The difference between Felodipine Extended-Release Tablets I, also known as Felodipine Extended-Release Tablets (I), and Felodipine Extended-Release Tablets (II) is that the specifications are different and the duration of action of the drug is different. 1. Different specifications: There are two specifications for felodipine extended-release tablets (I), namely 2.5mg and 5mg, while there is only one specification for felodipine extended-release tablets (II), namely 5mg. 2. Different drug action time: the drug action time of felodipine extended-release tablets (II) can last for 24 hours, while the drug action time of felodipine extended-release tablets (I) is relatively shorter. Therefore, felodipine extended-release tablets (II) are also more stable. The indication for felodipine extended-release tablets (I) and (II) is hypertension. Adverse reactions include dizziness, headache, and palpitations (rapid heartbeat, often accompanied by panic). It is contraindicated in patients who are hypersensitive to felodipine or any of the components of the product, acute myocardial infarction, and unstable angina. It should be noted that Felodipine Extended-Release Tablets (I) and (II) are prescription medications and need to be taken properly under medical supervision.