DEAR DR. DONOHUE: Three months ago I began to take blood pressure medicine. After six weeks, the pressure had come down but not to normal values. The doctor increased the dose of my medicine. Now he wants to add a water pill. Why can’t he put me on a different pill? I have friends who take only one blood pressure pill, and they are fine. – J.S.

ANSWER: Choosing a medicine for blood pressure control is not as simple as it might seem. Doctors want to give their patients a medicine that brings their pressure to the normal range, has the fewest side effects and is the least expensive.

Increasing the dose of one medicine can also increase the chances of intolerable consequences. The doctor wants to use only one medicine as much as the patient wants to take only one medicine. However, the facts of life are that 50 percent to 65 percent of blood pressure patients must resort to using two drugs.

The reason why is that there are so many different blood pressure drugs, and each has its own particular way of lowering pressure. The combination of two drugs, therefore, provides two distinctly different mechanisms for lowering blood pressure. Combinations can often successfully bring the pressure down without incurring the untoward effects that come from increasing the dosage of one medicine.

For example, water pills (diuretics) lower blood pressure by shunting excess fluid into the urine. When the overfilled circulation loses fluid, pressure drops. When the dose can be kept to a minimum, side effects can be kept to a minimum. In the case of diuretics, an increase in the dose might cause the loss of body potassium.

Beta blockers are another class of blood pressure medicines. They bring the pressure down by damping the force with which the heart pumps blood and by slowing the rate at which the heart beats. Increasing their dose could result in such a slow heartbeat that people would be on the brink of fainting.

Combining a beta blocker with a diuretic takes advantage of their two different mechanisms of lowering blood pressure without having to push one drug to such high amounts that side effects are all but guaranteed.

The newly written blood pressure pamphlet takes the mystery out of blood pressure and its treatment. Readers can order a copy by writing: Dr. Donohue – No. 104, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.50 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: On the Internet I read that liquid vitamins are better absorbed by the body than vitamin tablets. Is this true? – D.W.

DEAR DR. DONOHUE: Can you comment on the claim that liquid vitamins are superior to vitamin tablets? – A.A.

ANSWER: There is no credible evidence that liquid vitamins have any advantage over vitamin pills or tablets.

One vitamin tip is worth communicating. It’s best to take vitamins with meals. With food in the stomach, digestive juices and the grinding action of stomach muscles raise their absorption to the maximum.

You don’t have to make a big deal of this. You can take vitamins when it is most convenient for you.

DEAR DR. DONOHUE: When I was growing up, I suffered from what was called growing pains. My mother would massage my legs so I could go to sleep. I don’t hear this spoken of anymore. Don’t children get growing pains today? – R.L.

ANSWER: Bone growth is not painful. Some children — about 18 percent of girls and 13 percent of boys — complain of leg pains that occur at night. In times past, those aches were labeled as growing pains. They are not. Why they happen is inexplicable. Massaging the legs or applying a heating pad to them can generally end the pain and permit the child to sleep in peace.

DEAR DR. DONOHUE: A cardiologist recently examined me. He handed me a card to give to my dentist. It had instructions for antibiotic use before dental work. The card said I had aortic regurgitation. Please explain this condition to me. – L.B.

ANSWER: Aortic regurgitation has another name – aortic insufficiency. That clears the air for readers who know it by the insufficiency name.

The aortic valve is the heart valve that closes after the heart pumps blood. Its closure prevents blood from leaking back into the heart.

Small leaks do not cause big problems. Big leaks do. They make people pant for air when they are up and about. They can also cause breathlessness when people lie in bed.

If the leak is large, the remedy is valve replacement. The doctor keeps a close eye on you to advise you when surgery is advisable. Usually it’s better to schedule valve replacement before symptoms develop. Early surgery prevents permanent damage to the heart. However, all aortic leaks do not call for an operation – only those where the leak is large.

The antibiotic alert protects the leaky valve from infections that could result from dental work that provokes bleeding. In dental procedures that cause bleeding, mouth bacteria can invade the blood and head for the damaged valve.

DEAR DR. DONOHUE: I have lost 50 pounds and have maintained that loss for more than two years. My question regards the calorie content of alcohol. I enjoy a glass of Bailey’s Irish Cream but am hesitant to indulge. I do not want to start putting on weight. – K.W.

ANSWER: Bailey’s Irish Cream is a combination of cream and whisky. The alcohol content is 17 percent (34 proof). One serving yields 117 calories. One hundred seventeen calories are not going to sabotage your weight maintenance program.

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 or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475.