Generic name: Isosorbide dinitrate

Other brand names: Dilatrate-SR, Iso-Bid, Isordil Sublingual, Isordil Tembids, Isordil Tltradose, Sorbitrate, Sorbitrate SA.

Isordil is an anti-anginal agent. It works by relaxing muscles of the veins and arteries. 

Quick Facts About Isordil


Used to treat or prevent angina pectoris (crushing chest pain).

Isordil Dosage

Take capsules and tablets on an empty stomach. May crush tablets, not sustained release products. When stopping medication, gradually taper off according to doctor’s instructions. If taking sublingual tablet — when it is dissolving, do not eat, drink, smoke, or use tobacco.

  • Usual adult dose: sublingual (treatment of angina pectoris) — 2.5 to 5 milligrams. Sublingual (prevention of angina pectoris attack) — 5 or 10 milligrams taken every 2 to 3 hours. For prevention of chronic stable angina pectoris (immediately released Isordil) — 5 to 20 milligrams, up to 10 to 40 milligrams taken every 6 hours. For prevention of chronic stable angina pectoris (controlled-release Isordil) — 40 milligrams, up to 80 milligrams taken every 8 to 12 hours.
  • Usual child dose: not generally prescribed for children.
  • Missed dose: take as soon as possible, unless within 2 hours of next dose, or 6 hours of next dose for controlled-release tablets and capsules. In that case, do not take missed dose; go back to regular schedule. Do not double doses.

Isordil Side Effects

Overdose symptoms:

bloody diarrhea, coma, confusion, convulsions, fainting, fever, flushed and perspiring skin followed by cold and blue skin, nausea, palpitations, paralysis, rapid decrease in blood pressure, rapid then difficult and slow breathing, slow pulse, throbbing headache, vertigo, visual disturbances, vomiting. If you suspect an overdose, immediately seek medical attention.

Severe overdose can be fatal.

More common side effects: headache. Other common side effects: dizziness, low blood pressure, weakness.

Less common or rare Isordil side effects: collapse, fainting, flushed skin, nausea, pallor, perspiration, rash, restlessness, skin inflammation and flaking, vomiting.


Inform your doctor before combining Isordil with:

other high blood pressure medications such as Cardizem and Procardia.

Alcohol use may immediately decrease blood pressure, thereby causing dizziness and fainting. 

Special Cautions

If pregnant or planning to become pregnant, inform your doctor immediately. Not known if Isordil appears in breast milk.

No special precautions apply to seniors.

Not generally prescribed for children.

  • Can cause severe low blood pressure, especially if standing up or sitting quickly. Use with caution if you are taking diuretics, or if you have: anemia, glaucoma, heart disease, low blood pressure, previous head injury or heart attack, or thyroid disease.
  • If allergic to this medication or other nitrates or nitrites, should not take.
  • Inform your doctor if you notice this medication is losing its effectiveness.

Note: provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Isordil side effects, please contact your healthcare provider.