Cialis (tadalafil) is a PDE5 inhibitor prescribed for erectile dysfunction (ED) and benign prostatic hyperplasia (BPH). The FDA-approved dosage ranges from 2.5 mg to 20 mg, taken either daily or as needed.
Cialis increases blood flow to the penis by inhibiting phosphodiesterase type 5 (PDE5). This allows nitric oxide to relax smooth muscles in the penis, facilitating erections. For BPH, it relaxes prostate and bladder muscles to improve urine flow.
| Condition | Dosage Range | Frequency |
|---|---|---|
| Erectile Dysfunction | 2.5 mg - 20 mg | Daily or as needed |
| Benign Prostatic Hyperplasia | 5 mg | Daily |
| Combined ED and BPH | 5 mg | Daily |
Doctors may adjust dosages based on patient response, side effects, or other medications. For example, patients taking alpha-blockers or with severe kidney or liver disease often start at lower doses.
One non-obvious fact: Cialis' half-life is 17.5 hours, much longer than rival PDE5 inhibitors like Viagra (half-life: 4 hours). This allows for daily dosing and longer-lasting effects.
Many assume Cialis is only for ED, but it's also FDA-approved for BPH. Others confuse dosage frequency with effectiveness-taking a higher dose daily doesn't necessarily improve results.
I've seen patients mistake Cialis for a daily vitamin, taking it without medical supervision. Always follow a doctor's prescription.