DEAR DR. DONOHUE: Am I crazy, or is it possible that I am very allergic to clindamycin, which I have to take before a dental visit? After taking it, I have a constant bellyache and frequent bowel movements. This lasts for 10 days. (I am 85.) I take no other medication. I do have a heart murmur. This reaction from the medicine keeps me confined. My doctor, druggist and dentist all think I complain too much, but this medicine makes me miserable. What can I do? – Anon.

ANSWER: Clindamycin is a wonderful antibiotic, but it can cause some people the same trouble you describe – stomach upset and diarrhea. You should not use it. It could cause you to have a very serious kind of diarrhea. This isn’t an allergy. It comes about from a different mechanism.

I take it you are given the antibiotic prior to dental work to prevent endocarditis, an infection of the heart and heart valves. Some dental procedures – those that lead to bleeding – allow mouth bacteria to enter the blood. If a person has a slightly out-of-shape heart valve, the bacteria home in on the valve and cling to it. That leads to the endocarditis infection.

I surmise you have a misshapen heart valve, one that is not causing you any trouble but still is a target for blood-borne bacteria, because you say you have a heart murmur. Deformed valves produce heart murmurs.

There are other antibiotics you can take to prevent endocarditis from dental procedures. Amoxicillin and ampicillin (both of which are types of penicillin), cephalexin, cefadroxil, azithromycin and clarithromycin are examples. I don’t know why your doctors don’t want to switch you. You have a valid complaint. I urge you to seek an opinion from another doctor or doctors.

I might have made too many assumptions here, but I believe I am on the right track.

DEAR DR. DONOHUE: A friend who has lens implants in both eyes is experiencing severe macular degeneration and believes the implants have been the cause. Can such a connection be real? I am 82. I have had lens implants in both eyes for 10 years and have recently been diagnosed with early macular degeneration. I wonder if the implants are involved. – D.A.

ANSWER: The macula, a spot no larger than the printed letter o, is at the center of the retina, the backmost layer of the eye. The macula is essential for clear central vision. Any deterioration of it profoundly affects sight.

The lens is in the front of the eye. A clouded lens is a cataract. Today, extraction of a cataractous lens and replacement with an artificial lens is a very common procedure, one that restores vision to many people. In terms of eye distances, the lens is miles away from the retina.

The cause of macular degeneration is unknown. Genes have a great influence, for the process definitely runs in families. Cigarette smoking, having light-blue or light-green eyes, farsightedness (the inability to see clearly up close) and possibly prolonged lifetime exposure to sunlight increase the risk of developing macular degeneration.

I have never read, never heard of and cannot find any relationship between implantation of an artificial lens and the onset of macular degeneration.

DEAR DR. DONOHUE: I started jogging, treadmill running and using step machines nine years ago. Since about five years ago, I have had to breathe harder to get air. My cardiologist diagnosed me with mild mitral valve prolapse. I know what it is, but I don’t know the details. Could the exercise have provoked it? – S.D.

ANSWER: The mitral valve regulates the flow of blood between the upper left heart chamber – the left atrium – and the lower left heart chamber – the left ventricle. A prolapsing mitral valve is one that billows upward into the left atrium when the valve closes.

Exercise does not cause it. Genes do. It’s an inherited condition.

Mild mitral valve prolapse almost never causes any problems. Your heart doctor would have alerted you to any danger if it existed.

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.

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