Comparable Medications to Cialis (Tadalafil)
Sildenafil (Viagra) and vardenafil (Levitra) are the most comparable medications to tadalafil (Cialis), with all three being effective PDE5 inhibitors for erectile dysfunction treatment with similar efficacy rates of approximately 69% for successful sexual intercourse. 1
PDE5 Inhibitors Overview
All FDA-approved PDE5 inhibitors have demonstrated high efficacy in treating erectile dysfunction:
- Tadalafil (Cialis): 69% success rate for intercourse attempts vs. 33% for placebo 1
- Sildenafil (Viagra): 69% success rate for intercourse attempts vs. 35.5% for placebo 1
- Vardenafil (Levitra): 68% success rate for intercourse attempts vs. 35% for placebo 1
- Avanafil (Stendra) and Udenafil (Zydena) are newer PDE5 inhibitors also available in some markets 2
Key Differences Between PDE5 Inhibitors
Duration of Action
- Tadalafil (Cialis): Longest half-life at 17.5 hours; can last up to 36 hours 3
- Sildenafil (Viagra): Half-life of approximately 4 hours 3
- Vardenafil (Levitra): Half-life of approximately 4 hours 3
Onset of Action
- Sildenafil: 35% of patients achieve successful erection within 14 minutes 3
- Vardenafil: 21% of patients achieve successful erection within 10 minutes 3
- Tadalafil: 16% of patients achieve successful erection within 16 minutes 3
Food Interactions
- Tadalafil: Not affected by food intake 3
- Sildenafil and Vardenafil: Absorption and efficacy reduced by fatty meals 3
Dosing Options
- Tadalafil: Available as 5-20mg as needed, or 2.5-5mg daily dosing 4
- Sildenafil: 25-100mg as needed 4
- Vardenafil: Typically 10-20mg as needed
Efficacy and Side Effect Trade-offs
- Sildenafil 50mg: Highest efficacy but also highest rate of overall adverse events 2
- Tadalafil 10mg: Intermediate efficacy with lowest overall rate of adverse events 2
- Vardenafil 10mg and Avanafil 100mg: Similar adverse event profiles to sildenafil but lower global efficacy 2
Common Side Effects
All PDE5 inhibitors share similar side effect profiles including:
- Headache
- Flushing
- Dyspepsia (indigestion)
- Nasal congestion
- Back pain and myalgia (more common with tadalafil)
- Visual disturbances (more common with sildenafil) 4
Important Considerations and Contraindications
Nitrate medications: All PDE5 inhibitors are contraindicated with nitrates
- Wait at least 24 hours after sildenafil/vardenafil
- Wait at least 48 hours after tadalafil 4
Alpha-blockers: Use with caution due to potential hypotension 4
Cardiovascular risk: Assess cardiovascular status before prescribing any PDE5 inhibitor 4
Patient Preference Considerations
In comparison studies, tadalafil is often preferred over sildenafil by men with ED, likely due to its longer duration of action and lack of food interactions 5. This allows for more spontaneity in sexual activity without planning around medication timing.
Optimizing Treatment Selection
- For patients prioritizing high efficacy: Sildenafil 50mg appears to be the treatment of choice 2
- For patients prioritizing tolerability: Tadalafil 10mg offers the best balance of efficacy and side effects 2
- For patients needing flexibility with timing of sexual activity: Tadalafil's longer duration of action may be preferable 3, 5
Remember that proper medication use is crucial for success with any PDE5 inhibitor, including adequate sexual stimulation, correct timing, and appropriate dosing 4.