Nifedipine extended-release tablets are generally available two hours after eating, the effect of the drug can last for about 12 hours, but there are still individual differences between different people. Nifedipine extended-release tablets belong to the slow-release preparations, the role of oral medication is relatively slow, two hours after taking the drug can reach the peak of efficacy, and begin to play the role of antihypertensive. The efficacy of nifedipine extended-release tablets can be maintained for about 12 hours, and patients with high blood pressure need to take the tablets twice a day to maintain the effective concentration needed. The adverse reactions of nifedipine extended-release tablets include flushing, tachycardia, nausea, abdominal distension, limb pain, etc. It is forbidden to use it for women who are allergic to the components of the drug, patients taking rifampicin, cardiogenic shock, acute myocardial infarction in the acute stage, and women in pregnancy. Nifedipine extended-release tablets should be used under the guidance of a physician, avoid purchasing drugs on your own, and pay attention to the adverse effects of drugs when taking medication.