Isosorbide Dinitrate
Indications
Isosorbide Dinitrate is used for:
Angina, Percutaneous transluminal coronary angioplasty
Adult Dose
Angina Pectoris
Immediate release: 5-20 mg PO q8-12hr initially; maintenance: 10-40 mg PO q8-12hr
Child Dose
Renal Dose
Administration
Should be taken on an empty stomach. Take on an empty stomach ½ hr before meals.
Contra Indications
Severe hypotension or anaemia, hypovolaemia, heart failure due to obstruction, or raised intracranial pressure due to head trauma or cerebral haemorrhage.
Precautions
Raised intracranial pressure, hypotension, hypovolaemia. Mitral valve prolapse, arterial hypoxaemia, glaucoma, elderly, hypothyroidism, malnutrition, pregnancy, lactation
Lactation: Unknown whether drug is distributed into breast milk
Pregnancy-Lactation
Pregnancy category: C
Lactation: Unknown whether drug is distributed into breast milk
Interactions
Increased hypotensive effects with alcohol or vasodilators. Marked orthostatic hypotension may occur when used with calcium channel blockers. Vasodilatory effect may be reduced with dihydroergotamine. Ergotamine effects may be enhanced. Reduced effectiveness of sublingual form with disopyramide.
Potentially Fatal: Significant hypotension may occur with phosphodiesterase-5 inhibitors.
Adverse Effects
Side effects of Isosorbide Dinitrate :
Cardiovascular: Rebound hypertension (uncommon), syncope, unstable angina flushing, hypotension/orthostatic hypotension, lightheadedness, palpitations, tachyarrhythmia
Central nervous system (CNS): Dizziness, headache, restlessness, weakness
Gastrointestinal (GI): Nausea
Hematologic: Methemoglobinemia (infrequent)
Potentially Fatal: Severe hypotension, circulatory collapse.
Mechanism of Action
Isosorbide dinitrate relaxes vascular smooth muscles by stimulating cyclic-GMP. It decreases left ventricular pressure (preload) and arterial resistance (afterload).