A Card SR Tablet (Sustained Release) Uses
Isosorbide mononitrate tablets are indicated for-
- The prevention of angina pectoris due to coronary artery disease. The onset of action of oral isosorbide mononitrate is not sufficiently rapid for this product to be useful in aborting an acute anginal episode.
- Long-term treatment of blood-flow disorders of the coronary vessels (coronary heart disease)
- Long-term treatment and prophylaxis of angina pectoris (chest pain due to coronary blood-flow disorders of the coronary vessels).
- Treatment of severe myocardial insufficiency (chronic heart failure)
A Card SR Introduction
Isosorbide-5-mononitrate is an active metabolite of isosorbide dinitrate. It is a vasodilator with effects on both arteries and vein and also coronary vessels. It causes reduction of preload and afterload and redistributes coronary flow to ischemic regions.
Isosorbide mononitrate relaxes vascular smooth muscles by stimulating cyclic-GMP. It decreases left ventricular pressure (preload) and arterial resistance (afterload).
A Card SR Therapeutic Class
Nitrates: Coronary vasodilators
A Card SR Tablet (Sustained Release) Doses
The recommended regimen of Isosorbide Mononitrate tablets is 20 mg (one tablet) twice daily, with the two doses given 7 hours apart. For most patients, this can be accomplished by taking the first dose on awakening and the second dose 7 hours later. Dosage adjustments are not necessary for elderly patients or patients with altered renal or hepatic function.
Multiple studies of organic nitrates have shown that maintenance of continuous 24-hour plasma levels results in refractory tolerance. The dosing regimen for Isosorbide Mononitrate tablets provides a daily nitrate-free interval to avoid the development of this tolerance. Well-controlled studies have shown that tolerance to Isosorbide Mononitrate tablets is avoided when using the twice-daily regimen in which the two doses are given 7 hours apart. This regimen has been shown to have antianginal efficacy beginning 1 hour after the first dose and lasting at least 5 hours after the second dose. The duration (if any) of antianginal activity beyond 12 hours has not been studied; large controlled studies with other nitrates suggest that no dosing regimen should be expected to provide more than about 12 hours of continuous antianginal efficacy per day.
In clinical trials, Isosorbide Mononitrate tablets have been administered in a variety of regimens. Single doses less than 20 mg have not been adequately studied, while single doses greater than 20 mg have demonstrated no greater efficacy than doses of 20 mg.
A Card SR Tablet (Sustained Release) Side Effects
Hypotension, tachycardia, flushing, headache, dizziness, palpitation, syncope, confusion. Nausea, vomiting, abdominal pain. Restlessness, weakness and vertigo. Dry mouth, chest pain, back pain, oedema, fatigue, abdominal pain, constipation, diarrhoea, dyspepsia and flatulence.
A Card SR Precaution
Severe renal or severe hepatic impairment, hypothyroidism, malnutrition, or hypothermia. Caution in patients who are already hypotensive. May aggravate angina caused by hypertrophic cardiomyopathy. Tolerance may develop after long-term treatment. Lactation.
A Card SR Interaction
Hypotensive effects may be increased when used with alcohol or vasodilators. Concurrent use with calcium channel blockers may lead to marked orthostatic hypotension.
A Card SR Uses During Pregnancy
There are no adequate and controlled studies to date with Isosorbide-5-mononitrate in pregnant women, and the drug should be used during pregnancy only when the potential benefit justified possible risks to the fetus. Execration of Isosorbide-5-mononitrate into human milk is unknown, so precaution should be taken when it is administered to a nursing mother.
A Card SR Accute Overdose
Symptoms : Most common symptoms are hypotension, throbbing headache, tachycardia, and flushing. Methemoglobinemia may occur with massive doses.
Treatment: Treatment consists of placing patients in recumbent position and administering fluids; alpha-adrenergic vasopressors may be required. Methemoglobinemia should be treated with methyline blue at a dose of 1-2 mg/kg IV slowly.
A Card SR Contraindication
It is contraindicated in patients who have shown hypersensitivity or idiosyncratic reactions to other nitrates or nitrites.