First-Line Treatment for Erectile Dysfunction
Oral PDE5 inhibitors (sildenafil, tadalafil, or vardenafil) are the first-line treatment for erectile dysfunction unless contraindicated. 1, 2
Mandatory Pre-Treatment Cardiovascular Risk Assessment
Before prescribing any PDE5 inhibitor, you must stratify cardiovascular risk using the Princeton Consensus Panel criteria: 1, 2
High-risk patients (defer treatment until cardiac stabilization): 1, 2
- Unstable or refractory angina
- Uncontrolled hypertension
- Left ventricular dysfunction/CHF (NYHA class II or greater)
- MI or stroke within previous 2 weeks
- High-risk arrhythmias
- Hypertrophic obstructive cardiomyopathies
- Moderate-to-severe valvular disease
Low-risk patients (eligible for all first-line therapies): 1, 2
- Asymptomatic coronary artery disease with fewer than three risk factors
- Controlled hypertension
- Mild, stable angina
- Successful coronary revascularization
- Uncomplicated past MI
- Mild valvular disease
- CHF (NYHA class I)
Absolute Contraindication: Nitrate Use
Never prescribe PDE5 inhibitors to patients taking nitrates—this combination causes potentially fatal hypotension. 2, 3 This is the most critical safety consideration and must be screened for in every patient. 4
Choosing Between PDE5 Inhibitors
All three FDA-approved agents (sildenafil, tadalafil, vardenafil) have equivalent efficacy in the general ED population. 2, 5, 6 The choice should be based on pharmacokinetic differences and patient lifestyle preferences: 2
- Significantly longer half-life (17.5 hours vs. 4 hours for sildenafil/vardenafil) providing a 36-hour window of opportunity
- Ideal for men who prefer spontaneity
- Lower rates of flushing compared to other PDE5 inhibitors
Start with tadalafil 10mg as needed, can increase to 20mg based on response. 3
Ensuring Treatment Success: The 5-Attempt Rule
Before declaring PDE5 inhibitor failure, ensure an adequate trial of at least 5 separate occasions at the maximum tolerated dose. 2 Many perceived failures are due to modifiable factors: 3
- Lack of adequate sexual stimulation
- Incorrect timing of medication
- Food or drug interactions
- Heavy alcohol use
- Undiagnosed hormonal abnormalities
- Relationship issues
Selective Testosterone Testing
Do not routinely measure testosterone in all ED patients. 2 Measure testosterone levels only when patients present with: 2
- Decreased libido
- Premature ejaculation
- Fatigue
- Testicular atrophy
- Muscle atrophy
Lifestyle Modifications
Counsel all ED patients on risk factor modification regardless of pharmacologic treatment: 2
- Smoking cessation
- Weight loss if overweight
- Increasing physical activity
- Avoiding excess alcohol consumption
- Optimal management of diabetes, hypertension, and dyslipidemia
Second-Line Therapies
If PDE5 inhibitors fail after adequate trial, proceed to second-line interventions: 2
Intracavernous injection therapy (alprostadil, papaverine, phentolamine, or combinations) is the most effective non-surgical treatment for ED. 1, 5 The initial trial dose must be administered under healthcare provider supervision. 1
Intraurethral alprostadil suppositories are less invasive than injections but have lower efficacy. 1, 5 The first dose must be administered under healthcare provider supervision due to 3% risk of syncope. 1
Vacuum constriction devices are a non-pharmacological option. 4
Common Pitfalls to Avoid
- Failing to screen for nitrate use before prescribing PDE5 inhibitors 4
- Not performing cardiovascular risk assessment, especially in elderly patients 4
- Declaring PDE5 inhibitor failure without optimizing dosing, timing, and addressing modifiable factors 2, 4
- Overlooking medications that contribute to ED (diuretics, beta-blockers, antidepressants) 4
Safety Profile
PDE5 inhibitors are generally well-tolerated with mild to moderate adverse events: 2, 7
- Headache
- Flushing
- Nasal congestion
- Dyspepsia
- Back pain
- Myalgia
The incidence of serious adverse events is less than 2%, with no significant difference between medications and placebo. 3