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Лечение аллергии-Allergy treatment

DRUGS THAT RELAX THE PROSTATE: ALPHA BLOCKERS

Remember the two kinds of dssue involved in BPH? One is glandular and is made up of epithelial cells, which secrete fluid that becomes part of the semen. The other is smooth muscle tissue—the stromal cells, whose automatic contractions squeeze this fluid out of the prostate and into the urethra. In BPH, these kinds of tissue act together as a one-two punch: As the glandular tissue enlarges and begins to clog the urethra, the smooth muscle tissue tightens like a fist, and clamps it. But something else is happening with these two kinds of tissue: The balance between them is shifting. In the normal prostate, there are two stromal cells for every epithelial cell; in BPH, it’s five to one. Researchers have described BPH, on a cellular level, as a «stromal process.» In other words, it’s a smooth-muscle problem. And one way to make the passage of urine easier is by taking a drug that relaxes this muscle tissue.

This concept is still relatively new in terms of mainstream drug treatment for BPH (although scientists have been studying alpha blockers and their effect on BPH symptoms for more than fifteen years). But medical researchers have studied smooth muscle tissue, in blood vessels and intestinal walls, for decades. They know, for example, that its actions are involuntary responses to signals from the nervous system. That certain neurotransmitters—chemical messengers which target receptors on the wall of the prostate’s smooth muscle cells— are responsible for making this tissue contract. That other chemical messengers, designed to block these transmitted signals, can make this clenched tissue relax. And that the distribution of these alpha-1 adrenoceptors—they seem to be particularly abundant in the bladder base and prostate—makes alpha-blocking drugs ideally suited for relieving the obstructive symptoms of BPH. The drugs can selectively target and relax muscle cells in the prostate and bladder neck, while ignoring the cells involved in voluntary control of urination.

This promising class of drugs got its start as a treatment for some forms of hypertension, which can involve the same kind of smooth muscle contractions (in blood vessels, not the prostate) as those in BPH. In 1981, the Food and Drug Administration approved an alpha blocker called prazosin (Minipress), for treatment of high blood pressure. Prazosin has a relatively short half-life in the body, and must be taken more than once a day. In 1986, terazosin (Hytrin), an alpha blocker with a longer half-life, was approved by the FDA for treatment of hypertension. Recently, an FDA panel recommended that terazosin be approved for treatment of BPH. Other alpha blockers such as doxazosin (Cardura) are available, and still others are being investigated for use as potential BPH drugs.

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SURGICAL TREATMENTS AND PROCEDURES:PROSTATECTOMY

A century ago, a New York surgeon developed a procedure called «simple,» or «open,» prostatectomy. He reached the prostate through the bladder and used his fingers to remove the overgrown tissue surrounding the urethra, leaving the rest of the prostate intact. (This is not the same thing as a radical prostatectomy, the removal of the entire prostate, which is often used to treat localized prostate cancer.) A refined version of this procedure, which surgeons call suprapubic prostatectomy, is still used today in a small percentage of men with BPH; so is a variation of it called simple retropubic prostatectomy.

But another form of prostatectomy, developed nearly fifty years ago, has eclipsed both operations and is now the main form of surgical treatment for BPH. In this procedure, called transurethral resection of the prostate (TUR; also called a TURP), surgeons reach the prostate by taking a different route— through the urethra. Unlike other forms of prostatectomy, this does not involve a long hospital stay; there’s no incision or scar, and the recovery time is shorter. One major benefit of the TUR—and all forms of prostatectomy—is the opportunity to check the prostate tissue that was removed for cancer after surgery.

The TUR is available to men who otherwise might not be eligible for surgery. About 95 percent of the prostatectomies performed in this country are done transurethrally. And despite the development of new techniques to relieve urinary obstruction, the TUR remains the gold standard for BPH treatment.

However, the TUR is not for everybody. For example, men with large prostates (with obstructive tissue that’s estimated to weigh more than seventy-five grams, or two and a half ounces) probably should have an open prostatectomy. So should some men with large diverticula of the bladder that need to be treated, or men with large bladder stones. (Diverticula are pockets of the bladder lining that poke out like balloons through the bladder wall.) If diverticula or bladder stones need to be removed, this procedure can be «piggybacked» onto (done at the same time as) an open prostatectomy—as surgical «one-stop shopping.»

Nor is the open prostatectomy ideal for every man. The average age of men who have a prostatectomy is 70; by this time in life, many men have other health problems that preclude open surgery—such as a history of heart or lung disease, diabetes, or high blood pressure. For most of these men, and for men with a small prostate, the TUR is the best option. The open prostatectomy is generally reserved for younger men, and those with very large prostates who are otherwise healthy and in good cardiovascular condition.

If your health is considered too precarious even for the TUR, there’s still help—a catheter can provide immediate relief of an overfull bladder, for example. Early studies show intraurethral stents to be a good option for long-term relief of symptoms. Also, you may be able to take medication to shrink the prostate.

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HELP FOR IMPOTENCE AFTER PROSTATE TREATMENT

Men who are impotent after prostatectomy or radiation therapy have normal sensation and normal sex drive, and they can achieve a normal orgasm. Their only trouble may be in achieving or maintaining an erection. And this is a problem that can be fixed.

The purpose of this chapter is not to itemize every possible cause for impotence—there are many—or to discuss every treatment in detail, but to let you know two things: First, that you’re not alone, and second, that help is available.

Here are some statistics: By age 65, about 25 percent of all men are impotent. In the United States, an estimated 10 million men are impotent.

Aging is one reason for impotence. But impotence can also result from medical conditions such as diabetes, hypertension, or multiple sclerosis; from certain medications; from overuse of alcohol, cigarettes or other drugs; even from emotional or psychological problems. For most men, impotence does not have to be a permanent situation. In other words: If there’s a will, there’s generally a way.

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A WORD ON CASTRATION AND IMPOTENCE: WHAT’S REALLY IMPORTANT HERE?

Castration—chemical or otherwise—is an awful thought, one that makes most men shudder. Loss of sexual function or sense of identity is not a pleasant concept; it can be even worse when combined with the fear and uncertainty that are part of having cancer. This is a scary time, but you are not alone. It might help to talk to your doctor, or family, or men who are going through this, too—see the «Where to Get Help» section at the back of this book.

For many men with prostate cancer, when it comes down to choosing between sexual potency and death, the sex life takes a back seat to survival. When hormonal therapy can truly mean the difference between life and death and you’re preoccupied with sexual potency, you’re missing the bigger point.

It’s time for plain speaking again: Get over it. Now is the time to cherish life: Treasure every extra, precious moment you get to spend with your loved ones. Make the most of every day. Now is the time, while you still can, to do the things you’ve always wanted to do—take that trip you’ve always dreamed of, for instance. Take your wife out dancing. Learn to sail. Teach your grandchild how to fish. Realize there is so much more to living than sexual potency.

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EXTERNAL-BEAM RADIATION TREATMENT FOR PROSTATE CANCER: SEXUAL FUNCTION

Sexual potency after external-beam therapy is reported to remain in between 54 percent and 86 percent of men. There is a range here because sexual potency is difficult to measure: Age, stage of disease, and a man’s sex life before treatment all play a role in his ability to have an erection afterward. Men younger than 60, who are sexually active and who are treated when the cancer is in the earlier stages (confined to the prostate) are most likely to remain potent after radiation treatment. However, many men treated with radiation are older, and more likely to have problems with impotence anyway—either because they’re taking medications that can interfere with sexual function, or simply because of their age.

One fact you should know about radiation therapy is that its effect on potency is slower and much more insidious than radical prostatectomy’s more immediate impact. Radiation seems to cause a man’s ability to have an erection to diminish over time (months to years); about half the men who receive it are impotent at seven years after radiation treatment. This is probably because radiation acts on the blood vessels, causing an eventual decrease in blood flow to the penis.

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