What is the recommended dosage and usage of Tadalafil (Cialis) for erectile dysfunction and benign prostatic hyperplasia?

Tadalafil Dosage and Usage for Erectile Dysfunction and Benign Prostatic Hyperplasia

For erectile dysfunction, tadalafil should be started at 10 mg as needed prior to sexual activity, with adjustment to 5-20 mg based on efficacy and tolerability; for benign prostatic hyperplasia, the recommended dose is 5 mg once daily taken at approximately the same time every day. 1

Erectile Dysfunction (ED) Treatment

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 individual efficacy and tolerability 1
• Maximum frequency: Once per day in most patients 1
• Timing: Can improve erectile function up to 36 hours following dosing 1
• Efficacy: Significantly improves successful sexual intercourse attempts (69% with tadalafil vs 33% with placebo) 2

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
• Advantage: Eliminates need to time medication with sexual activity 3
• Long-term efficacy: Maintains effectiveness for up to 2 years with continued daily use 3

Benign Prostatic Hyperplasia (BPH) Treatment

• Recommended dose: 5 mg once daily, taken at approximately the same time every day 1
• Efficacy: Significantly improves International Prostate Symptom Score (IPSS) compared to placebo 2, 4
• Duration: Improvements in IPSS maintained with continued treatment over a 1-year period 5

Combined ED and BPH Treatment

• Recommended dose: 5 mg once daily, taken at approximately the same time every day 1
• Benefits: Effectively treats both conditions simultaneously 5
• Evidence: Significantly improves both IIEF-EF scores and IPSS when compared to placebo 5

Special Considerations

Renal Impairment

• Moderate impairment (CrCl 30-50 mL/min):
  • As-needed: Start with 5 mg, maximum 10 mg every 48 hours 1
  • Once-daily for BPH: Start with 2.5 mg, may increase to 5 mg based on response 1
• Severe impairment (CrCl <30 mL/min):
  • As-needed: Maximum 5 mg every 72 hours 1
  • Once-daily: Not recommended 1

Hepatic Impairment

• Mild to moderate impairment: Maximum 10 mg once per day; use with caution 1
• Severe impairment: Not recommended 1

Combination with Other Medications

• Nitrates: Absolutely contraindicated due to risk of severe hypotension 1
• Alpha-blockers:
  • Caution is advised due to potential hypotension 6
  • Tadalafil 5 mg should not be combined with alpha-blockers for BPH treatment as it offers no advantage in symptom improvement over either agent alone 2
  • However, recent research suggests that in carefully selected patients, the combination may be safe with minimal hypotensive events 7

Side Effects and Monitoring

• Common side effects: Headache, dyspepsia, back pain, myalgia, nasal congestion, and flushing 2, 8
• Monitoring: Regular assessment of treatment efficacy and side effects 6
• Cardiovascular risk: Assess cardiovascular status before initiating treatment 6
• Warning signs: Patients should report chest pain, severe dizziness, or fainting immediately 6

Practical Tips

• Tadalafil may be taken without regard to food 1
• Do not split tablets; entire dose should be taken 1
• For as-needed use, consider the 36-hour window of efficacy when planning sexual activity 1
• For BPH treatment, consistent daily dosing at the same time is important for optimal effect 1

Tadalafil's unique pharmacokinetic profile with a 17.5-hour half-life makes it particularly suitable for once-daily dosing, offering flexibility for patients with ED, BPH, or both conditions simultaneously 8.