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    Isosorbide Mononitrate

    Topic Contents

    Isosorbide Mononitrate

    Drug Information

    Isosorbide mononitrate (ISMN) is a member of the nitrate family of drugs used to prevent angina (chest pain). It is available in immediate-release and extended-release products.

    Common brand names:

    Imdur, IMSO, Monoket

    Summary of Interactions with Vitamins, Herbs, & Foods

    Types of interactions: Beneficial Adverse Check

    Replenish Depleted Nutrients

    • none

    Reduce Side Effects

    • none

    Support Medicine

    • N-Acetyl Cysteine

      In a double-blind trial, sustained-release ISMN plus oral NAC (2,400 mg twice per day) for two days led to significantly longer exercise time than ISMN plus placebo.1 This outcome suggests that NAC may have increased the efficacy of ISMN. There were no differences in side effects between the two groups.

    Reduces Effectiveness

    • none

    Potential Negative Interaction

    • none

    Explanation Required 

    • Vitamin C

      Some persons taking nitroglycerin or isosorbide mononitrate may find that it loses efficacy over time. This is because the body adapts to the drug, a process known as developing tolerance. One study found that taking 2 grams three times daily of vitamin C can decrease this effect when nitroglycerin patches are simultaneously used.2 Similar benefits have been confirmed in another study.3 However, it should be noted that it is also possible to avoid tolerance to these drugs by simply changing the dosing schedule. People taking ISMN or nitroglycerin should talk with their pharmacists about avoiding drug tolerance.

    The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers' package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.


    1. Svendsen JH, Klarlund K, Aldershvile J, Waldorff S. N-acetylcysteine modifies the acute effects of isosorbide-5-mononitrate in angina pectoris patients evaluated by exercise testing. J Cardiovasc Pharmacol 1989;13:320-3.

    2. Watanabe H, Kakihana M, Ohtsuka S, Sugishita Y. Randomized, double-blind, placebo-controlled study of the preventive effect of supplemental oral vitamin C on attenuation of development of nitrate tolerance. J Am Coll Cardiol 1998;31:1323-9.

    3. Bassenge E, Fink N, Skatchkov M, Fink B. Dietary supplement with vitamin C prevents nitrate tolerance. J Clin Invest 1998;102:67-71.

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