When to use Imdur (Isosorbide Mononitrate)?

From the Guidelines

Imdur (isosorbide mononitrate) should be used to prevent and treat angina in patients with coronary artery disease who experience recurring angina episodes despite using short-acting nitrates like nitroglycerin, as recommended by the American College of Physicians 1.

Key Considerations

• Imdur is an extended-release medication taken once or twice daily, usually starting at 30-60 mg doses, to relax blood vessels, improve blood flow to the heart muscle, and reduce the workload on the heart.
• The medication should be taken exactly as prescribed, usually in the morning on an empty stomach, with the second dose (if needed) taken 7 hours after the first to prevent nitrate tolerance, as outlined in the ACC/AHA 2007 guidelines 1.
• Patients should not stop taking Imdur suddenly as this may worsen angina symptoms.
• Common side effects include headache, dizziness, and lightheadedness, especially when starting treatment.
• Imdur should not be taken with erectile dysfunction medications like Viagra as this combination can cause dangerous drops in blood pressure, as warned in the ACC/AHA 2007 guidelines 1.

Important Interactions and Contraindications

• Imdur is contraindicated after the use of sildenafil within the previous 24 h or tadalafil within 48 h, or with hypotension, as stated in the ACC/AHA 2007 guidelines 1.
• The suitable delay before nitrate administration after the use of vardenafil has not been determined, although blood pressure had generally returned to baseline by 24 h, as noted in the ACC/AHA 2007 guidelines 1.

Dosage and Administration

• The recommended dosage of Imdur is 30-60 mg once or twice daily, with the second dose (if needed) taken 7 hours after the first, as recommended by the American College of Physicians 1.
• The medication should be taken on an empty stomach to improve absorption and reduce the risk of side effects.

From the FDA Drug Label

Isosorbide mononitrate extended-release 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.

Use of Imdur (Isosorbide Mononitrate):

• Imdur is used for the prevention of angina pectoris due to coronary artery disease.
• It is not recommended for aborting an acute anginal episode due to its slow onset of action.
• Patients should take the dose on arising to maintain the antianginal efficacy of isosorbide mononitrate extended-release tablets 2.

From the Research

Usage of Imdur

• Imdur is used for the treatment of chronic stable angina pectoris 3, 4, 5, 6.
• It is a sustained-release isosorbide 5-mononitrate preparation that provides effective antianginal prophylaxis for up to 12 hours 3.
• The most widely studied dosage is 60 mg once daily, which has significant antianginal and anti-ischaemic effects compared with placebo after 2 weeks' treatment 3.

Efficacy and Tolerance

• Studies have shown that Imdur 60 mg once daily is more effective than isosorbide dinitrate 30 mg 4 times daily and similar to or better than isosorbide dinitrate 20 mg 3 times daily 3.
• There is no evidence of classical tolerance to Imdur 30 to 240 mg/day in a large well-designed study 3.
• Abrupt discontinuation during long-term Imdur treatment may exacerbate anginal symptoms 3.

Combination Therapy

• Imdur in combination with a beta-blocker significantly increases the anti-anginal effect compared with beta-blockade alone 5.
• The addition of Imdur once daily to beta-blockade significantly decreased the attack rate and nitroglycerin consumption 5.

Administration and Side Effects

• Imdur is generally well tolerated, with the most frequently reported adverse event being headache, which is usually mild to moderate and improves with long-term therapy 3, 4, 6.
• Patient compliance is better with once-daily administration of Imdur than with twice-daily administration of conventional isosorbide 5-mononitrate 3.