Viagra is the trade name, generic name is sildenafil citrate tablets, contraindications for taking this product for the first time include prohibited for those who are allergic to its ingredients, prohibited to be combined with levocetirizine and so on. Sildenafil Citrate Tablet is a western medicine used to treat erectile dysfunction. Contraindications for taking sildenafil citrate tablets for the first time are prohibited for those who are allergic to its ingredients; combining with guanylate cyclase agonists such as leucovorin is prohibited to avoid causing hypotension. In addition, this drug is also contraindicated in women, children, and people who should not have sex in recent cardiovascular conditions. Common adverse reactions to sildenafil citrate tablets include malaise, anaphylactic reactions, palpitations, dry mouth, chills, accidental falls, and abdominal pain. Note that if there is any loss or decrease of hearing during the use of the drug, it should be discontinued and medical attention should be sought as soon as possible; if the erection persists for more than 4 hours after the use of the drug, it should be sought immediately. Avoid taking this product while taking nitrates, either intermittently or regularly. If you need to use this product, it should be applied under the guidance of a physician, and should not be taken on its own to avoid adverse consequences.