Isosorbide Mononitrate

A to Z Drug Facts

Isosorbide Mononitrate

	Action
	Indications
	Contraindications
	Route/Dosage
	Interactions
	Lab Test Interferences
	Adverse Reactions
	Precautions
Patient Care Considerations
	Administration/Storage
	Assessment/Interventions
	Patient/Family Education

(EYE-sos-ORE-bide MAH-no-NYE-trate)

ISMO, Imdur, Monoket, Isotrate ER

Class: Antianginal

Action Relaxation of smooth muscle of venous and arterial vasculature.

Indications Prevention of angina pectoris.

Contraindications Hypersensitivity to nitrates; severe anemia; closed-angle glaucoma; orthostatic hypotension; head trauma or cerebral hemorrhage.

Route/Dosage

ADULTS: PO 20 mg bid, given 7 hr apart. Extended release tablets are given as 30 (½ of 60 mg tablet) or 60 mg once daily. After several days dosage may be increased to 120 mg (given as two 60 mg tablets) once daily. Rarely, 240 mg may be required.

Interactions

Alcohol: Severe hypotension and cardiovascular collapse may occur. Aspirin: Increased nitrate concentration and actions. Calcium channel blockers: Symptomatic orthostatic hypotension. Dihydroergotamine: Increased systolic BP and decreased antianginal effects may develop.

Lab Test Interferences May cause false report of reduced serum cholesterol with Zlatkis-Zak color reaction.

Adverse Reactions

CV: Tachycardia; palpitations; hypotension; syncope; arrhythmias. CNS: Headache; apprehension; weakness; vertigo; dizziness; agitation; insomnia. DERM: Cutaneous vasodilation with flushing. EENT: Blurred vision. GI: Nausea; vomiting; diarrhea; dyspepsia. GU: Dysuria; urinary frequency; impotence. HEMA: Methemoglobinemia; hemolytic anemia. OTHER: Arthralgia; perspiration; pallor; cold sweat; edema.

Precautions

Pregnancy: Category C. Lactation: Undetermined. Special risk patients: Use with caution in patients with acute MI, CHF, glaucoma or angina caused by hypertrophic cardiomyopathy. Acute angina: Not indicated for treatment of acute anginal episodes. Orthostatic hypotension: May occur even with small doses; alcohol accentuates this reaction. Tolerance: Tolerance to vascular and antianginal effects may develop.

PATIENT CARE CONSIDERATIONS

Administration/Storage

Administer first dose on awakening and second dose 7 hr later.
Give on empty stomach with full glass of water.
Tablets should not be crushed or chewed and should be swallowed together.
Store at cool temperature in tightly closed container.

Assessment/Interventions

Obtain patient history, including drug history and any known allergies.
Monitor for headache, hypotension, and tachycardia.

OVERDOSAGE: SIGNS & SYMPTOMS
	Hypotension, tachycardia, flushing, diaphoresis, headache, vertigo, palpitations, visual disturbances, nausea, vomiting, confusion, dyspnea

Patient/Family Education

Instruct patient to take medication twice daily, with first dose in morning and second dose 7 hr later.
Extended release tablets should be taken in the morning on rising.
Do not crush or chew tablets.
Caution patient not to stop taking medication suddenly; withdrawal syndrome may occur.
Advise patient to notify physician if effectiveness of therapy decreases over time; tolerance may develop.
Instruct patient to report the following symptoms to physician: Nausea, vomiting, abdominal pain, appetite loss, persistent headache, faintness, apprehension, restlessness, chest pain, flushing, excessive sweating, cold sweat, visual disturbances, fever, involuntary passing of urine and feces.
Caution patient to avoid sudden position changes to prevent orthostatic hypotension.
Instruct patient to avoid intake of alcoholic beverages or alcohol-containing products.