What is the maximum recommended dose of Cialis (tadalafil) for treating erectile dysfunction, including daily dosing recommendations and contraindications?

Maximum Recommended Dose of Cialis (Tadalafil)

The maximum recommended dose of tadalafil for erectile dysfunction is 20 mg taken as needed, not more than once daily, or 5 mg for once-daily dosing. 1

As-Needed Dosing for Erectile Dysfunction

• Start with 10 mg taken prior to anticipated sexual activity, which can be adjusted based on individual response 1
• The dose may be increased to a maximum of 20 mg or decreased to 5 mg depending on efficacy and tolerability 1
• Maximum dosing frequency is once per day in most patients 1
• Tadalafil remains effective for up to 36 hours after dosing, allowing flexibility in timing of sexual activity 1

Once-Daily Dosing for Erectile Dysfunction

• Start with 2.5 mg taken at approximately the same time every day, without regard to timing of sexual activity 1
• The maximum dose for once-daily use is 5 mg, which may be increased from the 2.5 mg starting dose based on individual response 1
• This regimen eliminates the need to time medication with sexual activity, providing an option for couples who prefer spontaneity 2

Once-Daily Dosing for Benign Prostatic Hyperplasia (BPH) or Combined ED/BPH

• The recommended dose is 5 mg once daily for BPH alone or for the combined indication of ED and BPH 1
• This is the only FDA-approved dose for treating both conditions simultaneously 2

Critical Dose Adjustments for Renal Impairment

For as-needed dosing:

• Creatinine clearance 30-50 mL/min: Start with 5 mg, maximum 10 mg once every 48 hours 1
• Creatinine clearance <30 mL/min or hemodialysis: Maximum 5 mg once every 72 hours 1

For once-daily dosing:

• Creatinine clearance <30 mL/min or hemodialysis: Once-daily dosing is NOT recommended for ED alone 1
• Creatinine clearance 30-50 mL/min with BPH or ED/BPH: Start with 2.5 mg, may increase to 5 mg 1

Critical Dose Adjustments for Hepatic Impairment

• Mild to moderate hepatic impairment (Child-Pugh Class A or B): Maximum 10 mg once per day for as-needed dosing; use caution with once-daily dosing 1
• Severe hepatic impairment (Child-Pugh Class C): Tadalafil is NOT recommended 1

Absolute Contraindications

• Tadalafil is absolutely contraindicated with any form of nitrate medication due to risk of potentially fatal hypotension 1, 2
• Patients must avoid nitrates for at least 48 hours after tadalafil use 3, 4
• Riociguat (a soluble guanylate cyclase stimulator) should not be combined with tadalafil due to risk of severe hypotension 5

Important Dosing Considerations

Lack of Dose-Response for Efficacy

• Unlike sildenafil, tadalafil does NOT show dose-dependent improvement in erectile function between 5 mg, 10 mg, and 20 mg doses 2, 4
• The choice between 10 mg and 20 mg should be based primarily on tolerability rather than expecting dramatically better efficacy at higher doses 2

Defining an Adequate Trial Before Dose Escalation

• An adequate trial requires at least 5 separate attempts at the current dose with proper technique before declaring treatment failure or escalating the dose 2, 3
• Many apparent failures are due to inadequate sexual stimulation, improper timing, large meals, heavy alcohol use, or relationship issues rather than true medication inefficacy 2

Common Pitfall to Avoid

• Do NOT increase the dose without first verifying adequate sexual stimulation, proper timing, absence of heavy alcohol use, and addressing modifiable factors such as hormonal abnormalities or relationship issues 2
• Sexual stimulation is necessary for tadalafil to work; the medication does not cause automatic erections 3, 4

Adverse Effects (Dose-Related)

• Higher doses increase the risk of headache, dyspepsia, back pain, myalgia, nasal congestion, and flushing 3, 6
• Most adverse events are mild to moderate and transient 3, 7
• Tadalafil has lower rates of flushing compared to other PDE5 inhibitors 2

Special Populations

• Patients with diabetes or post-prostatectomy have more severe ED at baseline and may respond less robustly to PDE5 inhibitors, but tadalafil remains effective in these populations 2, 4
• For men with testosterone deficiency and ED, combining tadalafil with testosterone therapy may be more effective than tadalafil alone 2

Cardiovascular Risk Assessment Required

• Before prescribing tadalafil, assess whether the patient can perform moderate physical activity (walk 1 mile in 20 minutes or climb 2 flights of stairs) 3
• Patients unable to perform this level of activity should be referred to cardiology before initiating treatment 2, 3