HERBAL PROSTATE DRUG GOES MAINSTREAM
HEALTH SENSE / JUDY FOREMAN
Judy Foreman is a member of the Globe staff. Her e-mail address is: foreman(at sign)globe.com.
If you're male and you live long enough, there's virtually no escaping the indignities and agonies of an enlarged prostate.
In young men, this gland, which surrounds the urethra (the tube through which urine passes) and is the size of a chestnut, secretes part of the seminal fluid that nourishes sperm and speeds it on its way.
But over the years, assuming a man has normal levels of the hormone testosterone, the prostate enlarges -- sometimes to the size of a grapefruit -- and presses on the urethra. This causes incomplete emptying of the bladder, the need to urinate often and urgently, a weak ``stream'' and -- most annoying -- the need to get up frequently at night to urinate.
For one in three men, benign prostatic hyperplasia, or BPH, gets bad enough to warrant medical intervention -- prescription drugs or one of several types of minimally invasive surgery.
Increasingly, however, men are using herbal remedies instead of or in addition to the traditional treatments -- mainly preparations of saw palmetto but also pumpkin seeds, nettle roots, Swedish pollen, and Pygeum africanum, the bark of an African tree.
The question is, should they?
The answer is a cautious yes, with an important caveat. As with every other product on the $4 billion-a-year herbal market, these ``botanicals'' are not reviewed by the US Food and Drug Administration. That means it's difficult to know how truly safe or effective they are.
On the other hand, there is a growing body of evidence -- albeit small, flawed studies -- that suggests that saw palmetto, at least in some preparations, is safe, has few side effects, and may relieve BPH symptoms. Data on the other herbal BPH remedies, however, are scant.
Saw palmetto extract, which comes from the berries of a dwarf palm tree, is "one of the better'' herbal products, says plant medicine researcher Varro Tyler, dean emeritus of the Purdue University School of Pharmacy and Pharmacal Sciences.
In a recent editorial in the journal Urology, Tyler and Dr. Leonard S. Marks, a UCLA urologist, noted that one large study showed a saw palmetto brand called Permixon (sold in Europe) is safe and causes no changes on standard blood tests, including PSA tests.
(The PSA, or prostate specific antigen, test is used to detect prostate cancer, and doctors had feared that saw palmetto might alter PSA scores, making it harder to detect cancer.)
And, Permixon is as effective as and less likely to cause impotence than Proscar, a prescription drug often used to treat BPH, according to a 1996 study of 1,098 men.
But Permixon, which is not available in the United States, is relatively easy to study because it contains no other ingredients.
By contrast, many of the 30-odd preparations available on store shelves in this country contain a mish-mash of ingredients, making it impossible to know what agent is doing what.
"Permixon is very highly purified,'' and very safe, says Dr. John McConnell, a University of Texas urologist who heads a committee of the American Urological Association charged with assessing treatments, including herbals, for BPH.
"God knows what's in these other preparations. Each one would have to be evaluated'' separately, he says. "It boggles the mind how one would test that.''
That said, a 1998 analysis of pooled data from 18 studies involving 2,939 men nevertheless concluded that saw palmetto, in a number of different preparations, does seem to be better than placebo in relieving BPH symptoms. This analysis of saw palmetto (also called serenoa repens) was published last November in the Journal of the American Medical Association.
Curiously, nobody really knows how it might work. One hypothesis is that it may affect hormone levels, but the lack of side effects, such as decreased libido, argues against this.
What it may do, though again it's not clear how, is shrink prostate tissue. At a meeting of the American Urological Association in May, Marks reported on his double-blind study of 41 men who had biopsies (or tissue samples) of their prostates taken at the beginning and end of a 6-month period.
He found a reduction in prostate size in men who took a saw palmetto and nettle root preparation made by Nutrilite compared to those in men who took a placebo, or dummy drug.
Marks' team suspected the herbal remedy might act by inducing cell death or blocking blood-vessel growth in prostate tissue, but neither of those hypotheses panned out, he says, suggesting that it may work through some still-unknown ``novel mechanism.''
The Marks study, in which men taking saw palmetto reported about the same level of improvement in clinical symptoms -- 25 percent -- as those on placebo, highlights another conundrum of prostate research: Many remedies, even prescription drugs, seem to be only partially effective, and many patients taking placebos report a mild improvement in symptoms, too.
In fact, overall, about 50 percent of men who get a placebo in BPH drug studies say their symptoms get better, perhaps through the expectation of improvement, notes Dr. Kevin R. Loughlin, director of urological research at Brigham and Women's Hospital in Boston.
It's common for men to give ``mixed reviews'' to both herbal remedies and prescription drugs for BPH, says Dr. Isadore Rosenfeld, a cardiologist at the Weill School of Medicine at Cornell University in New York City and author of several books on alternative medicine.
With saw palmetto, he says, "some men say yes, it helps, others say no. It's the same with Proscar,'' the prescription drug, which can take three to six months to take effect, he says.
Les Hellenack, 70-year-old Watertown computer consultant who's been taking both saw palmetto and Proscar for more than five years, puts it this way:
"I can't tell which is helping, but between them, they both seem to help.''
The gradual enlargement of the prostate gland with age is "the most common benign disease of mankind,'' says Dr. Kevin R. Loughlin, director of urologic research at Brigham and Women's Hospital in Boston.
And while many men now try to treat it with herbal remedies, many still prefer the traditional therapies, for which there are considerably more data. Some combine both approaches.
Although benign prostatic hyperplasia, or BPH, does not lead to prostate cancer, both BPH and prostate cancer are hormone-driven. Testosterone drives prostate cancer. A hormone called DHT, or dihydrotestosterone, made from testosterone, drives BPH.
Several types of prescription drugs are used to treat BPH. For mild cases, doctors often use ``alpha blocking'' drugs such as Hytrin, Cardura or Flomax that improve urination by relaxing the muscles in the urethra, the tube through which urine flows. Hytrin and Cardura are also used to treat high blood pressure, and in some men being treated for prostate problems, may cause a sharp drop in pressure.
For men with more advanced BPH, a drug called Proscar, which blocks the conversion of testosterone to dihydrotestosterone, can help. In theory, because Proscar blocks DHT but not testosterone itself, libido and potency are not affected, but in practice, some men taking Proscar do encounter these side effects.
Proscar can also muddy the results of the PSA, or prostate specific antigen, test used to detect prostate cancer. (The PSA test is imperfect to begin with: a high score may indicate cancer, BPH or even just a prostate infection; conversely, a man can have cancer, BPH or an infection with a normal score.)
After several months on Proscar, PSA levels often drop by half. In general, a normal PSA score is 0 to 4 (nanograms per milliliter); but age counts, so this is often refined so that normal for a man in his 40s is 0 to 2.5; in his 50s, 0 to 3.5, in his 60s, 0 to 4.5 and in his 70s, 0 to 6.5.
If a man takes Proscar and his PSA score drops, his doctor should mentally double the score so as not to underestimate the risk of prostate cancer, Loughlin says.
If drugs fail, four surgical options are available:
- TURP, or transurethral resection of the prostate. With the patient under regional or general anesthesia, the surgeon inserts a cystoscope (viewing instrument) into the urethra. A wire-like scoop at the tip is then pushed through into surrounding tissue. This takes about an hour and can cause bleeding. After healing, a man can have normal sex, including orgasm, but usually has retrograde ejaculation, in which sperm flows backward into his bladder, which is not harmful. A TURP has excellent longterm efficacy: 7 years later, 80 to 90 percent of men still have relief from BPH.
- Laser TURP. This is like a regular TURP except that laser energy, delivered through a fiber optic tube, is used to destroy prostate tissue. The laser heats tissue, causing it to contract over several weeks. The surgery takes 20 minutes and causes less bleeding than a standard TURP and less likelihood of retrograde ejaculation. But longterm efficacy has not been proved.
- TUNA, or transurethral needle ablation. This is like a laser TURP except that radiofrequency energy is used instead of lasers. And unlike a TURP, the surgeon does not operate through a viewing tube, so the procedure is ``blind.'' Longterm efficacy has not been proved.
- TUMT, or transurethral microwave therapy. This is like TUNA, except that microwave energy is used to destroy prostate tissue. Longterm efficacy has not been proved.