DEAR DR. ROACH: I am being treated for macular degeneration with injections of Lucentis into the eye. My cardiologist has determined that I have atrial fibrillation and wants to prescribe the anticoagulant Coumadin (warfarin). My non-medical mind senses that these two drugs have opposing functions relative to blood clotting. Am I right? — H.W.

ANSWER: There are two kinds of macular degeneration, and you are being treated for the less-common exudative, or “wet,” type. Lucentis (ranabizumab) works against a protein called human vascular endothelial growth factor A, which is abbreviated VEGF-A. This protein is necessary for new blood vessels to grow. Since growth of new blood vessels is the underlying problem in wet-type macular degeneration, blockers of this protein are effective in slowing progression of the disease. Lucentis is about preventing new blood vessels where they are not wanted.

Warfarin, on the other hand, acts by blocking formation of blood-clotting factors in the liver. This makes abnormal blood clots much less likely, but conversely increases the risk of abnormal bleeding. In atrial fibrillation, where the rhythm of the heart is chaotic, blood clots are likely, and this can lead to stroke, so your cardiologist has looked at your risk factors and recommended warfarin to reduce your risk of stroke.

I can see why you could be concerned about taking both, since these abnormal blood vessels in wet macular degeneration can bleed, and warfarin increases bleeding risk. However, by keeping the warfarin dose adjusted, you can get the benefit of the Lucentis and the reduction of stroke risk without a significant increase in bleeding in the eye. It’s also important to make sure your blood pressure is under control, because that can increase the likelihood of a serious bleed in the eye.

DEAR DR. ROACH: I am an amateur wind instrument player. In the past year I have decided to work hard on my tone quality by playing what are called “long tones.” Among other things, these strengthen one’s embouchure. For a while, I was doing these every day, but then I realized that many or all muscles benefit from cross-training or a rest. Do small muscles of the mouth require cross-training or rest the same way that large weight-bearing muscles (such as those of the arms, legs and back) do? Thousands of wind and brass instrument musicians might be curious about this issue. — M.

ANSWER: All muscles need rest. The small muscles of the mouth, tongue and pharynx that make up the embouchure require less rest than the large muscles in your arms and legs, but it is important for you to rest them if they get to the point of exhaustion.

However, most of training for a musician is about fine neuromuscular control, not so much about muscle strength. For that, hours of training and practice are essential.

The concept of cross-training, by the way, is about gaining cardiovascular and total body fitness by using multiple muscles via different activities. For a musician, that might be analogous to putting down your clarinet and picking up a violin. It might improve your breadth as a musician, but only by practicing your clarinet can you get a more developed clarinet embouchure.

TO READERS: Questions about breast cancer and its treatment are found in the booklet on that subject. To obtain a copy, write: Dr. Roach — No. 1101, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Health newsletters may be ordered from www.rbmamall.com.