face and feet. In young girls it can cause masculinizing features; like increase in body hair and hoarse voice.  Most  importantly, these steroids  reduce the immunity of the body, thus impairing the ability to fight diseases.  However, these adverse effects develop if they are used regularly over a long time. The    adverse effects of preventer medicines  is less harmful than attacks of asthma. Uncontrolled asthma can cause much discomfort , long term damage to the lungs and even respiratory failure leading to death

Considering these adverse effects, steroids are given in a lowest possible dose, in inhaled form. The onset of action in this form is also more  rapid as compared to when taken in a pill form.  But they are not absolutely free from side effects. Long term use of steroid inhalers can give rise to fungal infection in the mouth, cataracts and osteoporosis. The risk of osteoporosis with inhaled corticoids is much less as compared with oral steroids.

One should clearly weigh the risks of  asthma attacks versus use of corticoids, discuss it with his treating doctor and then go ahead with use of inhaled corticoids.