Zhewitra 20 mg, which contains vardenafil, should not be taken in several situations due to the risk of serious health complications. Individuals who are taking nitrate medications for chest pain or heart conditions must avoid Zhewitra 20mg, as the combination can cause a dangerous drop in blood pressure. It should also be avoided by those with severe liver or kidney impairment, low blood pressure, recent history of stroke or heart attack, or certain retinal disorders like retinitis pigmentosa. Men with known hypersensitivity to vardenafil or similar drugs should not take it. Additionally, Zhewitra is not suitable for individuals under 18 or for women. A thorough medical evaluation is recommended before use to avoid harmful interactions and ensure it is safe based on personal health conditions.