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

Tadalafil Dosage and Usage for Erectile Dysfunction and Benign Prostatic Hyperplasia

For erectile dysfunction (ED), tadalafil should be started at 10 mg as needed prior to sexual activity, with dose adjustments between 5-20 mg based on efficacy and tolerability, while for benign prostatic hyperplasia (BPH), a daily dose of 5 mg is recommended. 1

Erectile Dysfunction 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 response and tolerability 1
• Maximum frequency: Once per day 1
• Timing considerations: Effective for up to 36 hours after dosing, allowing for greater spontaneity 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 efficacy and tolerability 1
• Advantage: Eliminates need to time medication with sexual activity 3
• Efficacy: Studies show significant improvements in erectile function with daily dosing 3, 4

Benign Prostatic Hyperplasia Treatment

Once-Daily Dosing for BPH

• Recommended dose: 5 mg taken at approximately the same time every day 1
• Efficacy: Significantly improves lower urinary tract symptoms compared to placebo 5, 2
• Duration: When used with finasteride, recommended for up to 26 weeks 1

Combined ED and BPH Treatment

Once-Daily Dosing for Both Conditions

• Recommended dose: 5 mg taken at approximately the same time every day 1
• Efficacy: Studies show significant improvements in both erectile function and urinary symptoms 6
• Advantage: Single medication addressing both conditions simultaneously 6

Special Population Considerations

Renal Impairment

• Moderate impairment (CrCl 30-50 mL/min):
  • For as-needed use: Start with 5 mg, maximum 10 mg every 48 hours 1
  • For 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 every 72 hours 1
  • For daily use: Not recommended 1

Hepatic Impairment

• Mild to moderate impairment:
  • For as-needed use: Maximum 10 mg once per day 1
  • For daily use: Use with caution 1
• Severe impairment: Not recommended 1

Drug Interactions

Important Contraindications and Precautions

• Nitrates: Concomitant use in any form is contraindicated due to risk of severe hypotension 1, 2
• Alpha-blockers:
  • Patients should be stable on alpha-blocker therapy before starting tadalafil 1
  • Combined use requires caution but can be effective for BPH patients 7
  • Combination of tadalafil with alpha-blockers for BPH treatment offers no advantage in symptom improvement over either agent alone 2

Administration Guidelines

• May be taken without regard to food 1
• Do not split tablets; entire dose should be taken 1
• For BPH treatment with tadalafil and finasteride combination, the recommended duration is up to 26 weeks 1

Adverse Effects

• Most common: Headache, dyspepsia, back pain, myalgia, nasal congestion, flushing, and limb pain 2
• Most adverse events are mild to moderate in intensity 5
• Long-term safety studies show tadalafil is well-tolerated for daily use up to 2 years 3

Clinical Pearls

• Tadalafil has a longer half-life (17.5 hours) than other PDE5 inhibitors, allowing for once-daily dosing and greater spontaneity 4
• For BPH patients with concomitant ED, tadalafil 5 mg daily provides a single treatment option for both conditions 6
• Tadalafil is the only PDE5 inhibitor approved for both ED and BPH treatment 5
• Patients should be informed that sexual stimulation is necessary for tadalafil to be effective for ED 2

By following these dosage recommendations and considering individual patient factors, tadalafil can effectively treat both erectile dysfunction and benign prostatic hyperplasia with minimal side effects.