What is the recommended dose of Tadalafil (Phosphodiesterase type 5 inhibitor) for erectile dysfunction?

Recommended Dosage of Tadalafil for Erectile Dysfunction

For erectile dysfunction, tadalafil can be prescribed as either 10 mg taken as needed (which may be adjusted to 5-20 mg based on efficacy and tolerability) or as a daily dose of 2.5-5 mg. 1

As-Needed Dosing

• The recommended starting dose 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
• The maximum recommended dosing frequency is once per day 1
• Tadalafil improves erectile function for up to 36 hours following dosing, which should be considered when advising patients on optimal use 1
• High-quality evidence shows that tadalafil significantly improves erectile function compared to placebo, with 69% of men reporting successful sexual intercourse attempts versus 33% with placebo 2

Once-Daily Dosing

• The recommended starting dose for once-daily use is 2.5 mg, taken at approximately the same time every day, without regard to timing of sexual activity 1
• The dose may be increased to 5 mg based on individual efficacy and tolerability 1
• Daily dosing eliminates the need to time medication with sexual activity, providing an alternative for couples who prefer spontaneous rather than scheduled sexual activity 2
• Long-term studies have shown that tadalafil 5 mg dosed once daily is well tolerated and effective for up to 2 years 3

Dose Adjustments for Special Populations

Renal Impairment

• For as-needed 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 as-needed use in patients with creatinine clearance <30 mL/min or on hemodialysis: Maximum 5 mg not more than once every 72 hours 1
• For once-daily use in patients with creatinine clearance <30 mL/min or on hemodialysis: Not recommended 1

Hepatic Impairment

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

Efficacy Considerations

• Improvement in erectile function is related to dose for sildenafil and vardenafil but not for tadalafil (20 mg vs. 10 mg vs. 5 mg) 4
• Tadalafil has been shown to be effective across various patient populations, including those with diabetes 5
• On-time (scheduled) dosing of tadalafil twice weekly has shown better efficacy than on-demand dosing in some studies 6

Administration Guidelines

• Tadalafil may be taken without regard to food 1
• Do not split tadalafil tablets; the entire dose should be taken 1
• Sexual stimulation is necessary for tadalafil to be effective, and incorrect use accounts for a large percentage of treatment failures 2

Common Side Effects

• The most common adverse events include dyspepsia, headache, back pain, nasal congestion, and myalgia 2, 7
• Tadalafil has lower rates of flushing compared to other PDE5 inhibitors 2
• Tadalafil is contraindicated in patients taking oral nitrates due to risk of significant hypotension 2

By following these dosing recommendations and considering patient-specific factors, tadalafil can be effectively used to treat erectile dysfunction with minimal side effects.