Phosphodiesterase type 5 (PDE5) inhibitors enhance erectile response by increasing cyclic GMP, which relaxes penile smooth muscle and improves blood flow during sexual stimulation.
Daily low-dose tadalafil (typically 2.5 mg to 5 mg) remains active continuously due to its long 17.5-hour half-life, allowing for spontaneous intimacy without planning doses around activity. It is also FDA-approved to alleviate lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH).
As-needed regimens (such as sildenafil 25–100 mg or higher-dose tadalafil 10–20 mg) are taken 30 to 60 minutes prior to intercourse, offering a targeted effect for men who prefer occasional use rather than daily medication.
Risks and limitations
- Both daily and as-needed PDE5 inhibitors are strictly contraindicated with organic nitrates (such as nitroglycerin) due to the risk of severe, life-threatening hypotension.
- Common side effects include headaches, facial flushing, nasal congestion, dyspepsia, and back or muscle aches.