What is the recommended dose of Cialis (tadalafil) for erectile dysfunction?

Recommended Dosing of Cialis (Tadalafil) for Erectile Dysfunction

For erectile dysfunction, tadalafil (Cialis) should be started at 10 mg taken prior to anticipated sexual activity, with dosing adjustments between 5-20 mg based on individual response and tolerability. 1

On-Demand Dosing

• The FDA-approved starting dose for on-demand use is 10 mg taken prior to anticipated sexual activity 1
• The dose may be increased to 20 mg or decreased to 5 mg based on individual efficacy and tolerability 1
• Maximum recommended dosing frequency is once per day 1
• Tadalafil can improve erectile function for up to 36 hours following dosing, allowing flexibility in timing of sexual activity 1, 2
• Most men take advantage of this extended duration by attempting intercourse both at early (1-4 hours) and later (12-36 hours) intervals after taking the medication 2

Once-Daily Dosing Option

• The recommended starting dose for once-daily use is 2.5 mg, taken at approximately the same time every day 1
• The dose may be increased to 5 mg based on individual efficacy and tolerability 1
• Daily dosing eliminates the need to plan sexual activity within a limited timeframe 3, 4
• Once-daily dosing of 2.5 mg and 5 mg has been shown to be well tolerated and significantly improve erectile function 5, 4
• This regimen provides an alternative for couples who prefer spontaneous rather than scheduled sexual activity 3

Special Population Considerations

Renal Impairment

• For on-demand use in patients with creatinine clearance 30-50 mL/min: 5 mg starting dose, maximum 10 mg not more than once every 48 hours 1
• For on-demand use in patients with creatinine clearance <30 mL/min: Maximum 5 mg not more than once every 72 hours 1
• Once-daily use is not recommended for patients with creatinine clearance <30 mL/min 1

Hepatic Impairment

• For mild to moderate impairment (Child-Pugh Class A or B): Maximum 10 mg once per day 1
• For severe impairment (Child-Pugh Class C): Use not recommended 1

Efficacy and Safety

• PDE5 inhibitors including tadalafil have high efficacy rates (73-88%) compared to placebo (26-32%) 3
• Common adverse effects include headache, dyspepsia, back pain, myalgia, nasal congestion, and flushing 3, 6
• Tadalafil tends to have lower rates of flushing compared to other PDE5 inhibitors 3
• Long-term studies show tadalafil is safe and well-tolerated for extended periods (up to 24 months) 6
• The rate of discontinuation due to adverse events in long-term studies is approximately 6.3% 6

Important Clinical Considerations

• Tadalafil may be taken without regard to food 1
• Patients with diabetes may benefit from tadalafil, with once-daily dosing of 2.5 mg and 5 mg shown to be efficacious in this population 7
• Patients with testosterone deficiency should be informed that combining testosterone therapy with tadalafil may be more effective than tadalafil alone 3
• Use of tadalafil with nitrates is contraindicated due to risk of significant hypotension 3
• Incorrect use (lack of sexual stimulation, taking with large meals) accounts for many treatment failures, so proper patient education is essential 3

Dosing Algorithm

1. For most patients, start with 10 mg on-demand dosing
2. If inadequate response, increase to 20 mg
3. If side effects occur, decrease to 5 mg
4. For patients preferring spontaneous rather than planned sexual activity, consider once-daily dosing starting at 2.5 mg and increasing to 5 mg if needed
5. For patients with renal or hepatic impairment, follow the reduced dosing guidelines outlined above