Zudena 100 mg contains udenafil 100 mg, a PDE5 inhibitor prescribed for erectile dysfunction (ED) in adult men. For prescribing, available product information states that 100 mg is the usual starting dose, taken orally approximately 30 minutes to 12 hours before ***** activity, with a maximum frequency of once daily. It may be taken with or without food. Because Zudena is a prescription medicine, a doctor should determine whether 100 mg is appropriate based on medical history, other medicines, and cardiovascular risk. The manufacturer specifically advises not exceeding one tablet daily without medical consultation. Important: Udenafil should not be used with nitrate medicines, because the combination can cause a potentially dangerous drop in blood pressure.