What is the proper administration of Tadalafil (tadalafil) tablets?

How to Administer Tadalafil Tablets

Tadalafil tablets should be swallowed whole without splitting, and can be taken without regard to food, with dosing strategy determined by whether treatment is for erectile dysfunction (as-needed vs. daily), benign prostatic hyperplasia, or both conditions. 1

Administration Fundamentals

• Do not split tadalafil tablets – the entire dose must be taken as a whole tablet 1
• Food does not affect absorption – tadalafil may be taken without regard to meals 1
• Timing varies by indication – as-needed dosing requires planning ahead, while daily dosing does not require temporal coordination with sexual activity 1

Dosing Strategies for Erectile Dysfunction

As-Needed Dosing (On-Demand)

• Start with 10 mg taken at least 30 minutes before anticipated sexual activity 1
• Titrate based on response: increase to 20 mg or decrease to 5 mg depending on efficacy and tolerability 1
• Maximum frequency is once per day in most patients 1
• Therapeutic window extends up to 36 hours after dosing, which should be considered when counseling patients on optimal use 1

Once-Daily Dosing

• Start with 2.5 mg taken at approximately the same time every day 1
• May increase to 5 mg daily based on individual efficacy and tolerability 1
• No need to time dosing with sexual activity – this approach allows for spontaneous rather than scheduled intimacy 2, 1
• Sexual stimulation is still required for the medication to be effective 3

Dosing for Benign Prostatic Hyperplasia

• Use 5 mg once daily taken at approximately the same time every day 1
• When combining with finasteride: continue 5 mg daily tadalafil for up to 26 weeks 1

Dosing for Combined ED and BPH

• Use 5 mg once daily taken at approximately the same time every day, without regard to timing of sexual activity 1

Critical Safety Considerations

Absolute Contraindications

• Nitrates are absolutely contraindicated with tadalafil due to severe hypotension risk 2, 4
• Avoid nitrates for at least 48 hours after tadalafil use (compared to 24 hours for sildenafil/vardenafil) 2, 3

Dose Adjustments for Renal Impairment

For As-Needed Dosing:

• CrCl 30-50 mL/min: Start with 5 mg maximum once daily; maximum dose 10 mg once every 48 hours 1
• CrCl <30 mL/min or hemodialysis: Maximum 5 mg once every 72 hours 1

For Daily Dosing (ED):

• CrCl <30 mL/min or hemodialysis: Daily dosing is not recommended 1

For Daily Dosing (BPH or ED/BPH):

• CrCl 30-50 mL/min: Start with 2.5 mg daily; may increase to 5 mg based on response 1
• CrCl <30 mL/min or hemodialysis: Daily dosing is not recommended 1

Dose Adjustments for Hepatic Impairment

For As-Needed Dosing:

• Mild or moderate impairment (Child-Pugh A or B): Do not exceed 10 mg once daily 1
• Severe impairment: Not recommended due to insufficient data 1

For Daily Dosing:

• Mild or moderate impairment: Use with caution; not extensively evaluated 1
• Severe impairment: Not recommended 1

Drug Interactions Requiring Dose Adjustment

With Potent CYP3A4 Inhibitors (ritonavir, ketoconazole, itraconazole):

• As-needed dosing: Limit to 10 mg maximum once every 72 hours 1
• Daily dosing: Maximum 2.5 mg daily 1

Alcohol Interaction

• Substantial alcohol consumption (≥5 units) combined with tadalafil can increase orthostatic symptoms including increased heart rate, decreased standing blood pressure, dizziness, and headache 1

Patient Counseling Points

Efficacy Expectations

• Multiple trials may be required to establish efficacy – patients should not abandon treatment after a single unsuccessful attempt 3
• Sexual stimulation is necessary for tadalafil to work 3
• For as-needed dosing: Improved ability to have sexual intercourse extends up to 36 hours in most patients 1
• For daily dosing: Erectile function improves over the course of continuous therapy 1

Common Adverse Effects

• Most frequent side effects include headache, dyspepsia, back pain, myalgia, nasal congestion, and flushing 5, 3
• Most adverse events are transient and mild to moderate in severity 3
• Dose titration may be necessary to find the optimal balance between efficacy and side effects 3

Emergency Situations

• Seek emergency care for erections lasting >4 hours (whether painful or not) to prevent irreversible erectile tissue damage 1
• Stop tadalafil and seek prompt medical attention for sudden vision loss in one or both eyes, which may indicate NAION 1
• Stop tadalafil and seek prompt medical attention for sudden hearing loss, which may be accompanied by tinnitus and dizziness 1

Special Populations

Diabetic Patients

• Men with diabetes respond less robustly to PDE5 inhibitors compared to the general ED population, but tadalafil can still significantly improve erectile function 3
• Efficacy is independent of baseline HbA1c levels 3

Testosterone Deficiency

• Tadalafil combined with testosterone therapy is more effective than tadalafil alone in men with both ED and testosterone deficiency 3

Cardiovascular Risk Assessment

• Patients unable to perform moderate exercise (walking 1 mile in 20 minutes or climbing 2 flights of stairs in 20 seconds) should be referred to cardiology before treatment 4

Common Pitfalls to Avoid

• Do not assume improvement is dose-related – unlike sildenafil and vardenafil, tadalafil efficacy is NOT consistently dose-dependent 3
• Do not use tadalafil with other PDE5 inhibitors or erectile dysfunction therapies – safety and efficacy of combinations have not been studied 1
• Do not forget to assess for other urological conditions before initiating treatment for BPH, as prostate cancer and BPH may coexist 1
• Tadalafil offers no protection against sexually transmitted diseases – counsel patients about protective measures including HIV prevention 1