Can daily 5 mg tadalafil improve erectile function in an older man with benign prostatic hyperplasia who has no history of priapism, is not taking nitrates, and has stable cardiovascular status?

Daily 5 mg Tadalafil for Erectile Dysfunction

Yes, daily tadalafil 5 mg significantly improves erectile function in older men with benign prostatic hyperplasia, provided there is no history of priapism, no concurrent nitrate use, and stable cardiovascular status. This regimen offers the dual benefit of treating both erectile dysfunction and BPH-related lower urinary tract symptoms simultaneously. 1, 2, 3

Evidence for Efficacy in Erectile Dysfunction

Daily tadalafil 5 mg demonstrates robust efficacy for erectile dysfunction across multiple high-quality trials:

• In the pivotal FDA registration studies, tadalafil 5 mg once daily significantly improved the International Index of Erectile Function-Erectile Function (IIEF-EF) domain score compared to placebo, with a mean change from baseline of +9.7 points versus +0.9 points with placebo (p<0.001). 2

• Approximately 69% of men using tadalafil reported successful sexual intercourse attempts compared to 33% with placebo, representing a clinically meaningful doubling of success rates. 1, 2

• The Sexual Encounter Profile Question 3 (SEP3), which measures ability to maintain an erection sufficient for intercourse, showed 67% success with tadalafil 5 mg daily versus 37% with placebo. 2

• The treatment effect does not diminish over time—a 6-month double-blind study demonstrated sustained efficacy throughout the entire treatment period. 2

Dual Benefit for BPH and Erectile Dysfunction

For older men with both conditions, tadalafil 5 mg daily is FDA-approved to treat BPH and ED simultaneously, making it uniquely advantageous in this population:

• In men with both ED and BPH, tadalafil 5 mg once daily significantly improved both the IIEF-EF domain score (p<0.001) and the International Prostate Symptom Score (IPSS), with a mean reduction of -6.1 points versus -3.8 points with placebo (p<0.001) at 12 weeks. 2, 3

• Improvements in erectile function were apparent by 3 months, while urinary symptom relief began as early as 2 weeks and reached statistical significance by 4 weeks. 3, 4

• The BPH Impact Index (BII), which measures how urinary symptoms affect quality of life, showed significant improvement with tadalafil 5 mg (p<0.001). 3

• The 2023 European Association of Urology guidelines and the 2018 American Urological Association guidelines both recognize tadalafil 5 mg daily as an effective treatment option for men with BPH-related lower urinary tract symptoms. 5

Special Considerations for Older Men and Comorbidities

Tadalafil remains effective even in populations with more severe baseline erectile dysfunction:

• Men with diabetes mellitus—a common comorbidity in older adults—showed significant improvement in erectile function with tadalafil 5 mg daily, though the magnitude of response was somewhat attenuated compared to the general ED population (mean IIEF-EF change +4.5 points versus +1.3 with placebo, p<0.001). 2

• The FDA label specifically notes that 93% of patients in pivotal trials had ED of at least 1-year duration, and the population included men with multiple cardiovascular comorbidities including hypertension and diabetes. 2

• Tadalafil 5 mg daily has been shown to improve vascular endothelial function in men with BPH, as measured by brachial-ankle pulse wave velocity (baPWV), suggesting potential cardiovascular benefits beyond erectile function. 6

Critical Safety Verification Before Prescribing

Before initiating tadalafil 5 mg daily, you must systematically verify the following absolute contraindications and risk factors:

Absolute Contraindications

• Any history of prolonged priapism (>4 hours) while using a PDE5 inhibitor is an absolute contraindication to tadalafil at any dose, including the 5 mg daily formulation, because prior priapism predicts recurrence and potential permanent erectile tissue damage. 7, 8

• Concurrent use of any nitrate medication (sublingual nitroglycerin, long-acting nitrates, or recreational "poppers") is absolutely contraindicated due to risk of potentially fatal hypotension. 5, 1

• Concomitant use of riociguat (a soluble guanylate cyclase stimulator) with tadalafil is contraindicated because it can cause severe hypotension. 1

Cardiovascular Risk Stratification

The Princeton Consensus Panel criteria must be applied to stratify cardiovascular risk:

• Low-risk patients (who can safely receive tadalafil) include those with asymptomatic coronary artery disease with <3 risk factors, controlled hypertension, mild stable angina, successful coronary revascularization, uncomplicated prior myocardial infarction, mild valvular disease, or CHF (NYHA Class I). 1

• High-risk patients (who should defer PDE5 inhibitor therapy until cardiac condition stabilizes) include those with unstable or refractory angina, uncontrolled hypertension, recent MI or stroke within 2 weeks, NYHA Class ≥II heart failure, high-risk arrhythmias, hypertrophic obstructive cardiomyopathy, or moderate-to-severe valvular disease. 1

• Functional capacity screening: Ask if the patient can walk 1 mile in 20 minutes or climb 2 flights of stairs without symptoms. If unable to perform this level of activity, refer to cardiology before prescribing. 1

Dosing Strategy and Optimization

The daily 5 mg regimen offers distinct advantages over as-needed dosing:

• Daily dosing eliminates the need to time medication with sexual activity, providing an alternative for couples who prefer spontaneous rather than scheduled sexual activity. 1

• Unlike sildenafil and vardenafil, tadalafil does NOT show dose-dependent improvement in erectile function between 5 mg, 10 mg, and 20 mg doses, meaning the 5 mg daily dose provides comparable efficacy to higher doses with potentially fewer side effects. 1

• Sexual stimulation is necessary for tadalafil to be effective—the medication enhances but does not replace natural arousal, and incorrect use accounts for a large percentage of treatment failures. 1

Defining an Adequate Trial

Before declaring treatment failure, ensure the patient has completed an adequate trial:

• At least 5 separate attempts at the prescribed dose with proper sexual stimulation, correct timing (avoiding large or fatty meals), limited alcohol consumption, and realistic expectations. 1

• Systematically evaluate and correct modifiable factors including hormonal abnormalities (low testosterone), concomitant medications that impair erectile function, psychological or relationship issues, and cardiovascular fitness. 1

• Many apparent failures are due to inadequate trials—up to 30% of apparent non-responders become successful responders when modifiable factors are addressed. 1

Adverse Event Profile

Tadalafil 5 mg daily is generally well tolerated, with most adverse events being mild to moderate:

• The most common adverse events are headache (3.7%), back pain (3.1%), dyspepsia, nasal congestion, and myalgia. 2, 4

• Tadalafil has lower rates of flushing compared to other PDE5 inhibitors, which is one of the most bothersome side effects of this drug class. 1

• Serious adverse events occurred in <2% of patients, with no statistically significant difference compared to placebo. 1

• No cases of priapism were reported in randomized controlled trials enrolling thousands of participants for ED or BPH indications. 7

• Higher cumulative doses increase the risk of headache, dyspepsia, back pain, myalgia, and hypotension, though the 5 mg daily dose represents a lower cumulative exposure than as-needed higher-dose regimens. 1

Emergency Nitrate Protocol

If a patient on tadalafil requires emergency nitrate administration:

• Wait 48 hours after the last dose of tadalafil before administering nitrates, under close medical supervision with continuous patient monitoring. 1

• This longer waiting period compared to sildenafil (24 hours) reflects tadalafil's extended half-life (~17.5 hours). 1, 8

Combination Therapy Considerations

For men with testosterone deficiency and ED:

• Combining tadalafil with testosterone therapy may be more effective than tadalafil alone, according to the American Urological Association. 1

• Check total testosterone, free testosterone, and SHBG levels to quantify the degree of testosterone deficiency before declaring tadalafil monotherapy a failure. 1

• Men with testosterone deficiency respond less robustly to PDE5 inhibitors compared to eugonadal men, suggesting a potential benefit from combination therapy. 1

Ongoing Management and Follow-Up

Periodic follow-up should assess:

• Efficacy of treatment and any changes in erectile function. 1

• Side effects and tolerability. 1

• Verification that cardiovascular health status has not changed. 1

• Review of new medications, particularly any that might interact with tadalafil or impair erectile function. 1

• Relationship dynamics and psychosocial factors that influence treatment outcomes. 1