For which condition is Nifedipine indicated?

Nifedipine is a calcium channel blocker that is specifically indicated for the treatment of hypertension. It works by relaxing the smooth muscles of blood vessels, leading to vasodilation and a subsequent decrease in blood pressure. This makes it particularly useful in managing high blood pressure in patients. Additionally, nifedipine can also be used for certain other cardiovascular conditions, such as angina, due to its ability to improve blood flow to the heart.

When considering other conditions listed, heart failure, chronic pain, and allergic reactions are not treated with nifedipine. Heart failure requires medications that help manage fluid balance and improve heart function rather than just lowering blood pressure. Chronic pain typically involves analgesics or anti-inflammatory medications for management, and allergic reactions are treated with antihistamines or corticosteroids. Thus, the indication of nifedipine for hypertension is clear and appropriate for its pharmacological action.