How to Take PRN Cialis (Tadalafil)
For PRN (as needed) use, take Cialis 30 minutes to 2 hours before anticipated sexual activity, with or without food, at a starting dose of 10 mg that can be adjusted between 5-20 mg based on efficacy and tolerability. 1, 2
Dosing Guidelines
- The recommended starting dose for PRN use is 10 mg, which can be increased to 20 mg or decreased to 5 mg based on individual response and side effects 1
- Take the medication prior to anticipated sexual activity - Cialis can be effective from 30 minutes after administration and remains effective for up to 36 hours 2, 1
- Do not take Cialis more than once per day 1
- Cialis can be taken with or without food - meals do not significantly affect absorption 1
- Do not split tablets; the entire dose should be taken 1
- Sexual stimulation is necessary for the medication to be effective - Cialis will not work without sexual arousal 2, 1
Special Populations and Dose Adjustments
- For patients with mild to moderate renal impairment (creatinine clearance 30-50 mL/min): Starting dose of 5 mg not more than once per day, with maximum dose of 10 mg not more than once every 48 hours 1
- For severe renal impairment (creatinine clearance less than 30 mL/min): Maximum dose is 5 mg not more than once every 72 hours 1
- For mild to moderate hepatic impairment: Dose should not exceed 10 mg once per day 1
- For patients taking medications that inhibit CYP3A4 (like ketoconazole, ritonavir): Lower starting doses may be needed 3, 1
- For patients taking alpha-blockers: Start with the lowest dose of Cialis to minimize risk of hypotension 3, 1
Efficacy Considerations
- Improvement in erectile function with tadalafil is not strictly dose-dependent between 5-20 mg, unlike other PDE5 inhibitors 2
- If PRN Cialis is not effective after at least 5 separate attempts at the maximum dose, consider trying daily Cialis or consulting your healthcare provider 4, 5
- Some studies suggest that once-daily administration may provide better erectile function improvement than PRN use in some patients 6
Important Safety Information
- Do not take Cialis if you are taking nitrate medications (e.g., nitroglycerin) as this combination can cause severe hypotension 1
- Avoid excessive alcohol consumption when taking Cialis, as it may increase the risk of dizziness, headache, and low blood pressure 1
- Seek immediate medical attention for erections lasting more than 4 hours (priapism), as this can cause permanent damage to erectile tissue 1
- Common side effects include headache, indigestion, back pain, muscle aches, flushing, and nasal congestion 1
- If you experience sudden vision loss or hearing loss while taking Cialis, seek immediate medical attention 1
Common Pitfalls to Avoid
- Not allowing enough time before sexual activity - while Cialis can work within 30 minutes, optimal effects may take 1-2 hours 2, 7
- Taking Cialis more frequently than recommended (more than once daily) 1
- Expecting the medication to work without sexual stimulation 2, 1
- Not trying the medication multiple times before concluding it's ineffective - an adequate trial requires at least 5 attempts 4
- Failing to disclose all medications to your healthcare provider, which could lead to dangerous drug interactions 1