What is the recommended dosage of tadalafil (Cialis) for erectile dysfunction (ED) and benign prostatic hyperplasia (BPH)?

Tadalafil Dosage Recommendations for ED and BPH

For erectile dysfunction (ED), tadalafil should be started at 10 mg as needed (maximum 20 mg) or 2.5-5 mg daily; for benign prostatic hyperplasia (BPH), 5 mg daily is the recommended dose regardless of ED status. 1

Dosing for Erectile Dysfunction (ED)

As-Needed Dosing

• Starting dose: 10 mg taken prior to anticipated sexual activity 1
• Dose adjustment: May be increased to 20 mg or decreased to 5 mg based on efficacy and tolerability 1
• Maximum frequency: Once per day 1
• Timing: Can improve erectile function for up to 36 hours following dosing 1
• Administration: Can be taken without regard to food 1

Once-Daily Dosing for ED

• Starting dose: 2.5 mg taken at approximately the same time every day 1
• Dose adjustment: May be increased to 5 mg based on individual response 1
• Timing: Take without regard to timing of sexual activity 1

Dosing for Benign Prostatic Hyperplasia (BPH)

• Recommended dose: 5 mg once daily, taken at approximately the same time every day 1
• The American Urological Association recommends 5 mg daily tadalafil as a treatment option for LUTS/BPH regardless of ED status 2
• When used with finasteride, the recommended dose is 5 mg daily for up to 26 weeks 1

Dosing for Combined ED and BPH

• Recommended dose: 5 mg once daily, taken at approximately the same time every day 1, 3
• This dosage effectively treats both conditions simultaneously 4

Special Populations and Considerations

Renal Impairment

• Moderate impairment (CrCl 30-50 mL/min):
  • For as-needed use: Start with 5 mg, maximum 10 mg not more than once every 48 hours 1
  • For once-daily use: Start with 2.5 mg, may increase to 5 mg based on response 1
• Severe impairment (CrCl <30 mL/min):
  • For as-needed use: Maximum 5 mg not more than once every 72 hours 1
  • For once-daily use: Not recommended 1

Hepatic Impairment

• Mild to moderate impairment (Child-Pugh Class A or B):
  • For as-needed use: Should not exceed 10 mg once per day 1
  • For once-daily use: Use with caution 1
• Severe impairment (Child-Pugh Class C): Not recommended 1

Drug Interactions

• Absolute contraindication: Concurrent use with nitrates due to risk of severe hypotension 5, 1
• Alpha-blockers: Patients should be stable on alpha-blocker therapy before starting tadalafil, which should be initiated at the lowest recommended dose 1
• Combination with alpha-blockers for BPH: The AUA specifically recommends against combining low-dose daily 5 mg tadalafil with alpha blockers for LUTS/BPH as it offers no advantages in symptom improvement over either agent alone 2

Efficacy and Monitoring

• Allow at least 5 separate occasions at the maximum dose before declaring treatment ineffective 5
• Tadalafil 5 mg once daily significantly improves both ED and BPH-related outcomes 4
• For BPH, tadalafil resulted in significant improvements in IPSS scores compared to placebo 2, 6
• For ED, tadalafil significantly improved IIEF-EF domain scores and successful completion of intercourse 4, 7

Common Side Effects

• Most common: Dyspepsia, headache, back pain, facial flushing, nasal congestion, myalgia 2, 8
• Side effects are generally mild to moderate in intensity 6

Remember that tadalafil tablets should not be split; the entire dose should be taken 1. When properly prescribed and administered, tadalafil is an effective option for managing both ED and BPH symptoms, either separately or concurrently.