Isosorbide mononitrate



    • Prophylactic prevention of angina pectoris due to coronary artery disease

    • Treatment of acute and chronic angina pectoris, hypertension, and myocardial infarction


    • Oral

    • 100% absorbed


    • 20 - 120 mg


    • VOD 0.6 to 0.7 L/kg

    • 5 % protein bound


    • Similar to other nitrites and organic nitrates, Isosorbide Mononitrate is converted to nitric oxide (NO)

      • Active intermediate compound which activates the enzyme guanylate cyclase (Atrial natriuretic peptide receptor A).

    • This stimulates the synthesis of cyclic guanosine 3',5'-monophosphate (cGMP)

      • This activates a series of protein kinase-dependent phosphorylations in the smooth muscle cells

      • Eventually results in the dephosphorylation of the myosin light chain of the smooth muscle fiber.

    • The subsequent release of calcium ions results in the relaxation of the smooth muscle cells and vasodilation.

    • By dilating the vessels, it lowers the blood pressure and reduces the left ventricular preload and afterload, therefore, leads to a reduction of myocardial oxygen requirement


    • Isosorbide mononitrate is primarily metabolized by the liver, but unlike oral isosorbide dinitrate, it is not subject to first-pass metabolism.

    • Isosorbide mononitrate is cleared by denitration to isosorbide and glucuronidation as the mononitrate

      • 96% of the administered dose excreted in the urine within 5 days and only about 1% eliminated in the feces

    • At least six different compounds have been detected in urine, with about 2% of the dose excreted as the unchanged drug and at least five metabolites.

    • Half-life 5 hours

Side effects

    • Very common

      • Headache predominates (up to 30%) necessitating withdrawal of 2 to 3 % of patients, but the incidence reduces rapidly as treatment continues .

    • Common

      • Tiredness, sleep disturbances (6%) and gastrointestinal disturbances (6%) have been reported during clinical trials with isosorbide mononitrate modified release tablets, but at a frequency no greater than for placebo.

      • Hypotension (4 to 5%), poor appetite (2.5%), nausea (1%).

    • Hypotension (4%) with symptoms such as dizziness and nausea (1%) have been reported.

      • These symptoms generally disappear during long-term treatment.

    • Other reactions that have been reported with isosorbide mononitrate modified release tablets include tachycardia, vomiting, diarrhoea, vertigo and heartburn