Researchers at the University of Pennsylvania School of Medicine say
preliminary results of a small study show promise in improving
erectile dysfunction (ED) in men who had shown minimal reaction to
Viagra. The study results are published in the March issue of the
"Journal of Sexual Medicine."
Erectile dysfunction is often a sign of a more severe vascular problem
that involves abnormalities in the lining of the blood vessels. And
often, endothelial dysfunction is an underlying problem for ED - it
can be one of the first signs of atherosclerosis, a build-up of plaque
and blockages in the arteries.
"It's already known that there is a connection between erectile
dysfunction and coronary disease. The risk factors are the same for
both, and thus, ED can be a marker for coronary disease," explains
lead author Howard Herrmann, MD, Professor of Medicine and Director of
the Interventional Cardiology and Cardiac Catheterization Laboratories
at the Hospital of the University of Pennsylvania. "Normal erections
are caused when nitric oxide is made, but with endothelial
dysfunction, the body doesn't make enough of it, causing the erectile
dysfunction. Normally, Viagra prevents the breakdown of the little
nitric oxide that is there, so that there is enough of it for an
erection to occur."
However, about 10-30 % of men are classified as "Viagra
non-responders" - in these men, Viagra did not significantly help
their erectile dysfunction. So in a small, double blind, randomized,
placebo-controlled study at Penn, Herrmann looked at a dozen patients
with ED who had not responded well to Viagra. He gave them either a
high-dose Lipitor or a placebo. He then rechallenged them with Viagra
and asked if the ED had improved.
"There did seem to be some improvement for those who received Lipitor
versus the placebo," said Herrmann. "We theorized that if you could
make the edothelium healthier through the use of statins -- so that
there is more nitric oxide available -- you would improve the
endothelial dysfunction and Viagra would work better for the patient."
And there are other potential benefits too. Stan Schwartz, MD,
Director of the Diabetes Disease Management program at Penn and
co-author, states, "Patients with Diabetes, both Type 1 and Type 2,
are plagued with complications of the diabetic state that involve
endothelial dysfunction. This research points us in a direction that
says any drug class that improves endothelial dysfunction may also be
beneficial to patients with diabetes."
Additionally, Emile Mohler, MD, Director of Vascular Medicine at Penn
and co-author, cautions, "ED is a sign that cholesterol plaque may be
present in the heart, neck or leg arteries. Men with ED should be
evaluated for vascular disease."
"These preliminary results show promise," adds Herrmann. "They support
the hypothesis that erectile dysfunction may be one sign of a
generalized vascular disorder characterized by endothelial dysfunction
and that statin drugs may improve the endothelial dysfunction, even
before altering the lipid profile. But the results are preliminary and
warrant further testing in a larger clinical trial," he cautions.
It should be noted that beyond endothelial dysfunction, there are
other reasons Viagra may not work well for someone.
The results of this study were published in the March 2006 issue of
the "Journal of Sexual Medicine." Members can access the journal
on-line at: http://jsm.issir.org/. The article is titled, "Can
Atorvastatin Improve the Response to Sildenafil in Men with Erectile
Dysfunction Not Initially Responsive to Sildenafil? Hypothesis and
Pilot Trial Results."
This study was supported by an unrestricted medical center grant from
Editor's Notes: Dr. Howard Herrmann has received honorarium from
Pfizer and Lilly ICOS. Dr. Stan Schwartz is a consultant and has
received a speaker's honoraria from Lilly ICOS. Dr. Emile Mohler is
part of the speaker's bureau for Pfizer.
To schedule an interview with Dr. Howard Herrmann
please contact Susanne Hartman at 215-349-5964 or
PENN Medicine is a $2.7 billion enterprise dedicated to the related
missions of medical education, biomedical research, and high-quality
patient care. PENN Medicine consists of the University of Pennsylvania
School of Medicine (founded in 1765 as the nation's first medical
school) and the University of Pennsylvania Health System.
Penn's School of Medicine is ranked #2 in the nation for receipt of
NIH research funds; and ranked #4 in the nation in U.S. News & World
Report's most recent ranking of top research-oriented medical schools.
Supporting 1,400 fulltime faculty and 700 students, the School of
Medicine is recognized worldwide for its superior education and
training of the next generation of physician-scientists and leaders of
The University of Pennsylvania Health System includes three hospitals
[Hospital of the University of Pennsylvania, which is consistently
ranked one of the nation's few "Honor Roll" hospitals by U.S. News &
World Report; Pennsylvania Hospital, the nation's first hospital; and
Penn Presbyterian Medical Center]; a faculty practice plan; a
primary-care provider network; two multispecialty satellite
facilities; and home care and hospice.
Contact: Susanne Hartman
University of Pennsylvania School of Medicine