Management of Erectile Dysfunction with PDE5 Inhibitors and Apomorphine

Introduction to PDE5 Inhibitors and Apomorphine

The American College of Physicians explicitly recommends optimizing the dose of a single PDE5 inhibitor rather than adding a second agent or combining with other oral ED medications, as combination therapy increases the risk of severe hypotension and other adverse effects without proven additional benefit 2
Both PDE5 inhibitors and apomorphine can cause significant hypotension, particularly when combined with nitrates (which is absolutely contraindicated) 3

Sildenafil and tadalafil are equally effective first-line treatments, achieving 69% success rates for sexual intercourse versus 33-35% with placebo 4
Both agents improve erections in 73-88% of patients compared to 26-32% with placebo 4
An adequate trial consists of at least 5 separate attempts at maximum dose before declaring treatment failure—many apparent failures result from inadequate trials, improper timing, or lack of sexual stimulation 2

Start with sildenafil 50 mg or tadalafil 10 mg as needed, or tadalafil 2.5-5 mg daily for spontaneous activity preference 2, 4
Titrate to maximum tolerated dose (sildenafil 100 mg, tadalafil 20 mg as needed, or tadalafil 5 mg daily) based on efficacy and tolerability 2
Ensure proper use: sexual stimulation required, correct timing (sildenafil 30-60 minutes before, tadalafil up to 36 hours), avoid heavy meals with sildenafil 2

Concurrent nitrate use (oral, sublingual, transdermal, or recreational) due to risk of potentially fatal hypotension is an absolute contraindication to PDE5 inhibitors 3, 2
Wait 24 hours after sildenafil or 48 hours after tadalafil before administering nitrates in emergency situations 3, 2
Refer to cardiology before prescribing if patient cannot perform moderate physical activity (3-5 METs) or has indeterminate cardiovascular risk 3, 2

Do not combine oral ED medications without evidence—polypharmacy increases adverse effects without proven benefit 1, 2
Do not declare treatment failure without ensuring adequate trial parameters (dose, frequency, timing, sexual stimulation) 2
Do not prescribe PDE5 inhibitors without explicitly asking about all forms of nitrate use, including recreational ("poppers") 2