Detailed Drug Information:

DRUG CLASS AND MECHANISM: The pain of coronary heart disease(angina) usually occurs when the heart requires more blood and oxygen thanits blood vessels supplying the heart can deliver. The demand for oxygencan be reduced and pain prevented in one of two ways. First, by dilatingthe veins and allowing more blood to "pool." This reduces theamount of blood returning to the heart and hence the heart's work andneed for oxygen. Second, by dilating the arteries of the body and reducingthe pressure within the arteries. This reduces the pressure that the hearthas to pump against and hence the Heart's work and need for oxygen.Isosorbide mononitrate reduces angina by dilating both the veins and thearteries.

Isosorbide mononitrate also increases supply of oxygen to the heart bydilating the arteries which supply the heart itself. Isosorbidemononitrate is in the class of drugs called anti-anginal medications.Isosorbide mononitrate is the chief metabolite of isosorbide dinitrate,and most of the activity of isosorbide dinitrate is due to its metabolite,isosorbide mononitrate.

PREPARATIONS: Uncoated tablets (10mg, 20mg); sustained-actiontablets (60mg, 120mg).

STORAGE: Isosorbide mononitrate should be stored at roomtemperature - 15-30°C (59-86°F) - in a tight moisture-proofcontainer.

PRESCRIBED FOR: Isosorbide mononitrate is used for theprevention of angina. It can be used to decrease the frequency andseverity of anginal (chest pain) episodes and to reduce the need forsublingual (taken under the tongue) nitroglycerin.

DOSING: ISMO is taken twice daily, with the two doses taken 7hours apart. Imdur generally is taken once daily. Doses are not changed inpatients with liver or kidney diseases.

DRUG INTERACTIONS: Since isosorbide mononitrate can causehypotension (low blood pressure), other medications which can reduce bloodpressure may produce additive effects causing serious drops in bloodpressure. Such drugs might include those used to treat high bloodpressure, some antidepressants; some anti-psychotics, quinidine,procainamide, benzodiazepines such as diazepam (Valium) or opiates (e.g.morphine).

Since ethanol also may intensify the blood pressure lowering effect ofisosorbide mononitrate, patients receiving isosorbide mononitrate shouldbe advised to use ethanol with caution.

PREGNANCY: Since most persons who use isosorbide mononitrate areover 50 years of age, experience with use during pregnancy is limited.Isosorbide mononitrate can be used during pregnancy if the physicianbelieves the benefits justify the potential and unknown risks to thefetus.

NURSING MOTHERS: It is not known if isosorbide mononitrate is secreted in breast milk.

SIDE EFFECTS: Headaches are the most common side effect andusually are dose-related (increase with higher dosages). Headaches mayoccur in about 1 in 10 (10%) to 1 in 5 (20%) of all persons takingisosorbide mononitrate. Far less frequently, dizziness, nausea, vomiting,and palpitations occur.