home > drugs a-z list > ismo (isosorbide mononitrate) drug center > ismo (isosorbide mononitrate) drug - medication guide and patient information

Patients should be told that the antianginal efficacy of Ismo (isosorbide mononitrate) tablets can be maintained by carefully following the prescribed schedule of dosing (two doses taken 7 hours apart). For most patients, this can be accomplished by taking the first dose on awakening and the second dose 7 hours later. As with other nitrates, daily headaches sometimes accompany treatment with isosorbide mononitrate. In patients who get these headaches, the headaches are a marker of the activity of the drug. Patients should resist the temptation to avoid headaches by altering the schedule of their treatment with isosorbide mononitrate, since loss of headache may be associated with simultaneous loss of antianginal efficacy. Aspirin and/or acetaminophen, on the other hand, often successfully relieve isosorbide mononitrate-induced headaches with no deleterious effect on isosorbide mononitrate's antianginal efficacy. Treatment with isosorbide mononitrate may be associated with lightheadedness on standing, especially just after rising from a recumbent or seated position. This effect may be more frequent in patients who have also consumed alcohol.

Last reviewed on RxList: 4/13/2009
This monograph has been modified to include the generic and brand name in many instances.