Zudena 100 mg tablet is used to treat erectile dysfunction (ED). It contains Udenafil, a PDE5 inhibitor, which works by increasing blood flow to the penis during sexual arousal, helping men achieve and sustain an erection. Zudena is typically effective for up to 24-36 hours, providing flexibility for sexual activity. It's essential to consult a healthcare provider before use to ensure it is safe based on individual health conditions and medications.