The
information in this column is intended for informational
purposes only, and does not constitute medical advice or
recommendations by the author. Please consult with your
physician before making any lifestyle or medication changes, or if you
have any other concerns regarding your health.
VIAGRA & SEXUAL
FUNCTION IN WOMEN
In previous
columns, I have reviewed research studies of female sexual function and
dysfunction (please see my Archives).
This is a very complex area of research, given the large
number of both
biological and behavioral factors at work in human sexuality. Further complicating
matters is the enormous
difference in sexual behavior and physiology between men and women. Male sexual dysfunction,
which most commonly
results from an inability to obtain a satisfactory erection (erectile
dysfunction), is often treatable with Viagra and similar drugs. These medications function
by dilating the
arteries that supplies the erectile tissues in the penis, thus
improving blood
flow to these tissues. In
the absence of
sexual arousal, however, these medications do not have any significant
effect
on erectile function. Because
the
majority of cases of sexual dysfunction in women are related to a
decreased level
of sexual desire, or libido, previous research trials of Viagra, and
similar
drugs, in women have been disappointing, as these medications do not
directly
affect the sexual arousal pathways in the brain.
However,
a new
prospective, double-blinded clinical research trial in the Journal of the American Medical Association
suggests that women who
are experiencing decreased libido associated with antidepressant
medications
may, in fact, benefit from Viagra.
This
study was performed by researchers at the University of New Mexico,
and an important disclaimer has been made by both the study’s authors
and the
Pfizer Corporation, which manufactures Viagra.
Not only was this research conducted with the financial
support of
Pfizer, but several of the study’s authors (including the primary
author) have
a history of receiving funding grants from Pfizer.
Financial
links
between clinical researchers and for-profit pharmaceutical and medical
device
companies are coming under increasing scrutiny by medical ethicists due
to the
obvious potential for conflicts of interest (I often receive offers to
speak on
behalf of such companies, or to participate in research projects with
their
funding, and I have always politely declined such offers from
for-profit
companies). Unfortunately,
due to the
very modest pool of research funding available from governmental and
non-profit
sources, research scientists increasingly find themselves between the
proverbial
“rock and a hard place” when it comes to obtaining sufficient funds to
conduct
their research. In
the case of this
particular research trial, all authors disclosed their fiduciary
relationships
with Pfizer, and Pfizer published a disclaimer indicating that the
company had
no role in the design or conduct of this study, or in the writing of
the
manuscript that resulted from this research.
While these disclaimers do not completely exclude the
possibility of
bias in favor of Viagra by the Pfizer-sponsored researchers, these
public
disclaimers, as well as the randomized double-blinded design of this
prospective clinical trial, represent the most open and honest way of
performing clinical research with a commercial sponsor which is also
the
manufacturer of the drug being studied.
Nonetheless, all research studies that are conducted with
financial
support from commercial entities that have a vested interest in the
outcomes of
such studies should be viewed with a very critical eye.
This
multi-institutional research trial enrolled 98 women with a diagnosis
of major
depression. All of
these women gave a
history of normal sexual desire and function prior to beginning
treatment with
antidepressant medications known as “SRIs,” or serotonin reuptake
inhibitors. (These
medications are known to cause
decreased libido in both men and women as a side effect.) A crucial difference in
this particular
study, when compared to previous research looking at the treatment of
sexual
dysfunction in women with Viagra, is that the women in this study
reported
previously normal sexual function prior to starting treatment with SRI
antidepressant
medications. In
previous Viagra studies,
women volunteers reported decreased baseline sexual desire, and without
any
apparent medical or pharmaceutical causes.
Over
the 8-week
course of this study, half of the women volunteers received Viagra and
the other
half received a sugar pill (placebo) that was identical in appearance
to
Viagra. The women
were instructed to
take their assigned pills just prior to engaging in sexual activity. None of the women
volunteers, or the research
personnel conducting the study, were aware of which pills were Viagra
and which
were placebo pills in this double-blinded study.
Throughout the study, previously validated
female sexual dysfunction surveys were administered to all of the study
volunteers,
and all of the women maintained a personal diary of their sexual
activity. Additionally,
blood levels of female sex
hormones were measured in all of the volunteers.
During
the course
of this study, 22 women (22% of the women who entered the study)
dropped out of
the study for various reasons. However,
the researchers also, appropriately, included these 22 women in their
final
analysis. When the
data was analyzed,
the researchers noted a 60% improvement in sexual function among the
women who
had received Viagra pills (when compared to the patients who had
received the
placebo pills). In
all patients, sex
hormone levels in the blood were within the normal range, and did not
significantly
differ between the women taking Viagra versus those taking the placebo
pill.
Although
this study
is the first ever to find a favorable effect on female sexual function
with
Viagra, it is important to understand that the results of this study
are
probably not applicable to the general population.
Viagra, and related drugs, have no effect on
the areas of the brain that control baseline sexual desire. These drugs work, very
specifically, on the
genitals (and not on the brain).
Therefore, it is not at all surprising that these drugs
have been shown,
by multiple studies, to have no effect on women who are experiencing
decreased
libido that is not due to the side effects of other medications. In this study, however,
women who reported
previously normal levels of sexual desire and function, and who
secondarily developed
sexual dysfunction as a side effect of SRI antidepressants, appeared to
benefit
from Viagra. Because
the mechanisms of
sexual dysfunction are different when comparing primary sexual
dysfunction
versus that caused by SRI medications, Viagra may offer the latter
group of
women an effective therapy by improving genital function.
The
most
important clinical consideration arising from this study is that both
men and
women with major depression frequently stop taking their antidepressant
medications because of the sexual dysfunction that can be induced by
these
drugs. If, indeed,
depressed women can
benefit from Viagra, as men have, then they are more likely to continue
taking
their antidepressant medications.
Nothing in this study contradicts previous studies that
have shown no
benefit from Viagra in women with primary sexual dysfunction. However, for women taking
SRIs for major
depression, Viagra, and similar drugs, may help to reverse
SRI-associated
sexual dysfunction, and may therefore improve compliance with
antidepressant
therapy. This
would, clearly, represent
a “win-win” situation for such patients.
PATIENT-REPORTED
ADVERSE
HOSPITAL EVENTS
In
1999, the
prestigious Institute of Medicine (IOM) estimated that nearly 100,000
Americans
die every year due to medical errors (the vast majority of which
involve errors
in dispensing medications). Although
this report subsequently set off a firestorm of debate regarding the
accuracy
of the IOM’s data and conclusions, there is no doubt but that numerous
injuries
and deaths result, every year, from negligence and errors in medical
and
surgical care. Today,
primarily as a
result of the IOM’s landmark report on medical errors, there is an
enormous
emphasis on improving the quality of care in the United States,
using multiple
approaches to drive down the incidence of preventable medical and
surgical
errors. Currently,
the careful review of
patient medical records is one of the most important methods in use to
detect
evidence of medical errors and patient complications.
A
new research
study, just published in the Annals of
Internal Medicine, offers a sobering assessment of how well
our current
approaches to medical error discovery are functioning, as well as
suggesting
how we might further improve medical error detection.
This study was performed by researchers at Harvard University
and Brown
University.
In
this study,
the medical records of patients who were recently discharged from the
hospital
were randomly selected and reviewed for evidence of medical errors. Additionally, these
patients were contacted
and interviewed, and additional evidence of potential medical errors
was
collected directly from these patients.
The researchers then compared the medical records of these
patients with
the results of patient interviews in an effort to assess how well the
medical
records documented apparent medical errors.
Nearly
1,000
patients participated in this study, and 11% were found to have
experienced at
least 1 adverse event during their hospitalization, based upon a review
of
their medical records. Based
upon direct
patient interviews, however, the researchers determined that at least
23% of
the patients had experienced some sort of adverse event (or events)
during
their hospital stay. Moreover,
many of
these adverse events were not only serious but preventable as well.
Although
the
authors of this study pointed out that patients may not be able to
clearly recall
every in-hospital adverse event when being interviewed months after
discharge, the
findings of this study still raise the very worrisome possibility that
our
current mechanisms of medical error discovery are missing many serious
and
potentially preventable errors. The
results of this study strongly suggest that hospitals should implement
routine
post-discharge interviews of patients as part of the important process
of
identifying medical errors. This
patient-centered
approach may represent a very important new tool in our efforts to
reduce
medical and surgical errors to the lowest achievable level.
CURCUMIN
& PANCREATIC
CANCER
Regular
readers
of this column already know that cancer of the pancreas is a
particularly nasty
type of cancer. More
than 90% of
patients diagnosed with this disease will eventually succumb to it. (Dr. Randy Pausch, the
Carnegie Mellon
Computer Sciences professor who touched the world with his poignant
book, The Last Lecture, died
yesterday of
pancreatic cancer, at the age of 47.)
Currently,
surgery is the mainstay of pancreatic cancer treatment, but the
overwhelming
majority of patients with pancreatic cancer are not candidates for
surgery by
the time their disease has been discovered and diagnosed. Even among the minority of
patients with
pancreatic cancer who are candidates for the radical surgery used to
treat this
dismal disease, the long term survival rates are very poor. Although chemotherapy and
radiation therapy
are often used, particularly in advanced cases of pancreatic cancer,
their
impact on this disease has not been highly effective.
Therefore, a tremendous amount of research is
underway to try and find more effective treatments for one of the most
formidable causes of cancer-related death in the world.
Curcumin
is well
known to connoisseurs of Indian food, as it is a principle component of
tumeric, which is used to make curry.
Numerous laboratory studies have demonstrated that
curcumin has both
anti-cancer and anti-inflammatory activities, and so there is a great
deal of
interest in testing curcumin in humans as an anti-cancer medication. A new study, just
published in the journal Clinical Cancer
Research, examines the
clinical effects of curcumin supplements in patients with advanced
pancreatic
cancer. This study
was performed by
researchers from the University of Texas M.D. Anderson Cancer Center.
In
this study, 21
patients with advanced pancreatic cancer received oral curcumin
supplements,
and were reassessed for response every 2 months during the course of
this
study. In addition
to radiographic
imaging studies of their tumors, blood levels of proteins associated
with both
pancreatic cancer tumor activity and response to cancer treatment were
measured
every 2 months.
In
one patient
who received curcumin, no tumor growth or spread was noted for more
than 18
months, which is remarkable for advanced pancreatic cancer. In a second patient,
curcumin supplementation
was associated with a 73% reduction in tumor size, which is also a
remarkable
response for pancreatic cancer, although this dramatic response was
only
temporary in this patient. Although
the
tumors of the remaining patients did not appear to respond as
dramatically as
was observed in these two patients, the blood levels of proteins
associated
with cancer treatment response revealed a significant biochemical
response to
curcumin supplements in the remaining patients as well.
Why
two patients’
tumors clinically responded, however transiently, so well to curcumin
and the
others did not is unclear at this time.
However, all patients who received curcumin showed
biochemical evidence
of anti-cancer activity in their blood.
Although the overall clinical effects of curcumin in this
early-phase
clinical research study were not very dramatic in absolute terms, the
fact that
any of the patients with advanced
pancreatic cancer in this study experienced any clinical benefit from
this non-toxic
dietary supplement is actually quite remarkable.
In highly lethal cancers, like pancreatic
cancer, which are refractory to most of our treatments, even
incremental
clinical signs of progress, such as were demonstrated in this study,
are cause
for celebration. As
this was only a
small early-phase clinical study, additional and larger prospective,
randomized, double-blinded clinical research trials with curcumin are
warranted, based upon the results of this small study.
Disclaimer:
As always, my advice to readers is to seek the advice of your physician
before making any significant changes in
medications, diet, or level of physical activity.
