Health Care Zone

Prostate drug test inaccurate
This is doubly good news when taken in the context of last October’s USPSTF report, which showed prostate cancer treatments harmed men with impotence and incontinence even when the main blood test used to diagnose it failed to do so accurately.

The new study did acknowledge more drug-related side effects among men given dutasteride than those receiving a placebo: impotence and breast enlargement or tenderness.

Study authors also admit that their findings did not mean that the drug can help slow the progression of high-grade prostate cancer.

The new findings are consistent with the results of previous studies suggesting dutasteride might prevent cancer, notes Dr. Ian Thompson, University of Texas Health Science Center’s prostate cancer expert, who was not associated with the study.

“This study potentially affects 100,000 patients or more annually,” Dr. Thompson said. “For those of us who deal with this disease, this is potentially a big deal.”

Notes of caution
But before you leap off and buy yourself some dutasteride, read these notes of caution:

First, the study was sponsored by Avodart’s maker, GlaxoSmithKline. But the company will not be seeking a formal approval for drug’s use in low-grade prostate cancer management, study author Dr. Fleschner says.

Second, while two previous studies suggested that dutasteride and a similar drug, finasteride, could protect men from prostate cancer, the U.S. Food and Drug Administration said there were still unaddressed concerns these drugs may protect against early cancers but spur the growth of dangerous later-stage ones. The FDA declined requests to allow the drugs to be marketed for cancer prevention.

Third, Dr. Fleschner’s study had limitations: It was small, and three years is a short time to track a cancer that tends to progress over long years. It wasn’t 100 percent blinded, too. While the patients and their doctors were not told who was taking the drug and who was taking the placebo, that was easy to figure out, since dutasteride slashes levels of prostate specific antigen (P.S.A.) in half and blood tests for P.S.A. formed part of the participants’ active surveillance.

The real problem
Two cancer experts say the problem—and solution—rests elsewhere: in the blood tests taken to diagnose prostate cancer.

The problem, they say, may be the extensive prostate screening with P.S.A. tests, which is leading one American man in five to end up with a diagnosis of prostate cancer.

This problem was highlighted by the October 2011 findings of the USPSTF, which was convened to evaluate the controversial P.S.A. tests.

Writing in the editorial accompanying the paper, Dr. Chris Parker of the Royal Marsden, a London cancer center says the solution is to “try to avoid not only treating but also diagnosing low-risk disease.”

In the meantime, he writes, “dutasteride cannot be recommended as an adjunct to active surveillance.”
His views are shared by Dr. Peter Albertsen, a prostate cancer expert at the University of Connecticut.
Dr. Albertsen says he is happy about the new findings but says his enthusiasm for the drug is tempered by worries that dutasteride might fuel the growth of dangerous and deadly prostate cancers.

But the expert, who is not associated with the new study, admits that dutasteride’s effect on P.S.A. levels could be helpful. It might make men taking the drug less likely to worry that their cancer is growing and have biopsies to check, he says.

Side effects
Diagnosed with low-grade prostate cancer and considering taking dutasteride?

Here’s a list of the drug’s potential side effects:
• inability to have or maintain an erection
• decrease in sex drive
• difficulty ejaculating
• breast tenderness or enlargement

Dutasteride may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

Drug interactions
Before taking dutasteride, tell your doctor and pharmacist if you are allergic to dutasteride, finasteride (Propecia, Proscar), or any other medications.

Tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking. Be sure to mention any of the following:

antifungals such as fluconazole, (Diflucan), itraconazole (Sporanox), and ketoconazole (Nizoral); cimetidine (Tagamet); ciprofloxacin (Cipro); clarithromycin (Biaxin); cyclosporine (Neoral, Sandimmune);
danazol (Danocrine); delavirdine (Rescriptor); diltiazem (Cardizem, Dilacor, Tiazac); antibiotics like erythromycin (E.E.S., E-Mycin, Erythrocin); antidepressants like fluoxetine (Prozac, Sarafem); fluvoxamine (Luvox); HIV protease inhibitors such as indinavir (Crixivan) and ritonavir (Norvir); isoniazid (INH, Nydrazid); metronidazole (Flagyl); nefazodone (Serzone); troleandomycin (TAO); verapamil (Calan, Covera, Isoptin, Verelan); and zafirlukast (Accolate).

Dutasteride is only for by men. Women, especially those who are or may become pregnant, should not handle dutasteride capsules because touching the contents of the capsules may harm the fetus. Women who accidentally touch leaking capsules should wash the area with soap and water immediately.

Some dos and don’ts while taking dutasteride:

• Do allow your doctor monitor you carefully for side effects; he may also need to change the doses of your medications.
• Do keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body’s response to dutasteride.
• Don’t donate blood while you are taking dutasteride and for six months after you stop taking this medication.
• Do talk to your doctor about drinking grapefruit juice while taking this medicine.
• Do take a missed dose as soon as you remember it. But if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule.
• Don’t take a double dose to make up for a missed one.
• Do keep this medication in the container it came in, tightly closed, and out of reach of children.
• Do store it at room temperature and away from excess heat and moisture (not in the bathroom).
• Do throw away any medication that is outdated or no longer needed.
• Do tell your doctor and lab personnel that you are taking dutasteride when taking lab tests.

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