Which duration is commonly recommended for the nitrate-free interval with long-acting nitrates?

• A. 4 hours
• B. 12 hours
• C. 8 hours
• D. 24 hours

Answer: (C)

Nitrate-free intervals exist to prevent tolerance to long-acting nitrates while still providing protection when it’s most needed. Eight hours is commonly recommended because it gives a meaningful off-period that helps restore the medication’s effectiveness, without leaving too long a gap during waking hours when angina risk is present. Shorter off-times, like four hours, may not prevent tolerance effectively, while longer off-times, such as twelve or twenty-four hours, can leave patients without adequate protection for longer periods. So, eight hours strikes a practical balance used in many regimens.