For a 56‑year‑old man on a 2000‑mg testosterone pellet who now cannot initiate an erection, is obtaining an electrocardiogram (ECG) and referring to cardiology appropriate, and what further work‑up or treatment should be done?

Erectile Dysfunction Evaluation and Management in a 56-Year-Old Man on Testosterone Pellet Therapy

Your plan to obtain an ECG and refer to cardiology is appropriate, but incomplete—you must first verify his testosterone levels are therapeutic, rule out hypogonadism as the primary cause of his worsening ED, and initiate a PDE5 inhibitor trial before attributing the problem solely to cardiovascular disease. 1

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Immediate Diagnostic Steps

1. Verify Testosterone Replacement is Adequate

• Measure morning total testosterone (8–10 AM) now—the pellet was implanted recently, and you need to confirm he has achieved mid-normal levels (500–600 ng/dL). 1, 2
• If testosterone remains low despite the 2000 mg pellet, the pellet may be under-dosed or poorly absorbed, and his worsening ED could reflect persistent hypogonadism rather than new cardiovascular disease. 1, 3
• Measure free testosterone by equilibrium dialysis if total testosterone is borderline, especially given his likely obesity (common in men receiving pellet therapy). 1, 2

2. Assess for Cardiovascular Risk

• Obtain ECG as you planned—this is guideline-recommended because ED is a sentinel marker for cardiovascular disease, and new-onset inability to achieve erection warrants cardiac evaluation. 1, 4
• Check fasting glucose or HbA1c and lipid profile if not done in the last 12 months—these are mandatory baseline labs for all men with ED. 1, 4
• Measure blood pressure—uncontrolled hypertension is both a cause of ED and a contraindication to certain ED treatments. 4, 5

3. Rule Out Other Organic Causes

• Perform focused genital examination—assess for Peyronie's plaques, testicular atrophy (suggesting primary hypogonadism), and secondary sexual characteristics. 1, 4
• Review his medication list—antihypertensives, antidepressants, and other drugs can cause or worsen ED. 4
• Screen for depression and relationship factors—sudden worsening of ED (from "cannot maintain" to "cannot initiate") suggests either a psychogenic component or acute vascular compromise. 4

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Why His ED Worsened Despite Testosterone Therapy

Testosterone Alone May Be Insufficient

• Only 35–40% of hypogonadal men achieve full erectile restoration with testosterone replacement alone. 6
• A minimal threshold of testosterone is required for PDE5 inhibitors to work—if his testosterone was very low before the pellet, he may have been a "PDE5 inhibitor non-responder" due to hypogonadism. 3, 7
• Testosterone improves libido more reliably than erectile rigidity—his improved mood and energy confirm the pellet is working systemically, but erectile function requires additional intervention in most men. 1

Cardiovascular Disease is the Most Likely Culprit

• ED precedes myocardial infarction by an average of 3–5 years—his sudden inability to initiate erections (not just maintain them) is a red flag for acute vascular insufficiency. 1, 4
• Testosterone therapy does not cause ED, but unmasking of underlying cardiovascular disease can occur as men become more sexually active after starting treatment. 1

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Treatment Algorithm

Step 1: Cardiology Referral (As You Planned)

• Refer to cardiology for exercise stress testing or coronary CT angiography—the Princeton III Consensus recommends cardiac evaluation in men with new-onset ED, especially those with cardiovascular risk factors. 1
• Defer sexual activity until cardiac clearance if he has symptoms (chest pain, dyspnea) or high-risk features (diabetes, hypertension, smoking). 1, 5

Step 2: Initiate PDE5 Inhibitor Therapy (Do Not Wait for Cardiology)

• Start tadalafil 10 mg as needed or 5 mg daily—this is first-line therapy for ED in men with confirmed or suspected hypogonadism, and combining it with testosterone yields superior outcomes. 1, 4
• Sildenafil 50 mg or vardenafil 10 mg are alternatives if cost or patient preference favors them. 1
• Warn him that nitrates are absolutely contraindicated for 48 hours after tadalafil—if he develops chest pain requiring nitroglycerin, he must inform emergency providers he is on a PDE5 inhibitor. 5

Step 3: Optimize Testosterone Levels

• If his testosterone is < 500 ng/dL, consider adding a second pellet or switching to weekly injections—pellets can under-deliver in obese men due to poor absorption. 2, 8
• Target mid-normal testosterone (500–600 ng/dL)—higher levels do not improve erectile function further, but suboptimal levels will prevent PDE5 inhibitors from working. 1, 3

Step 4: Reassess at 12 Weeks

• If ED persists despite therapeutic testosterone and PDE5 inhibitor therapy, refer to urology for intracavernosal injection therapy or vacuum erection device. 1, 4
• If cardiology clears him and ED improves with tadalafil, continue combination therapy indefinitely—most men require both testosterone and PDE5 inhibitors for optimal erectile function. 1, 7

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Critical Pitfalls to Avoid

• Do not assume the testosterone pellet is working without measuring levels—pellets can fail to deliver adequate testosterone, especially in obese men. 2, 8
• Do not delay PDE5 inhibitor therapy while waiting for cardiology—unless he has active chest pain or recent MI, he can safely start tadalafil now. 1, 5
• Do not attribute his ED solely to cardiovascular disease without ruling out persistent hypogonadism—if his testosterone is still low, the pellet is the problem, not his heart. 1, 3
• Do not prescribe nitrates if cardiology finds coronary disease—PDE5 inhibitors and nitrates together cause life-threatening hypotension. 5

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Expected Outcomes

• 60–65% of men respond to PDE5 inhibitors alone, and this increases to >80% when combined with testosterone therapy in hypogonadal men. 1, 7
• If his testosterone normalizes and he receives a PDE5 inhibitor, his erectile function should improve within 4–6 weeks. 1, 6
• If he remains a non-responder, second-line therapies (intracavernosal alprostadil, vacuum devices) have 70–80% success rates. 1, 4