Does anyone have a good feel of how competitive some of the impotence drugs, listed in the Times article, will be in fighting Viagra for market share and who are the companies that make these drugs? The article lists the drugs at the end of the article.
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MEDICINE
APRIL 6, 1998 VOL. 151 NO. 13
Cross-Gender Sex Pill
A new drug designed to treat impotence in men may have
surprisingly similar effects in women
By ARNOLD MANN
rwin Goldstein could hardly wait for the FDA to approve Viagra. The
renowned Boston University urologist is so excited about last week's
approval of the first-ever impotence pill for men that he is opening a new
sexual-dysfunction clinic, and will soon begin prescribing the drug--for
women.
As doctors learn more about the causes of impotence, they're becoming
increasingly convinced that the underlying mechanisms of male and female
sexual dysfunction may not be so far apart. And if that's the case, it's entirely
possible that the same pharmacological science that restores sexual function
to men can work similar magic in women.
Viagra trials in women are already under way in Europe. In April the FDA is
holding an invitation-only meeting of scientists and pharmaceutical executives
to discuss possible testing and use of the drug in women in the U.S. And in
June leading sex researchers will devote their annual meeting in Cape Cod to
discussing how a range of impotence drugs might be tested in female patients.
If the medications prove effective, they could offer women a safer alternative
to the current best weapon against female sexual dysfunction,
hormone-replacement therapy, which carries a slightly increased risk of
cancer. Meanwhile, with the approval of Viagra (release date: mid-April) as
an impotence treatment, doctors will be able to prescribe it "off-label" for
women too. "We intend to use it in women once it's released for men,"
Goldstein says. "Not even a question."
Viagra's effects on the hydraulics of male sexuality are pretty straightforward.
Originally developed as a heart medication, the drug works directly on the
blood vessels, blocking an enzyme called phosphodiesterase. This enzyme
prevents the release of certain neurotransmitters--most notably one called
cyclic GMP--that cause the smooth muscles surrounding arteries to relax,
allowing the arteries to expand. When this occurs in penile arteries, it leads to
engorgement, which leads to erection.
While Viagra doesn't work for every impotent man, it does work for up to
80% of them. "There appears to be no group that has been tested that has a
zero response," says urologist Dr. Harin Padma-Nathan of the University of
Southern California. Even men with the most severe forms of
impotence--spinal-injury victims, diabetics, those who have undergone
prostate-cancer surgery--have responded.
Such results ought to mean good things for women too. Female genitals fill
with blood during sexual stimulation just as male genitals do, resulting in
engorgement of the clitoris and lubrication of the vagina. As women age, they
experience some of the same genital problems men do, as a number of
ailments--particularly atherosclerosis and diabetes--impair blood flow; this
leads to vaginal dryness, pain during intercourse and problems in achieving
orgasm. Indeed, according to one study, more than a third of women in the
18-to-59 age group experience sexual dysfunction, compared with just 10%
of men. "Male sexuality has always been viewed as more important," says
Julia Heiman, a psychologist at the University of Washington and one of the
nation's leading experts on female sexual dysfunction. "A man needs an
erection to have intercourse, so it's easy to regard a man's sexuality as
important and a woman's as sort of an interesting pastime."
How effective Viagra is in women awaits the outcome of the tests. The FDA
and Pfizer, the manufacturer, do not encourage women to use it. "We
strongly recommend against women taking their husband's pills or physicians
using it off-label," says Raymond Rosen, professor of psychiatry at the
Robert Wood Johnson Medical School in New Jersey, who will chair the
Cape Cod meeting.
Still, when it comes to Viagra, some physicians see potential benefits in
careful, off-label use. Goldstein plans to test female patients--mostly
postmenopausal women--for impaired blood flow and give the drug to those
he thinks it can help. He has already received E-mail from women eager to
try it. Other doctors are bracing for the same. "The Viagra avalanche is about
to begin," says Rosen. "Where the oral contraceptive was liberating for
younger people, Viagra may be the sexual-liberation pill of older adults." This
time both men and women will be getting in line.
Impotence Drugs in the Works for Women
--Viagra (chemical name: sildenafil): Relaxes muscle cells to enhance blood
flow. Early female trials under way in Europe; U.S. female trials will be
discussed at an FDA meeting later this month
--Vasomax (phentolamine): Oral version of an approved injectable drug.
Dilates blood vessels to increase flow. Male trials are near completion in the
U.S.; female trials are planned
--Spontane (apomorphine): Works through the central nervous system. Male
trials are nearing completion; female trials are planned
--Prostaglandin creams: Applied to surface of the genitals to stimulate blood
flow. Male trials under way; female trials planned
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Thanks,
Perry |
