isosorbide dinitrate(redirected from isochron)
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Pharmacologic class: Nitrate
Therapeutic class: Antianginal
Pregnancy risk category C
Promotes peripheral vasodilation and reduces preload and afterload, decreasing myocardial oxygen consumption and increasing cardiac output. Also dilates coronary arteries, increasing blood flow and improving collateral circulation.
Capsules: 40 mg
Capsules (extended-release): 40 mg
Tablets: 2.5 mg, 5 mg, 10 mg, 20 mg, 30 mg, 40 mg
Tablets (chewable): 5 mg, 10 mg
Tablets (extended-release): 20 mg, 40 mg
Tablets (sublingual): 2.5 mg, 5 mg, 10 mg
Tablets: 10 mg, 20 mg
Tablets (extended-release): 30 mg, 60 mg, 120 mg
Indications and dosages
➣ Treatment and prophylaxis in situations likely to provoke acute angina pectoris
Adults: 2.5 to 5 mg S.L. May repeat dose q 5 to 10 minutes for a total of three doses in 15 to 30 minutes.
➣ Prophylaxis of angina pectoris
Adults: 5 to 40 mg P.O. (dinitrate conventional tablets) two to three times daily. Or 5 to 20 mg (mononitrate conventional tablets) b.i.d. Or 30 to 60 mg (mononitrate extended-release tablets) once daily. After several days, dosage may be increased to 120 mg (given as single 120-mg tablet or two 60-mg tablets) once daily. Rarely, 240 mg/day (mononitrate extended-release tablets) may be needed.
• Heart failure
• Hypersensitivity to drug
• Severe anemia
• Acute myocardial infarction
• Angle-closure glaucoma
• Concurrent sildenafil therapy
Use cautiously in:
• head trauma, volume depletion
• elderly patients
• pregnant or breastfeeding patients
• Give oral form 30 minutes before or 1 to 2 hours after a meal. Make sure patient swallows tablets or capsules whole.
• Have patient wet S.L. tablet with saliva before placing it under tongue. To avoid tingling sensation, have him place tablet in buccal pouch.
CNS: dizziness, headache, apprehension, asthenia, syncope
CV: orthostatic hypotension, tachycardia, paradoxical bradycardia, rebound hypertension
EENT: sublingual burning (with S.L. route)
GI: nausea, vomiting, dry mouth, abdominal pain
Drug-drug. Aspirin: increased isosorbide blood level and effects
Beta-adrenergic blockers, calcium channel blockers, phenothiazines: additive hypotension
Dihydroergotamine: antagonism of dihydroergotamine effects
Sildenafil: severe and potentially fatal hypotension
Drug-diagnostic tests. Cholesterol: decreased level
Methemoglobin, urine vanillylmandelic acid: increased levels
• Monitor ECG and vital signs closely, especially blood pressure.
☞ In suspected overdose, assess for signs and symptoms of increased intracranial pressure.
• Monitor arterial blood gas values and methemoglobin levels.
• Teach patient to take oral drug 30 minutes before or 1 to 2 hours after a meal.
• Inform patient that drug may cause headache. Advise him to treat headache as usual and not to alter drug schedule. If headache persists, tell him to contact prescriber.
• Instruct patient to move slowly when sitting up or standing, to avoid dizziness or light-headedness from sudden blood pressure decrease.
• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs and tests mentioned above.