Viagra generally refers to sildenafil citrate tablets, and there may be side effects associated with the use of this medication, including nasal congestion, headache, and hot flashes, which vary from person to person. Sildenafil citrate tablets are commonly used in the treatment of erectile dysfunction, and should be contraindicated in patients who are using guanylate cyclase agonists (e.g., leucovorin), during regular or intermittent use of nitrate medications, or in patients who are allergic to this product. Side effects that may occur with the use of this medication include nasal congestion, headache, hot flashes, dyspepsia, nausea, myalgia, back pain, vision abnormalities, rash, and dizziness, and the exact occurrence is related to individual variability. Regarding the specific use of Sildenafil Citrate Tablet, it should be used under the guidance of a specialist.