NEW CONCERNS RAISED ABOUT HEALTH EFFECTS OF VIAGRA

BOSTON (Reuters) - The potential health dangers of the
anti-impotence drug Viagra, especially for men with heart problems,
may be more extensive than warnings indicate, said researchers in
Thursday's New England Journal of Medicine.

Letters published in the journal raised new red flags about Viagra for
men with heart trouble and disclosed a possibly fatal lung
complication. Another letter tracked bladder infections in women whose
spouses said they used the drug.

The popular prescription drug is already known to be hazardous to
people with heart disease who take nitrate drugs, such as
nitroglycerin tablets.

But Dr. P.K. Shah of the Cedars-Sinai Medical Center in Los Angeles
describes two men with heart disease and not taking nitroglycerin who
experienced problems after taking Viagra.

One man, 71, had received an implanted defibrillator that delivers a
shock if the heart develops an abnormal rhythm. The man had not
received a shock for six months.

But after taking Viagra and having sex ``he received three shocks,
each a few minutes apart.'' After the third shock, he decided to stop,
said Shah. Tests later showed his heart rhythm had been dangerously
disrupted.

In the second case, a 52-year-old man whose heart had also been
damaged by a heart attack, developed an abnormal heart rhythm after
Viagra-assisted sex. His heart had to be ''shocked'' back to normal.

Shah said caution should be exercised in prescribing sildenafil (the
generic name for Viagra) to men with a history of abnormal heartbeats.

Viagra researchers responded in a letter to the medical journal that
the risk of heart problems rises by 2.5 times in the two hours
following sexual activity. In clinical trials, the rate of chest pains
was the same in men taking Viagra as those who took only a placebo.

Officials with Pfizer declined to comment on the letters, and referred
to the response from the Viagra researchers.

In another letter, Ira Schwartz and Dr. David McCarthy of the
University of Pennsylvania School of Medicine cite a recent study
showing that 31 percent of men with heart disease do not get enough
oxygen to their heart muscle during sex.

Although 7 percent do not experience any chest pain, 24 percent do,
and they might take -- or be given -- nitroglycerin to treat it. They
suggest giving an exercise test to potential Viagra users with heart
disease to help predict which men may be at risk.

The combination of nitroglycerin and Viagra can cause a deadly drop in
blood pressure, as the drug's manufacturer, Pfizer Inc. has warned.

Another letter described an 82-year old man who developed a fatal lung
problem after taking three Viagra tablets over a two-day period. The
letter said that Viagra should be used with care in people who might
be predisposed to lung bleeding.

The Viagra research team said in their letter they were unaware of any
similar lung problems among Viagra users.

A letter from doctors at Newton General Hospital in Covington, Ga.,
reported bladder infections in 15 of 100 women whose spouses received
Viagra.

``Men treated with sildenafil should be advised to tell their female
sexual partners'' to drink plenty of water and empty their bladders
immediately after sex to avoid an infection, they said.

Last month, the Food and Drug Administration reported that it had
identified at least 69 deaths in the United States that might be
linked to Viagra. However, as in the cases cited in the New England
Journal of Medicine, a direct cause-and-effect relationship has not
been established.

Twelve of the 69 men had taken nitroglycerin or some other nitrate
medicine and 18 died during or immediately after sex. Most had some
type of risk factor for heart disease.

The FDA cautioned that ``an accumulation of adverse event reports does
not necessarily indicate that the adverse event was caused by the
drug.'' An underlying disease or some other factor might be
responsible in these cases, the FDA said.

During the first four months Viagra was on the market, more than 3.6
million prescriptions for the drug were filled.

Checked-by: Patrick Henry