DEAR DR. DONOHUE: Normally, I take Synthroid, Moduretic and Glucotrol daily. I have an aversion to taking all medication at the same time. So I take two of these together on arising, and the third at other times. My reasoning is that some chemicals may conflict with others. Some time back, I questioned my internist on this and he said, "I have never seen this discussed. I suppose you could grind them all together and they would do the job." Does my thinking make sense, or am I too conservative? - W.D.H.

ANSWER: Theoretically, you could take all three medicines at once, so long as they don't upset your stomach. But there's another factor here, which I'll mention later on.The stomach isn't always the scene of problems with multiple drug dosages. Greater problems can occur if the action of one drug is altered by others when they all get into the bloodstream. That's not the case with your three. Your medicines include a diuretic (Moduretic), a thyroid replacement (Synthroid) and a blood sugar control (Glucotrol).

The Glucotrol does raise a different question in itself, and that has to do with timing. Because it bears on blood sugar control, it has to be taken in coordination with your meals and your physical activity. The best time to take it is 30 minutes before a meal to keep blood sugar at normal level.

If you get on a before-meal schedule with the Glucotrol, it doesn't matter when you take the other two, so long as you don't have specific orders regarding them. They won't cause any chemical conflicts in your stomach or elsewhere. But no one advises the grinding up of multiple pills. That was an entirely facetious suggestion.

DEAR DR. DONOHUE: You hear so much about Accutane warnings for women who are pregnant, I was wondering about men taking it. Couldn't a man's sperm be affected and cause birth defects? It seems logical to me, but I haven't seen any reference to this. - J.P.

ANSWER: Accutane does not affect male sperm production in any way. Accutane is used for severe cases of acne. Accutane, when used by a pregnant woman, can cause very serious fetal malformations.

Any damage from Accutane occurs to the developing baby, not prior to conception. Hence, sperm is not involved in the problem.

DEAR DR. DONOHUE: I would like information relative to intravenous pyelogram. What is it? What is its function? Is it painful? What about risks? Does it cause prostate enlargement? - A.V.M.

ANSWER: If you want to get really good X-ray pictures of many body organs you have to make its tissue pop out in contrast to neighboring tissue and organs. Otherwise, things are too fuzzy. An intravenous pyelogram (IVP) does just that for the kidney and urinary bladder.

"Pyelogram" refers to the area targeted, the kidneys. "Intravenous" means only that a dye is injected into one of your veins. Radiologists cringe when I use the term "dye," much preferring that I call it "contrast medium." I offer readers their choice.

Whatever you call it, the substance is taken to the kidney in the blood and is there deposited. It "lights up" that organ for subsequent X-rays.

For the many questioners with your concerns, IVP is a safe procedure. It is not painful. It does not take long, and you go home as soon as the pictures are taken. It does not do anything to the prostate gland, which is far from the scene of the action anyway. Only rarely will a person have a reaction to the dye. If so, steps are taken to counter it.