[Paleopsych] NYT: (Erections) With New Lease on Life, Don't Miss the Fine Print

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With New Lease on Life, Don't Miss the Fine Print
http://www.nytimes.com/2005/06/21/health/21brody.html?pagewanted=print

    By JANE BRODY

    Only if you never watch television, read a newspaper or magazine or
    listen to comedians can you have escaped the revolution that has
    occurred in the treatment of erectile dysfunction.

    Three drugs - Viagra (sildenafil), Levitra (vardenafil) and Cialis
    (tadalafil) - have in recent years joined several older and more
    invasive or involved treatments for this common condition.

    Estimates of the prevalence vary, ranging from about 5 percent of men
    in their 40's to over 50 percent in their 70's, depending in part on
    how the disorder is defined. An estimated 15 million to 30 million
    Americans have erectile problems.

    But despite the unavoidable exposure to the drugs through advertising
    and comedy routines, a majority of these men have never received a
    medical diagnosis of erectile dysfunction, and only a small fraction
    are being treated, experts report. Many men are too embarrassed to
    mention the problem to their doctors, and many doctors are equally
    reluctant to ask patients about it.

    On the other hand, some men taking the new drugs have not been
    adequately screened for possible correctable underlying causes or
    medical problems that could render the drug treatment unsafe.

    Problem With Many Causes

    A man's ability to perform sexually can be impaired by a host of
    factors, including disorders that affect nerves, blood vessels or
    hormonal output; certain medications (both prescription and over the
    counter); diseases like diabetes, stroke, multiple sclerosis or
    epilepsy; aging; psychological problems like depression and
    performance anxiety; pelvic trauma, radiation or certain operations;
    and, of course, a loss of interest in one's sexual partner.

    In many men with erectile dysfunction, a combination of factors are
    involved.

    Risk factors for cardiovascular disease - hypertension, abnormal blood
    lipids, smoking and diabetes - are associated with an increased
    prevalence of erectile dysfunction, strongly suggesting that men
    seeking treatment first be evaluated for heart and blood vessel
    disease.

    This is best done with a full medical history, measurement of blood
    pressure, blood sugar and blood lipids, and possibly a treadmill test.

    A cardiovascular assessment is especially important for men of middle
    age and older, since resumption of sexual activity after treatment can
    result in a heart attack in those unaccustomed to the exertion.

    Men at high risk for cardiovascular disease - those with uncontrolled
    hypertension, unstable angina, severe heart failure, valve disease or
    who suffered a recent heart attack or stroke - should not engage in
    sexual activity and should not be treated for erectile dysfunction
    until their medical problems are resolved.

    Insufficient testosterone is an uncommon cause of erectile
    dysfunction, affecting about 6 percent of men with this problem.
    Although giving testosterone to someone with a deficiency may not in
    itself correct the erectile problem, testosterone is the libido
    hormone for both men and women and is an important stimulant of sexual
    desire.

    Various Treatments

    The new drugs are revolutionary because earlier treatments were more
    complicated. One very effective agent, alprostadil, must be
    administered directly into the urethra or injected into the penis. The
    injections, which are more effective, can help men with a variety of
    underlying causes, both psychological and physical. In one study, more
    than 80 percent of men and their partners reported satisfactory
    results.

    Another treatment, vacuum constrictor devices, use vacuum pressure to
    promote blood flow into the penis and a constricting ring to keep the
    blood from escaping. Though it works in about two-thirds of cases, it
    does prevent ejaculation.

    A third approach involves an implanted prosthesis. One kind is a
    semirigid rod that, in effect, creates a permanent erection, and the
    other is an inflatable device that can readily pump up the penis when
    sexual activity is desired.

    To appreciate the value of the new drugs, it helps to understand how a
    normal erection occurs. With sexual arousal, the penis must fill with
    blood, causing it to enlarge and become rigid. For as long as arousal
    persists, fibrous tissue in the penis preserves the erection by
    creating a cinch to prevent blood from leaving.

    In addition to a receptive state of mind, adequate levels of
    testosterone and healthy blood vessels and nerves, an erection
    requires the chemical messenger nitric oxide. It plays two critical
    roles, transmitting arousal impulses between nerves, and relaxing the
    smooth muscles in arteries, allowing them to expand and fill with
    blood.

    Nitric oxide signals production within artery cells of a chemical
    called cyclic guanosine monophosphate (cGMP), which increases blood
    flow to the penis. This chemical is broken down by another,
    phosphodiesterase-5 (PDE-5), to end the erection. The new drugs all
    work by inhibiting PDE-5, allowing cGMP to produce and sustain an
    erection.

    The three drugs are about equally effective, but there are differences
    in their actions. In general, the drugs should be taken about an hour
    before expected sexual activity, and none should be used more than
    once a day. Viagra is best taken on an empty stomach (dietary fat
    delays its effect by about an hour).

    Levitra and Cialis are not affected by food, but the blood level of
    Levitra is reduced by high-fat meals. None of the drugs should be
    taken with alcohol, though only Cialis is said to cause dizziness when
    combined with normal amounts of alcohol.

    Viagra and Levitra are effective for about four hours; Cialis, for up
    to 36 hours. Viagra is most effective after an hour. Levitra may work
    within 20 minutes and Cialis within 45.

    It is important for men and their partners to understand that these
    drugs by themselves do not cause an erection or affect libido. They
    work only as a result of sexual stimulation.

    Are the Drugs Safe?

    For men who are otherwise healthy, all three drugs are considered very
    safe. But there can be side effects: headache in 10 to 30 percent of
    patients; flushing in 10 to 20 percent; heartburn in 3 to 16 percent;
    runny nose in 1 to 11 percent; changes in color perception in 2 to 10
    percent; muscle aches and back pain in up to 10 percent; and dizziness
    in up to 5 percent.

    There have also been more than three dozen cases of blindness reported
    in men taking Viagra and four cases in men taking Cialis. The vision
    problem may stem from the same health problem that caused erectile
    dysfunction. Likewise, deaths and nonfatal heart attacks have been
    reported in users, but no cause-and-effect evidence has been shown.

    There are also possible serious interactions with other medications,
    like nitrates (including nitroglycerin pills, patches and pastes);
    alpha blockers for hypertension; protease inhibitors used in AIDS
    treatment; the antifungals ketoconazole and itraconazole; and the acid
    reducer cimetidine.

    Several other drugs, including rifampin, carbamazepine and phenytoin,
    may decrease the effectiveness of the erectile drugs. In addition,
    patients should not take Levitra if they have a heart problem called
    prolonged QT syndrome.

    The erectile drugs come in various dosages, and if a low dose is not
    effective, a higher can often be tried. In men over 65, however, only
    the lowest dosages are recommended.

    Jane E. Brody can be reached at [3]personalhealth at nytimes.com.