Isosorbide Dinitrate (Isordil, Dilitrate-SR, Sorbitrate, Timecelles)

Category:

• Cardiac

Description:

• Antianginal agent

Indications:

• Prevention of angina pectoris

• Relief of acute anginal episodes and prophylaxis prior to events likely to provoke an attack

• CHF (non-FDA approved)

• Hypertension (acute) (non-FDA approved)

Contraindications:

• Hypersensitivity to nitrates, severe anemia, close-angle glaucoma, postural hypotension

• Head trauma

Precautions:

• Pregnancy category C; use caution in nursing mothers

• Acute MI, hypertrophic cardiomyopathy, glaucoma

• Volume depletion, hypotension, abrupt withdrawal

• Continuous delivery without nitrate-free interval (tolerance develops)

Adverse Reactions (Side Effects):

• CNS: agitation, anxiety, apprehension, confusion, dizziness, dyscoordination, headache, hypoesthesia, hypokinesia, insomnia, nervousness, nightmares, restlessness, vertigo, weakness

• CV: atrial fibrillation, cardiovascular collapse, crescendo angina, dysrhythmias, edema, hypotension, PVC’s, rebound hypertension, retrosternal discomfort, syncope, tachycardia

• EENT: blurred vision, diplopia

• GI: abdominal pain, diarrhea, dyspepsia, involuntary passing of feces, nausea, tenesmus, vomiting

• GU: dysuria, impotence, involuntary passing of urine, urinary frequency

• HEME: hemolytic anemia, methemoglobinemia

• MS: arthralgia, muscle twitching

• SKIN: cold sweat, crusty skin lesions, exfoliative dermatitis, flushing, pallor, perspiration, pruritis, rash

Dosage:

Administered orally: Asymmetric dosing regimens provide a daily nitrate-free interval to minimize the development of tolerance.

• Adult:   

  • SL 2.5-5mg initially, titrate upward until angina is relieved or side effects limit the dose; 

  • chewable tablets 5mg initially, titrate upward until angina is relieved or side effects limit the dose; 

  • PO 5-20mg 2-3 times daily initially (last dose no later than 1900), maintenance 10-40mg 2-3 times daily (last dose no later than 1900); 

  • PO SUS REL 40mg 1-2 times daily initially (last dose no later than 1400), maintenance 40-80mg 1-2 times daily (last dose no later than 1400)

Special considerations:

• Headache may be a marker for drug activity; do not try to avoid by altering treatment schedule; aspirin or acetaminophen may be used for relief

• Dissolve SL tablets under tongue; do not crush, chew, or swallow

• Do not crush chewable tablets before administering

• Avoid alcohol

• Make changes in position slowly to prevent fainting