Home > Information for doctors >Tutorials Erectile dysfunction.

Author: Francisco Machado
Date 5/12/98

Definition

The consistent inability to achieve or maintain an erection of sufficient rigidity for vaginal penetration in sexual intercourse

Incidence

True incidence is probably higher.

Causes:

 
Psychogenic
Iatrogenic · See below
Neurovascular · Diabetes
· Excess alcohol and obesity
Vascular · Peripheral vascular disease associated with smoking and ageing
· Hyperlipidaemia
· Hypertension
Neurogenic · Spinal cord disease
· MS
· Abdominal and prostatic surgery
Androgen deficiency · Less than 2%

Psychogenic cause more likely if:

· Sudden onset
· Intermittent in nature
· Early morning erections occur
· Associated anxiety or depression
· Relationship problems

But remember that patients with an organic cause will often develop psychological problems as a result.

Assessment.

Six part questionnaire for the assessment of the severity of ED

1. What is the problem with your erections?

- Consider initial firmness and percentage of successful penetrations
- Grade the firmness
- Presence of early morning, spontaneous and nocturnal erections
- Ability to achieve orgasm

2. How long has there been a problem?

- sudden onset suggests psychogenic

3. Do you regard your sex drive as being normal?

- Compared with before?
- Low libido may indicate androgen deficiency but it is more likely to indicate psychological problems

4. What is your partner's attitude towards your problem?

- Allows insight into the relationship
- Is there any performance anxiety and is this primary or secondary

5. What do you think is causing your erections to fail, and have you and your partner done anything about it?

6. What are you and your partner hoping to gain form any treatment s that might be available?

- Gain insight into expectations and whether these are realistic

Iatrogenic causes:

· Central nervous system agents e.g. benzodiazepines and methyldopa
· Antihypertensives e.g. beta blockers and thiazide(20%)
· Anticholinergics e.g. phenothiazines, antidepressants
· Antiandrogens e.g. cimetidine, cyproterone acetate
· LHRH analogues
· Others e.g. NSAIDs, Alcohol, Lipid lowering

Examination:

· BP
· Peripheral pulses
· Examination of genitalia e.g. phimosis, fibrosis, Peyronie's disease
· Lower limb reflexes
· Gynaecomastia
· ? PR

Investigations

· urinalysis
· blood glucose
· consider testosterone if decreased libido
· FSH/LH if low testosterone
· LFT and TFT
· Prolactin
· Cholesterol

Treatment options

Psychosexual counselling

Intracavernous injection therapy

Alprostadil (Caverject)

Prostaglandin E1

· 80% efficacy
· regarded as gold standard

Cost £10 per injection

Contraindications

· clotting tendency
· penile fibrosis
· priapism

Disadvantages

1. high drop out rates (>50% in first year due to:
· recurrence of spontaneous erections
· deteriorating health
· lack of interest
· side effects
· needle phobia

2. Technically difficult

3. Side effects
· Penile discomfort 5-15%
· Bruising <5%
· Priapism (painful erection lasting > 4hrs) <1%
· Long term risk of fibrosis 5-10%

Medicated Urethral System of Injection (MUSE).

Alprostadil pellet

Advantages
· Less threatening
· OK if patient is needle phobic
· Simple
· Efficacy of 50-70%
· Very low risk of priapism

Cost £10

Side effects

· Local discomfort or burning sensation (30%)

Contraindications
· clotting tendency
· penile fibrosis
· priapism
· balanitis and urethritis
· if partner is pregnant a condom is suggested

Oral Therapy

Sildenafil Viagra

Random controlled trials have shown the efficacy of sildenafil to be between 60-90%
There is a dose response relationship in terms of producing and maintaining erection.

The NNT to produce a penetrative erection was about 2 which is the same as for injections and MUSE.

Contraindications

· active bleeding disorder
· concomitant use of oral nitrates

Sildenafil adverse effects: combined studies and doses

 
Adverse effect Placebo (N=382) Sildenafil (N=479) Number needed to harm (95%CI)
Flushing 4 93 5.4 (4.5 to 6.8)
Headache 20 99 6.5 (5.1 to 9.0)
Dyspepsia 7 41 15 (10 to 26)
Visual disturbance 2 22 24 (16 to 49)
Rhinitis 5 24 27 (17 to 69)

 

Mechanical Devices

Advantages

Very cost effective used over a long term period
No risk of drug interactions
70% efficacy in motivated couples

Disadvantages

Initial capital outlay is large (£90-200)
Cumbersome
The erection is cooler and the tension ring may cause pain

Contraindication

Anticoagulant therapy.

Surgery

Now very rarely indicated.

 

Useful references

Wright PL Impotence: the GP's role. Update 8 April 1998 615-624.

Excellent overview from a GP with an interest in ED

Bandolier articles on ED

Erectile dysfunction treatments: Sept 1997 43-3

Erectile dysfunction: July 1998 53-2

BMJ

Gregoire A Viagra: on release BMJ 1998;317:759-760

Smith RViagra and rationing BMJ 1998;317:760-761

 

Comments on this page please to fran@abersychan.demon.co.uk

 

 
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