What is the next step for a patient with erectile dysfunction who has an insufficient response to 5 mg of Cialis (tadalafil)?

Management of Insufficient Response to 5 mg Cialis

Increase the tadalafil dose to 10 mg or 20 mg, as the FDA-approved dosing for on-demand use allows titration from the starting dose of 10 mg up to 20 mg or down to 5 mg based on individual efficacy and tolerability. 1

Dose Titration Strategy

The clinician should titrate the tadalafil dose upward to find the optimal dose that meets treatment expectations without unacceptable adverse events. 2

• Start by increasing to 10 mg taken prior to anticipated sexual activity as this is the FDA-recommended starting dose for most patients 1
• If 10 mg is insufficient, escalate to 20 mg, which is the maximum recommended dose 1
• The maximum dosing frequency remains once per day 1
• Tadalafil improves erectile function for up to 36 hours after dosing, allowing flexibility in timing of sexual activity 1, 3

Critical Patient Education Before Dose Escalation

Before increasing the dose, verify that the patient is using the medication correctly, as improper use accounts for a large percentage of treatment failures. 2

Common pitfalls to address:

• Sexual stimulation is necessary for the medication to work 2
• Avoid taking with large meals, which can reduce effectiveness 2
• More than one trial at a given dose may be required to establish true efficacy 2
• An adequate trial is defined as at least 5 separate occasions at maximum dose before declaring treatment failure 2

Alternative Dosing Strategy: Once-Daily Tadalafil

If the patient desires spontaneity without timing medication around sexual activity, consider switching to once-daily tadalafil 5 mg taken at the same time every day, which produces equivalent efficacy to on-demand dosing 2, 4

• Once-daily dosing maintains therapeutic plasma levels continuously due to tadalafil's 17.5-hour half-life 4
• This approach was well-tolerated and effective in long-term studies up to 2 years 5
• The once-daily dose can be started at 2.5 mg and increased to 5 mg based on response 1

Evaluate for Contributing Factors

Check testosterone levels, as testosterone deficiency reduces PDE5 inhibitor effectiveness, and combination therapy with testosterone replacement significantly improves outcomes. 2

Additional factors to assess:

• Review all medications for contributors to ED (antihypertensives, antidepressants, opioids) 2
• Assess cardiovascular risk, as men with cardiovascular disease may have more severe ED 2, 6
• Evaluate for diabetes, as diabetic men respond less robustly to PDE5 inhibitors and may require higher doses 2, 7
• Screen for psychosocial factors (anxiety, depression, relationship issues) that may impair response 2

If Maximum Dose Tadalafil Fails

After an adequate trial of maximum-dose tadalafil (20 mg on at least 5 occasions), try a different PDE5 inhibitor (sildenafil or vardenafil), as individual response varies between agents. 2

• All PDE5 inhibitors have similar efficacy in the general ED population, but individual patients may respond better to one agent 2
• If a second PDE5 inhibitor fails, refer to urology for second-line therapies 2:
  • Intraurethral alprostadil suppositories
  • Intracavernosal injection therapy
  • Vacuum erection devices 2
  • Penile prosthesis (third-line, definitive intervention) 2

Special Dosing Considerations

For patients with renal impairment 1:

• Creatinine clearance 30-50 mL/min: Start with 5 mg, maximum 10 mg once every 48 hours
• Creatinine clearance <30 mL/min or hemodialysis: Maximum 5 mg once every 72 hours