DEAR DR. DONOHUE: I am 72 and have a prostate problem, for which I take Hytrin daily. An ultrasound showed prostate enlargement with a weight of 20 grams. The PSA blood test is 0.625. Is there any other medicine that would improve or cure it? Some suggest Proscar. I would like to know any side effects of these medicines. Is my PSA result satisfactory? – K.K.

ANSWER: Symptoms of prostate-gland enlargement include difficulty starting the urinary stream, a weak and slow flow of urine, frequent and urgent needs to empty the bladder, and the necessity of getting up at night to relieve yourself. A large gland, which encircles the urethra – the tube that drains the bladder – obstructs it and causes all the symptoms. I wonder about “large,” because the weight of a normal gland is 20 grams.

There are two classes of medicines used to treat prostate enlargement. One class is called alpha blockers. These medicines relax muscles in the neck of the bladder and in the prostate gland. That opens up urethral obstruction. Hytrin (terazosin) is one such drug. Cardura (doxazosin) is another. Both can lower blood pressure, so they have to be used with caution in men taking other blood-pressure medicines. Flomax (tamsulosin) and the newest alpha blocker, Uroxatral (alfuzosin), do not have the blood-pressure-lowering effect. But the entire class can cause nasal congestion, dizziness, headaches and dry mouth. Side effects happen only to a few. Which is best? That’s a question answerable only through some experimenting.

The second class of medicine shrinks the gland a bit. These medicines interfere with the conversion of testosterone to a more potent hormone that leads to gland enlargement. Proscar (finasteride) is one, and Avodart (dutasteride) is the other. They take a longer time to work – one to six months – and they cause erectile dysfunction in about 4 percent of users. Again, it is impossible to predict if these medicines are better than the other class without trial.

PSA is the screening blood test for prostate cancer. A value of 0.625 is an excellent reading for a 72-year-old man.

DEAR DR. DONOHUE: Have you heard of the Tensilon test for myasthenia gravis? Not many have. – L.D.

ANSWER: In myasthenia, there is a disconnect between muscles and the nerves that activate muscles. For muscle contraction, the nerve must discharge acetylcholine, a chemical that attaches to the muscle and activates it. In myasthenia, there’s not enough acetylcholine to achieve a strong muscle contraction.

Muscle weakness and fatigability are prominent symptoms. Eyelids droop. Chewing and swallowing can be most difficult. Speech is often affected. The arms and the legs become weak.

Tensilon is a medicine that increases the action of acetylcholine on muscle. The doctor injects it into a patient suspected of having myasthenia. If muscle strength is restored with the injection, that is a positive test, one that is strong evidence of the illness. Tensilon is not used for treatment. Its effect is short-lived – around five minutes.

DEAR DR. DONOHUE: I would appreciate an understandable explanation of the factor V Leiden gene mutation, for which I am homozygous. – C.M.

ANSWER: There is an array of proteins in the blood called clotting factors. Some prevent the blood from forming clots when it should not. Others encourage clot formation when there should be a clot – when a vessel breaks.

Factor V (Roman numeral 5) Leiden is a genetic change in one of these clotting factors. When both parents give a child the gene for it, the child is said to be homozygous. The risk of a homozygous person forming inappropriate clots is 80 times greater than it is for the general population. With only one gene (heterozygous), the chance of clot formation is much less.

If a homozygous factor V Leiden patient has had one episode of inappropriate clot formation, that person is put on anticoagulants (blood thinners) for six months. If the patient has a second episode of clot formation, that person is generally kept on anticoagulants for life.

Leiden is a town in the Netherlands where this condition was discovered.

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. Readers may also order health newsletters from www.rbmamall.com.