For the treatment of male erectile
Sildenafil, an oral phosphodiesterase 5 inhibitor is
‘The treatment of erectile dysfunction, which is the
licensed for the treatment of erectile dysfunction in the
inability to achieve or maintain a penile erection
sufficient for satisfactory sexual performance. In order
for Viagra to be effective sexual stimulation is
Dosage and Administration
The recommended dose is 25-100mg taken orally
Viagra is not indicated for use by women' 1
when required approximately 1 hour before sexualactivity. The maximum recommended dosing
Patients who are taking organic nitrates (or othernitric oxide donors such as amyl nitrite) in any
form, regardless of the frequency, due to a
Sildenafil (primarily at doses of 25-100mg) has been
potentiation of hypotensive effects.
evaluated in approximately 4,000 men with erectile
Men for whom sexual activity is inadvisable.
dysfunction of broad-spectrum aetiology in 21
randomised, double-blind, placebo-controlled, trials of
hypotension (BP < 90/50mmHg), recent history of
up to 6 months duration. Of these 21 studies only 4
stroke or myocardial infarction (MI) and known
have been published in full;5,6,7 11 are available as
hereditary degenerative retinal disorders such as
abstract & posters supported by data in the New Drug
Application (NDA)8 filed with the FDA. Six are only
Patients with a known hypersensitivity to any
available in the FDA-NDA. Data on the remaining
The initial phase II studies measured duration of
Male erectile dysfunction (ED), which is defined as the
penile rigidity, using a Rigiscan, following visual
‘inability to achieve or maintain an erection sufficient
sexual stimulation. Generally an increased duration of
for sexual intercourse’, affects approximately 1 in 10
rigidity > 60% was seen with increasing doses of
sildenafil. The clinical significance of these results isdifficult to quantify.8
The causes of erectile dysfunction are many including;neurogenic or
Sixteen trials evaluated the effect of treatment with
psychogenic (anxiety), hormonal (hypogonadism),
sildenafil (10-200mg) for 4 - 26 weeks on erectile
drug induced (responsible for up to 25% cases), or
function and sexual function in men (>18 years old)
anatomical (peyronies disease) factors. Additionally,
certain diseases predispose patients to erectile
dysfunction, for example up to 50% of men with
Nine trials evaluated fixed doses of sildenafil and 7
diabetes, 40% of men with heart disease and 90% of
allowed dose titration according to response and
men with severe depression, suffer with ED.2,3
tolerability. In the 8 dose titration studies there was a
strong tendency to migrate to the highest dose
Guidelines for the diagnosis and treatment of ED have
available (>50% migrated to 100mg). More than 80%
emphasised the need for a thorough assessment of
of patients completed these studies, data on patient
the problem; a detailed medical and psycho-social
withdrawals were not consistently reported. Generally,
history, clinical examination to elucidate a cause (ED
both treatment-related adverse events and insufficient
can be an early sign of a systemic condition),
response were responsible for <5% of withdrawals.
education of the patient and partner, and inclusion ofthe patient’s needs and preferences in the decision-
In each of the studies significant (p<0.0001)
improvements were apparent with sildenafil treatment
compared to placebo in relation to frequency of
The treatment options available to manage ED
penetration and maintenance of erection after
include psychosexual counselling, hormonal therapy
penetration. Sildenafil treatment, was also associated
(for those with hypogonadism), prosthetic penile
with improved erections (72% vs 18%), an increase in
implants, vacuum devices, vascular surgery, and
successful attempts at intercourse and, where
intracavernosal injection or transurethral therapy with
measured, an improvement in the number of erections
hard enough for intercourse (statistical significance
was inconsistently reported for these variables).
In all cases increasing improvement was apparent over the
of the potential underlying cause of the condition should be
undertaken, before sildenafil treatment is considered.
Sildenafil has been evaluated in approximately 4,000 men
Reduced responses were seen in diabetic men with ED
with ED in 21 randomised double-blind, placebo-controlled
and men with ED post radical prostatectomy. Improved
trials over periods of up to 6 months. Sildenafil 25 - 100mg
erections were only reported in 50-60% and 40-50% of
was effective in approximately 75% of patients, although
lower responses were apparent in diabetic men and those
with ED following a radical prostatectomy.
Patients enrolled in these randomised, double-blind,placebo-controlled trials were entered into open label
Adverse events seen in clinical trials were generally
extension studies. The outcome of these studies is not yet
transient and predictable. Visual abnormalities were noted
particularly at doses above 100mg. There are concerns
regarding the possible long-term consequences of this
Adverse events seen in clinical trials were predominantly
adverse effect. A temporal association with serious
transient, mild or moderate in nature and dose related. Only
adverse events, including MI, has been reported. Sildenafil
2.5% of patients withdrew from sildenafil treatment due to
should not be co-administered with nitrates since large and
an adverse event compared to 2.3% on placebo. The
majority of adverse events seen with sildenafil related to itsknown pharmacological properties; vasodilatation
Careful targeting of the drug to those who require treatment
(including headache, flushing, nasal congestion),
will be essential since it is anticipated that there will be a
gastrointestinal events (dyspepsia) and visual effects
broad market for the drug in men with perceived reduced
sexual functioning in the hope of improving performance.
The Department of Health has issued guidance advising
The adverse effects on vision, reported as light sensitivity
against the prescribing of sildenafil (except in exceptional
and bluish vision lasting from a few minutes to a few hours,
have been recorded particularly at high doses. No effects
on other objective measures of visual function, e.g. visual
1. Anon. Viagra. Summary of Product Characteristics.
acuity, have been reported. Any long-term consequences of
2. Wagner G, de Tejada IS. Update on male erectile
dysfunction. BMJ 1998; 316: 678-682.
No clinically significant changes in blood pressure, heart
3. Holmes S, Kirby R & Carson C. Fast Facts – Male
rate or ECG and no increase in the development of serious
Erectile Dysfunction. Health Press. Oxford 1997.
cardiovascular events were seen with sildenafil in clinical
4. Von Heyden B, Intracavernous Pharmacotherapy for
trials. Sildenafil has not been shown to have a direct effect
Impotence: Selection of Appropriate Agent and Dose.
on platelet aggregation or an effect on sperm motility or
morphology. Priapism has been reported in post marketing
5. Boolell M et al. Sildenafil, a novel effective oral therapy
for male erectile dysfunction. Br.J.Urol.
1996; 37: 257-
During post-marketing surveillance, serious adverse events
including MI, angina, sudden cardiac death and ventricular
6. Goldstein I et al for the Sildenafil Study Group. Oral
arrhythmia have been reported in temporal association with
sildenafil in the treatment of erectile dysfunction.
1998; 338: 1397-1404.
7. Rendell MS, Rajfer J, Wicker PA et al. Sildenafil for
Treatment of Erectile Dysfunction in Men With
Sildenafil is avaliable in three tablet strenghts; 25mg, 50mg
Diabetes. A Randomized Controlled Trial. JAMA
& 100mg. These are provided in packs of 4 and 8 tablets.
The current basic price per tablet is £4.15 for 25mg, £4.84
8. FDA Centre for Drug Evaluation and Research. Joint
for 50mg and £5.88 for a 100mg tablet.
clinical review for NDA-20-895. January 1998.
9. Morales A et al. Clinical safety of oral sildenafil citrate
(Viagra) in the treatment of erectile dysfunction.
ED is currently an under reported condition. The launch of
1998; 10: 69-74.
sildenafil is anticipated to increase the number of patientspresenting with ED. For each patient a careful evaluation
Date: July 2000
THIS SUMMARY SHEET REPLACES SS99/15 WHICH SHOULD BE REMOVED AND DESTROYED
MTRAC, Department of Medicines Management, Keele University
OXFORD ENDOCRINOLOGY MASTERCLASS OXFORD CENTRE FOR DIABETES, ENDOCRINOLOGY AND METABOLISM DISORDERS OF GROWTH AND DEVELOPMENT, THYROID GLAND, APPETITE AND WEIGHT, METABOLISM 12TH-13TH SEPTEMBER 2013 ST CATHERINE’S COLLEGE, OXFORD PROGRAMME THURSDAY 12TH SEPTEMBER 2013 9.15-9.45 Registration and Coffee 9.45-10.00 WELCOME AND MEETING OBJECTIVES
Celebrating 25 Years What do I do if I am drugged? of Survivors’ Strength in 2005 • Get to a safe place and call a family member, Drug Facilitated friend, rape crisis center, hospital, and/or a • If you wish to report the incident, preserve Sexual Assault evidence and do not shower, douche, brush • Seek medical attention for any possible injuries and to be tes