The difference between Avanafil and Sildenafil mainly lies in the drug specifications, contraindications and adverse reactions, etc., the specific use of medication should follow the doctor’s instructions. 1. Specifications: Avanafil has different specifications such as 50mg/tablet, 100mg/tablet, 200mg/tablet, etc., while sildenafil is mostly found in the specifications of 25mg/tablet, 50mg/tablet, 100mg/tablet. 2. Contraindications: Avanafil is contraindicated in women, people under 18 years of age, people who are allergic to it, or people who are taking nitrate drugs such as nitroglycerin; Sildenafil, in addition to the above contraindications, is also prohibited from being used in combination with guanylate cyclase agonists such as levocetirizine. 3. Adverse reactions: the common adverse reactions of avanafil include headache, flushing, nasopharyngitis, muscle pain, etc.; the common adverse reactions of sildenafil include dizziness, visual anomalies, hot flashes (a burst of fever), dyspepsia and so on. In addition, there are also major differences in the dosage of the two drugs. Those who have the need to use such drugs must choose and standardize the use of drugs according to the actual situation under the guidance of a doctor, and must not use them blindly on their own to avoid adverse consequences.