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Erectile
dysfunction: on the efficacy of a phosphodiesteraseinhibitor in patients
with multiple risk factors
Harvey
A. Rosenstock, Samuel D. Axelrad1
University
of Texas Medical School, Houston, Texas, USA
1Baylor College of Medicine, Houston, Texas, USA
Asian J Androl 1999 Dec; 1: 211-214
Keywords:
sildenafil;
impotence; phosphodiesterase inhibitors; multiple
risk factors
1 Introduction
With
the 1998 introduction of sildenafil (Viagra), the first available oral
phosphodiesterase inhibitor, there has been an increased interest in the
treatment of erectile dysfunction (ED), the most common sexual dysfunction
of males. Most experts
estimate that 25 to 30 million men in the United States experience erectile
dysfunction[1]. The
incidence of erectile dysfunction increases with age such that 52% of
all men at some time can expect to experience dysfunction. Successful
treatment of ED has included individual psychotherapy, couples therapy,
and cognitive behavioral therapy, among other modalities.
More recently, the authors have reported a Collaborative Model
which involves both psychiatric consultation with a psychiatrist experienced
in sex therapy and a urologic consultation to insure not only a comprehensive
psychosexual history but a full physical assessment to establish whether
or not organic so-called risk factors are contributing to the etiology
of the ED[2,3,4]. One author has also developed a specific
Cognitive Group Therapy Model for addressing intimacy, erectile dysfunction,
and the integration of the use of a phosphodiesterase inhibitor in the
treatment armamentarium[5,6].
Viagra,
a type of 5 phosphodiesterase inhibitor,
temporarily inhibits the breakdown of cyclic GMP which results
in prolonged relaxation of corpus cavernous smooth muscle and the maintenance
of an erection. Phosphodiesterase
type 5 is an enzyme thought to be primarily found in PDES has been described
in the clitoris, vagina, platelets, the esophagus gastric muscles, and
in some skeletal muscles[9,10]. In the experience of the authors,
for selected patients, the efficacy of concurrent sex therapy with the
prescribing of Viagra has been nearly 100% in terms of self-rated satisfaction
and self-rated grades of erection[9]. The
authors postulate that there would be significantly more patient satisfaction
with concurrent sex therapy.
2 Materials and methods
2.1
Methods
Fifty-five
patients who presented in a large private urological practice were given
a urological examination, and, where clinically indicated, were also given
additional diagnostic studies including Duplex Ultrasonography and a Nocturnal
Penile Tumescence (NPT) study.
These patients were subsequently diagnosed with ED and were clinically
determined to be candidates for a trail on Viagra.
Initially 50 mg of Viagra was prescribed to be taken two hours
before anticipated sexual activity.
This dose was generally titrated to 100 mg to be taken two hours
before anticipated sexual activity.
The patients were treated in a supportive manner.
Their partners were also invited to join in the discussions that
took place at the urological offices.
All
patients were assessed for risk factors.
These risk factors were defined as potential
medical basis for compromised erectile dysfunctioning.
The risk factors for this population included the following:
(1) Diabetes mellitus
(2) Hypertension
(3) Vascular disease
(4) Hypercholesterolemia
(5) Cancer of the prostate
(6) Radiotherapy for cancer of the prostate
(7) Spinal stenosis
(8) Spinal fracture (L2)
(9) Transurethral prostatectomy
(10) Penile implants
These patients were followed for five weeks after which time they were
asked to rate their!satisfaction on a five-tiered subjective scale[12]:
S5: Total satisfaction with the anticipation of being successful all the
time or nearly all the time.
S4: Moderate satisfaction with the expectation of achieving success (good
erection) at least 50% of the time.
S3: Generally satisfied with success expected frequently.
S2: Dissatisfaction with success expected rarely.
S1: Total dissatisfaction with success never expected.
The quality of the erections was also self assessed in accordance with
Boolell's model[7,8]:
G4: Fully rigid penis sufficient for penetration
G3: Penis not fully rigid but adequate for penetration
G2: Penis somewhat rigid but inadequate for penetration
G1: Penis increased in size but no hardness.
2.2
Demographics
3 Results
On
the self-rated satisfaction scale results were as follows:
|
|
Patients |
Percentages |
|
S5 |
21 |
38.18 |
|
S4 |
13 |
23.63 |
|
S3 |
7 |
12.72 |
|
S2 |
7 |
12.72 |
|
S1 |
7 |
12.72 |
Forty-one of the patients were either generally satisfied or almost always satisfied (S5+S4+S3) or 74.5%.
The
results of the patients' self-grading of
the quality of the erection were as follows:
|
|
Patients |
Percentages/% |
|
G4 |
26 |
47.27 |
|
G3 |
21 |
38.18 |
|
G2 |
4 |
7.27 |
|
G1 |
4 |
7.27 |
There
were 47 patients whose erections
were adequate for penetration
(85.45%). Only eight
patients did not receive an erection sufficient for penetration (14.5%).
Two patients had penile implants who were prescribed Viagra. The
first patient was a ED patient for ten years, 57-year-old man who had
an inflatable penile implant for ten years.
During the last five years he developed pain when the implant was
inflated. His satisfaction
with his implant was an S1, although the grade of the erection was G4.
This inflatable implant was removed and replaced with a semi-rigid
prosthesis. This eliminated
the patient's pain and his satisfaction rate was an S2 and the erectile
grade was a G3. With
Viagra (100 mg) the
self-rated satisfaction was an S5 and the grade was a G4.
4 Discussion and summary
The
fact that approximately 75% of the patients were reasonably well satisfied
with the results from Viagra is remarkable given the fact that nearly
65% of the population was characterized by high risk factors.
Further, the fact that 85% of these patients also were able to
obtain grade 3 or grade 4 erection speaks to the efficacy of Viagra. The
authors postulate that those patients whose satisfaction scores were S1
and S2 but who had grade 3 or grade 4 erection would be among those patients
who would especially benefit significantly from concurrent sexual therapy.
There were five such patients.
Based on the experience of working with
patients with erectile dysfunction, the authors also postulate that virtually
all of the patients would have benefited from concurrent sex therapy.
It
was of interest that the two patients with penile implants experienced
much greater satisfaction subjectively when given Viagra.
It is though that this reflects response by the spongiosum of the
glans to Viagra. Also any
remaining corporal tissue may be responsive to Viagra[7,8,13].
There
are a number of significant limitations to this study:
(1) There is no control group; (2) the study is not a double blind
study; and (3) the demographics of
the patients for this study make it difficult to compare to other groups.
The authors support a more extensive prospective study which randomizes
patients with the same average number of risk factors to a trial with
Viagra for erectile dysfunctionwith
one group receiving supportive interactive comments from the treating
physician and one group receiving concurrent brief (25-35 min) sex therapy.
This protocol would be more apt to yield definitive information
with respect to a
Viagra/sex therapy integrative approach for the treatment of ED.
Because of the authors' previous experience with a pilot study
of fifty patients of
whom 33 % had identifiable risk factors who received ongoing brief sex
therapy and who reported 100 % satisfaction and with erection sufficient
for penetration, it appears important to corroborate the positive impact
of sex therapy[11].
Because
Viagra requires the participation of the partner as contrasted with cavernosal
injections, vacuum devices, and intraurethral suppositories, it is more
likely that there will be an increasing number of patients referred to
a sex therapist with the expectation of enhanced intimacy and sexual satisfaction.
This has clearly been the experience of one of the authors (HAR).
Patients
who have had to rely on a cavernosal injections to obtain an erection
have one year dropout of approximately 75%.
Most of the men ultimately complained of inconvenience and cumulative
dissatisfaction. The complaints
associated with cavernosal injection by the patients and their partners
were usually overcome by the positive experience with Viagra.
Nevertheless, it is noted that the 55
patients in this study, 41 absolutely refused cavernosal injection and
12 had had previous experience with cavernosal injections (two patients
had penile implants). Of
the six patients in this study who were treated with Viagra and who had
a subjective satisfaction rating between S1 and S2 and erection grade
between a G1 and a G2, five returned to the self-administration of cavernosal
injections and one returned to the use of a vacuum device.
It appears that the satisfaction level of those patients returning
to cavernosal injections was still relatively low (S1 to S2), but
for idiosyncratic reasons more acceptable.
It is though that those who were more used to cavernosal injections
had developed a routine which was already acceptable
to their partner and ultimately chose not to alter this pattern.
Similarly patients who returned to the use of the vacuum device
were somewhat satisfied and did not see any major advantage in taking
medication. For those
six patients who had low satisfaction ratings and who returned to previous
methods for obtaining erection, there was an average of two risk factors
per patient. Three of the
six patients had poor responses to duplex ultrasonography and one of the
other patients had a poor NPT result.
References
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Correspondence
to Harvey A. Rosenstock, M.D., F.A.C.P., Clinical Associate
Professor of Psychiatry and Behavioral Sciences.
Tel: +1-713-666 3600 Fax: +1-713-666 0987
e-mail: hrosenstoc@aol.com
Received
1999-10-21 Accepted 1999-11-25
