Tadalafil Dosing Guidelines
The recommended dose range for tadalafil varies based on the indication, with 2.5-20 mg for erectile dysfunction (as needed or once daily), 5 mg for benign prostatic hyperplasia, and 0.5-1 mg/kg (maximum 40 mg) for pediatric pulmonary hypertension. 1, 2
Erectile Dysfunction (ED) Dosing
As-Needed Dosing
- Starting dose: 10 mg taken prior to anticipated sexual activity
- Dose adjustment: May be increased to 20 mg or decreased to 5 mg based on efficacy and tolerability
- Maximum frequency: Once per day in most patients
- Timing: Can be effective up to 36 hours following dosing 1
Once-Daily Dosing
- Starting dose: 2.5 mg taken at approximately the same time every day
- Dose adjustment: May be increased to 5 mg based on individual response
- Timing: Without regard to timing of sexual activity 1
- Efficacy: High-quality evidence shows once-daily tadalafil 5 mg significantly improves erectile function compared to placebo 3, 4
Benign Prostatic Hyperplasia (BPH) Dosing
- Recommended dose: 5 mg once daily, taken at approximately the same time every day 1
- Combination therapy: When used with finasteride, 5 mg once daily for up to 26 weeks 1
- Efficacy: Tadalafil 5 mg significantly improves both ED and BPH-related symptoms through 12 weeks 5, 2
Pulmonary Hypertension Dosing
- Pediatric starting dose: 0.5-1 mg/kg/day
- Maximum dose: 40 mg daily
- Age restriction: Evaluated only in children >3 years of age 2
Special Population Considerations
Renal Impairment
- Creatinine clearance 30-50 mL/min:
- As-needed: Start with 5 mg, maximum 10 mg every 48 hours
- Once-daily for BPH/ED: Start with 2.5 mg, may increase to 5 mg
- Creatinine clearance <30 mL/min:
- As-needed: Maximum 5 mg every 72 hours
- Once-daily: Not recommended 1
Hepatic Impairment
- Mild to moderate impairment (Child-Pugh A or B):
- As-needed: Maximum 10 mg once per day
- Once-daily: Use with caution
- Severe impairment (Child-Pugh C): Not recommended 1
Drug Interactions
- Potent CYP3A4 inhibitors (ritonavir, ketoconazole, itraconazole):
- As-needed: Limit to 10 mg no more than once every 72 hours
- Once-daily: Maximum 2.5 mg 1
Administration Considerations
- Can be taken without regard to food
- Tablets should not be split; entire dose should be taken
- Avoid substantial alcohol consumption when taking tadalafil 1
Efficacy Considerations
- For ED, low-dose (5 mg) daily tadalafil may be sufficient for patients with PSV >15 cm/s, while higher doses (10 mg) may be needed for those with PSV <15 cm/s 6
- Long-term studies show sustained efficacy and safety with tadalafil 5 mg once daily for up to 2 years 4
Common Side Effects
Always consider the specific indication, renal and hepatic function, and potential drug interactions when selecting the appropriate tadalafil dose for your patient.