Isosorbide: Relief of heart or Chest pain

  • Type of Drug: Antianginal agent.
  • Prescribed for: Relief of heart or chest pain associated with angina pectoris. It is also used to control or prevent the recurrence of chest or heart pain and to reduce heart work in congestive heart failure and other similar conditions.
  • Brand Name: Isosorbide Mononitrate, Isosorbide Dinitrate.

General Information of Isosorbide

Isosorbide belongs to the class of drugs known as nitrates, which are used to treat pain associated with heart problems. The exact nature of their action is not fully understood. However, they are believed to relax muscles of veins and arteries. Isosorbide Dinitrate sublingual tablets begin working in 2 to 5 minutes and last for 1 to 3 hours. The regular tablets begin working in 20 to 40 minutes and continue for 4 to 6 hours. Sustained-release Isosorbide Dinitrate may take up to 4 hours to begin working and lasts for 6 to 8 hours. Isosorbide Mononitrate begins working in 30 to 60 minutes and lasts for an undetermined period of time.

Cautions and Warnings

If you know that you are allergic or sensitive to this drug or other drugs for heart pain, such as Nitroglycerin, do not use Isosorbide. Anyone who has a head injury or has recently had a head injury should use this drug with caution. Other conditions where the use of Isosorbide should be carefully considered are severe anemia, glaucoma, severe liver disease, overactive thyroid, cardiomyopathy (disease of the heart muscle), low blood pressure, recent heart attack, severe kidney problems, and overactive gastrointestinal tract.

Possible Side Effects

  • Common: headache and flushing of the skin, which should disappear after your body gets used to the drug. You may experience dizziness and weakness in the process. There is a possibility of blurred vision and dry mouth; if this happens, stop taking the drug and call your physician.
  • Less common: nausea, vomiting, weakness, sweating, rash with itching, redness, possible peeling. If these signs appear, discontinue the medication and consult your physician.

Drug Interactions

  • If you take Isosorbide, do not self-medicate with over-the-counter cough and cold remedies, since many of them contain ingredients that may aggravate heart disease.
  • Interaction with large amounts of whiskey, wine, or beer can cause rapid lowering of blood pressure, resulting in weakness, dizziness, and fainting.
  • Nitrates raise the amount of Dihydroergotamine absorbed into the blood, either raising blood pressure or working against the effect of Isosorbide.
  • Aspirin and calcium channel blockers can lead to higher Isosorbide blood levels and increased drug side effects.

Food Interactions of Isosorbide

Take Isosorbide on an empty stomach with a glass of water unless you get a headache that cannot be controlled by the usual means. If this occurs, the drug can be taken with meals.

Usual Dose

Isosorbide Dinitrate
10 to 20 mg, 4 times per day. The drug may be given in doses from 5 to 40 mg, 4 times per day.
Sustained-release: 40 to 80 mg every 8 to 12 hours.

Isosorbide Mononitrate
20 mg twice a day, with the 2 doses taken 7 hours apart. Usually, the first dose is taken on arising and the second dose is taken 7 hours later.

Isosorbide Overdosage

Isosorbide overdose can result in low blood pressure; very rapid heartbeat; flushing; perspiration (later on, your skin can become cold, bluish, and clammy); headache; heart palpitations; blurring and other visual disturbances; dizziness; nausea; vomiting; difficult, slow breathing; slow pulse; confusion; moderate fever; and paralysis. Overdose victims should be taken to a hospital emergency room at once for treatment. ALWAYS bring the medicine bottle with you.

Special Information

If you take this drug sublingually (under the tongue), be sure the tablet is fully dissolved before you swallow the drug. Do not crush or chew sustained-release capsules or tablets. Avoid alcoholic beverages while taking any of these drugs. Do not switch brands of Isosorbide without discussing this with your doctor or pharmacist. All brands of Isosorbide may not be equivalent.

Call your doctor if you develop a persistent headache, dizziness, facial flushing, blurred vision, or dry mouth.
If you take regular Isosorbide and forget to take a dose, take it as soon as you remember, unless it is within 2 hours of your next scheduled dose. If that happens, skip the dose you forgot and continue with your regular schedule.

If you take long-acting Isosorbide and miss a dose, take it as soon as you remember, unless it is within 6 hours of your next dose. In that case, skip the dose you forgot and continue with your regular schedule. Do not take a double dose.

Isosorbide Special Populations

This drug crosses into the blood circulation of a developing baby. It has not been found to cause birth defects. Nevertheless, pregnant women and those who might become pregnant should not take Isosorbide without their doctor’s approval. When the drug is considered essential by your doctor, its potential benefits must be carefully weighed against its risks.
This drug passes into breast milk but has caused no problems among breast-fed infants.

Older adults may take this medicine without special restriction. Be sure to follow your doctor’s directions, and report any side effects.