Imdur

The pain of coronary heart disease (angina) usually occurs when the heart requires more blood and oxygen than its blood vessels supplying the heart can deliver. The demand for oxygen can be reduced and pain prevented in one of two ways. First, by dilating the veins and allowing more blood to "pool." This reduces the amount of blood returning to the heart and hence the heart's work and need for oxygen. Second, by dilating the arteries of the body and reducing the pressure within the arteries. This reduces the pressure that the heart has to pump against and hence the Heart's work and need for oxygen. Isosorbide mononitrate reduces angina by dilating both the veins and the arteries.

Isosorbide mononitrate also increases supply of oxygen to the heart by dilating the arteries which supply the heart itself. Isosorbide mononitrate 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.

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

Headaches are the most common side effect and usually are dose-related (increase with higher dosages). Headaches may occur in about 1 in 10 (10%) to 1 in 5 (20%) of all persons taking isosorbide mononitrate. Far less frequently, dizziness, nausea, vomiting, and palpitations occur.

Since isosorbide mononitrate can cause hypotension (low blood pressure), other medications which can reduce blood pressure may produce additive effects causing serious drops in blood pressure. Such drugs might include those used to treat high blood pressure, 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 of isosorbide mononitrate, patients receiving isosorbide mononitrate should be advised to use ethanol with caution.

Isosorbide mononitrate is used for the prevention of angina. It can be used to decrease the frequency and severity of anginal (chest pain) episodes and to reduce the need for sublingual (taken under the tongue) nitroglycerin.

Isosorbide mononitrate should be stored at room temperature - 15-30°C (59-86°F) - in a tight moisture- proof container.