BBC: Viagra risks unproven
Thursday, January 21, 1999 Published at 12:48 GMT
Viagra's possible side-effects are well publicised
Almost 200 people around the world have died after
taking Viagra, but it has not yet been proven if the drug
is directly responsible for the deaths.
Some 130 deaths in the US are being investigated. Five
people in the UK and at least 54 others worldwide have
died after taking the drug.
Viagra does have side effects. It carries a warning that it
should not be used in conjunction with nitrate drugs as
combining the drugs could lower blood pressure to
dangerous levels.
Patients who ignore the advice put their lives at risk as
the drug has been linked to sudden death in such
patients with such pre-existing risk factors.
The drug can also affect an enzyme in the retina,
causing a temporary blue visual tinge, and has been
associated with headaches and stuffy noses.
Latest figures
It emerged last weekend that five people had died
following Viagra use in the UK.
Overall it has been linked with 41 cases of adverse
reactions between 1 July and 22 December, according to
figures from the Medicines Control Agency.
The reactions ranged from
skin rashes to major
problems such as heart
attacks.
In 11 cases men taking the
drug suffered heart disorders,
four of whom died. But there
is no indication whether they
already had heart disease or
were taking other drugs for a
heart problem. The fifth death
was a suicide.
In the US, 130 patients are known to have died after
taking drug between late March and mid-November 1998,
according to the Food and Drug Administration.
This figure excluded reports referring to "55 foreign
patients, 35 with unverifiable information (from hearsay,
rumour, the media, or unidentifiable reporters), and 22
with unconfirmed Viagra use".
During the period covered, more than six million
outpatient prescriptions - representing about 50 million
tablets - were dispensed.
Pre-existing conditions
The FDA said 77 of these men died of heart problems,
three had strokes and in the other 48 cases cause of
death was unknown.
The other two cases were accounted for by "homicide
and drowning".
Excluding the last two cases, the patient died within four
to five hours of taking Viagra in 34% of the deaths.
However, most of the patients who died had other risk
factors.
The FDA report says: "Ninety (70%) of the 128 patients
had one or more risk factors reported for cardiovascular
or cerebrovascular disease (hypertension,
hypercholesterolemia, cigarette smoking, diabetes
mellitus, obesity, previous cardiac history).
"Three additional persons without identified heart disease
or risk factors had severe coronary artery disease
detected at autopsy."
The FDA updated the label information for Viagra in light
of these findings
The label for Viagra in the US and in Europe clearly says
that people taking nitrate-based treatments or with
pre-existing heart conditions should not take the drug.
Case histories
In September, the Lancet medical journal reported one
case where it was thought taking Viagra had caused a
heart attack.
The report said that half an
hour after taking Viagra, the
man began to experience
severe chest pains. He has
since made a full recovery.
The researchers, led by Dr J
Feenestra of the Dutch Drug
Safety Unit, said the
65-year-old man's collapse
appeared to have been
triggered solely by taking the
drug.
He had no risk factors for
heart attack and had not even had a chance to test the
much-hyped drug before his collapse.
Dr Feenestra concluded: "The close temporal relation
between ingesting sildenafil [Viagra] and the onset of
severe chest pain due to acute myocardial infarction
[heart attack]...suggests that sildenafil was causally
related."
However, Pfizer, the company that makes Viagra,
accused the Lancet of publicity seeking and said that
the case reported one heart attack in more than three
million users.
Risk factors
Dr Gill Samuels, credited as the inventor of Viagra,
spoke to the BBC in December when it was known that
there had been 69 deaths in the US and a total of 123
worldwide.
She said: "Unfortunately a number of men have died after
taking Viagra. Any death is a tragedy, and we are
always concerned when there are reports of serious
adverse events associated with the use of any of our
pharmaceuticals. But to my knowledge none of these
deaths have been directly attributable to Viagra.
"One thing that we have to remember is that we are
talking about approximately 130 deaths among over
3,000,000 men who have received Viagra.
"Many of them are older and often have another disease
such as heart disease, kidney disease or diabetes.
When you resume sexual activity that can actually place
a strain on the heart. It is exercise and it does increase
cardiac workload."
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