Viagra
News
Viagra Packages to Include Anti-Counterfeit Tags
Tuesday, 6-Jan-2006
NEW YORK (Reuters) - Pfizer Inc., in a move to thwart counterfeit Viagra, on Friday said it has included special radio frequency identification tags on all packages of its anti-impotence pill to verify they are the authentic Pfizer product.
The world's biggest drugmaker said the new technology, which is difficult and costly to duplicate, would create barriers "for criminals who might attempt to counterfeit our products."
Pfizer has previously also opposed illegal imports of authentic Viagra into the United States, where they can be sold at steeply discounted rates, but said the new technology is not designed to block such imports.
"We honestly have not looked at this from an anti-importation perspective," said Pfizer spokesman Bryant Haskins, whose company has vigorously opposed U.S. legislation that would legalize importation of prescription drugs.
Haskins said the tiny tags are small computer chips that have been affixed to the underside of labels on each bottle of Viagra, as well as on cases and pallets of the drug. The invisible tags relay an electronic code that verifies the product is bona fide and authorized Viagra.
"Pharmacists and wholesalers use specially designed electronic scanners that communicate the code over the Internet to a secure Pfizer Web site" for verification purposes, the New York-based company said.
Haskins said Pfizer is the first large drugmaker to put the radio-tag technology to use but said privately held Purdue Pharma LP already uses such tags to monitor shipments of its widely-abused OxyContin pain drug.
Although the technology can physically scan packages of Viagra and thereby authenticate them, Pfizer said it cannot yet "track and trace" the whereabouts of packages as they are distributed across the United States.
Tracking and tracing would require all parts of the distribution system to invest in compatible technology and agree to use it to share information, Pfizer said.
The company said it plans to further explore tracking and tracing abilities of the technology and how the radio tag technology might also help thwart counterfeit versions of other Pfizer drugs.
Viagra had global third-quarter sales of $386 million, almost half of which were in the United States. Although it remains one of the company's biggest products, Viagra revenue has slipped amid competition from the longer-acting Cialis treatment sold by Eli Lilly and Co.
Pfizer last February filed lawsuits against a number of Web site operators that it alleged have sold illegal versions of Viagra. At the time, Pfizer said it did not know how much the company was losing in Viagra revenue as a result of illegal Internet sales.
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Viagra
prevents anti-cancer drug induced heart damage
Medical Research News
Published: Tuesday, 5-Apr-2005
Virginia Commonwealth University researchers
have found that the popular impotence drug Viagra prevents
damage to the heart from a potent chemotherapeutic agent
frequently used in the treatment of breast cancer, leukemia
and sarcomas.
In the April 5 issue of Circulation: Journal of the
American Heart Association, researchers demonstrated
for the first time that administration of clinically
relevant doses of Viagra, generically known as sildenafil
citrate, one-hour prior to the administration of the
anti-cancer drug doxorubicin (DOX) prevented heart damage
at the cellular level. The research also showed that
the impotence drug also prevented dilated cardiomyopathy
and heart failure in a chronic mouse model. Furthermore,
researchers observed a reduction of DOX-induced cell
death, an improvement of heart function, and a reduction
of electrophysiological abnormalities associated with
heart sickness.
"Our research holds promise for
the potential use of sildenafil in patients receiving
DOX as part of their chemotherapeutic regimen with the
goal of reducing the incidence of DOX cardiomyopathy,"
said the lead author of the study, Rakesh C. Kukreja,
Ph.D., professor of medicine, physiology and biochemistry
at VCU.
"Viagra stabilizes the mitochondria
and protects against free-radical damage of the mitochondria
and heart dysfunction caused by treatment with DOX by
opening the mitochondrial KATP channels in cardiac cells,"
said Kukreja.
Mitochondria are cellular organelles
critical for converting oxygen into ATP, the key fuel
for cellular function. According to Kukreja, free radicals
generated in the mitochondria of cardiac cells by DOX
lead to the break down of regular cellular function,
resulting in programmed cardiac cell death. Over time,
cell death has been linked to decreased heart function
or heart failure.
DOX is an effective chemotherapeutic
agent commonly used in the treatment of many blood and
solid tumor malignancies. Despite DOX's clinical efficacy
for treatment of cancer, its use is associated with
a delayed and progressive cardiomyopathy, often presenting
several years after treatment cessation.
"Viagra is able to protect the
heart from damage that would otherwise disrupt normal
cellular functioning," Kukreja said.
Kukreja and his colleagues began studying
sildenafil in 2002 as part of ongoing research into
"preconditioning," a way to protect the heart
muscle from serious damage in the future by subjecting
it to very brief periods of deprivation of blood flow
and, therefore, oxygen. In papers published in the September
2002 issue of the American Journal of Physiology and
the March 2003 issue of Circulation Research, Kukreja
and his colleagues observed a powerful, protective effect
of Viagra in the heart during experimental heart attacks
in animal models.
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Viagra plus cholesterol drug improves impotence
Journal of Sexual Medicine, March 2006
Lipitor, a commonly prescribed cholesterol-lowering drug, may have extra benefits for men with impotence. Specifically, investigators have found that in men who are not initially helped by Viagra (sildenafil), treatment with Lipitor (atorvastatin) seems to improve sexual response, according to the results of a small study.
Impotence, also referred to as erectile dysfunction, may involve a generalized disturbance of the lining of the blood vessels (endothelium), lead author Dr. Howard C. Herrmann said in a statement. His group therefore theorized that if the endothelium could be made healthier through cholesterol-lowering drugs such as statins -- "Viagra would work better for the patient."
To investigate, Dr. Herrmann, from the University of Pennsylvania in Philadelphia, and colleagues assessed the effect of adding Lipitor to Viagra in 12 men with moderate-to-severe erectile dysfunction despite an adequate course of Viagra treatment. The men were randomly assigned to daily treatment with Lipitor or placebo for 12 weeks.
The researchers' findings appear in the Journal of Sexual Medicine for March.
Treatment with Lipitor, but not placebo, was associated with a significant improvement in the erectile response to Viagra. An effect was seen by six weeks after beginning the trial.
As anticipated, Lipitor also reduced levels of LDL-cholesterol, the "bad" cholesterol, in this case, by 43 percent.
While encouraging, "the results are preliminary and warrant further testing in a larger clinical trial," Herrmann noted.
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FDA
ALERT [07/2005]: A small number of men have
lost eyesight in one eye some time after taking Viagra,
Cialis, or Levitra. This type of vision loss is called
non-arteritic anterior ischemic optic neuropathy (NAION).
NAION causes a sudden loss of eyesight because blood
flow is blocked to the optic nerve.
We do not know at this time if Viagra, Cialis, or Levitra
causes NAION. NAION also happens in men who do not take
these medicines. People who have a higher chance for
NAION include those who:
- have heart disease
- are over 50 years old
- have diabetes
- have high blood pressure
- have high cholesterol
- smoke
- have certain eye problems
FDA has approved new labels for Viagra, Cialis, and
Levitra to include information on possible eyesight
loss (NAION).
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Pfizer
Said Review of All Ocular Event Reports Concludes No
Evidence of Increased Risk of Blindness Among Viagra
Patients NEW YORK, June 27 -- Pfizer Inc said
today that a review of all post-marketing ocular event
reports has concluded that there is no evidence of increased
risk of blindness among patients taking Viagra.
"There is no evidence that Viagra
causes blindness or any other serious ocular condition,"
said Dr. Joseph Feczko, Pfizer's chief medical officer.
"Men taking Viagra are at no greater risk for blindness—including
vision loss from NAION—than men of similar age
and health not taking the medicine."
Pfizer said discussions are progressing
with the U.S. Food and Drug Administration to update
the Viagra label to reflect rare reports of non-arteritic
anterior ischemic optic neuropathy (NAION) in some men
who have used the medicine.
While the FDA concluded that no causal
relationship between Viagra and NAION has been established,
Pfizer has agreed with the agency to include the fact
of these reports in the Viagra label to help inform
physicians and patients. It is Pfizer's understanding
that the FDA has asked that similar information be included
in the labels of all oral ED medicines.
NAION, among the most common acute
optic nerve diseases in older adults, shares a number
of common risk factors with erectile dysfunction: over
50 years of age, high blood pressure, high cholesterol,
and diabetes.
Since Viagra was introduced in 1998,
Pfizer and regulatory authorities around the world have
regularly reviewed all reported adverse events, including
those involving the eye. No regulatory authority has
concluded that Viagra use is associated with an increased
risk for blindness. Most of the reported NAION cases
occurred in Viagra users with underlying anatomic or
vascular risk factors associated with the development
of NAION.
Pfizer has shared this information
with CBS News, which plans to air a story tonight highlighting
reports of blindness with Viagra. Pfizer said it is
concerned that such news reports unnecessarily alarm
patients. "After more than 10 years of rigorous
clinical study and worldwide safety monitoring of a
medicine used by more than 27 million men, there is
no evidence to suggest a link between Viagra and blindness
or other serious ocular events," Dr. Feczko said.
"In addition, several studies specifically looking
into the effect of Viagra in the eye by Pfizer as well
as independent ophthalmologic experts found Viagra to
have no serious adverse effects on the eye."
As with any medication, patients should
consult their physician about use and follow the product's
prescribing information.
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