Question: Would you have any information on asthma and the use of steroids for it? My grandson has had asthma since he was very young. He is now 15. We are all so concerned about him. He is in high school, and his grades are not too good. He was always an honor student. His doctor had him on a nebulizer breather, and now he is giving him steroids. Is that wise? I am worried about side effects.

- Grandma

Answer: The steroids your grandson is getting are the cortisone type, the most powerful weapon against inflammation. Yes, it is all right to use such medicine in someone your grandson's age when the situation demands it.

You don't tell me the precise mode of steroid use prescribed.

Steroids can come in nebulizer sprays. When given that way, the steroid content has little effect on the rest of the body beyond the airways. So side effects would be rare.

When steroids are given by mouth in pill form to get a more powerful effect, they are prescribed for the briefest periods possible, to minimize undesired effects.

In short, steroids can be safely used in children with asthma without serious effects now or in later life.

I hope your grandson improves and shows an upward trend in his school grades. Asthma can be debilitating in many ways.

For more on the rationale behind steroid use for asthma, see my asthma report, which is available by writing: Dr. Donohue - No. 41, P.O. Box 5539, Riverton, NJ 08077-5539. Enclose $3 and a self-addressed, stamped (55 cents) No. 10 envelope.

Question: I am in my 70s, in good health, normally active, but by no means athletic. During a routine health examination, my doctor said my heartbeat was low, like that of an athlete. What is the significance of a low heartbeat?

- N.R.

Answer: Let me substitute "pulse" for "heartbeat." They mean the same.

If your slow pulse is not creating havoc - such problems as fainting or dizziness - then there is no significance in it. Your heart undoubtedly is pumping sufficient blood to keep up with your needs and lifestyle.

Are you taking any medicine that slows the pulse? Some blood pressure medicines work that way.

At any rate, if your heart does not produce signals of mischief, you can forget about it.

By the way, how slow is your heart? You don't say.

Question: What about pneumonia shots? Some seem to need it; others not. Please enlighten us on anti-pneumonia shots. How long is one good for?

- G.A.C.

Answer: Pneumococcal pneumonia is a common infection. The vaccine for it is quite effective, although it won't prevent all lung infections.

Pneumococcal infections kill 40,000 people annually. Most deaths are among the elderly or those with a major illness, such as heart disease or emphysema.

So the vaccine is given to those older than 65 and those suffering from one of the illnesses that in the presence of pneumonia pose special threats.

Protection lasts at least five years and usually as much as 10 years. Revaccination is currently being debated, with more precise recommendations expected soon.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him at P.O. Box 5539, Riverton, NJ 08077-5539.