Which antianginal drug is prescribed for prophylaxis and is taken twice daily at 8 am and 4 pm?

• A. Amlodipine
• B. Nitroglycerin
• C. Atenolol
• D. Isosorbide mononitrate

Answer: (D)

Prophylaxis of angina relies on drugs thatProvide a steady antianginal effect while allowing a brief nitrate-free period to keep the body from becoming tolerant to the medication. Isosorbide mononitrate is a long-acting nitrate specifically used for prevention of angina. Its dosing is commonly twice daily, such as in the morning and late afternoon, which aligns with the 8 am and 4 pm schedule. This arrangement maintains protection during waking hours and creates a nitrate-free interval overnight to reduce tolerance. Other agents can prevent angina too, but the twice-daily long-acting nitrate schedule described here is characteristic of isosorbide mononitrate.