Why is this medication prescribed?
Isosorbide immediate-release tablets are used for the management of angina (chest pain) in people who have coronary artery disease (narrowing of the blood vessels that supply blood to the heart). Isosorbide extended-release (long-acting) tablets and extended-release capsules are used for the management of chest pain in people who have coronary artery disease. Isosorbide can only be used to prevent angina; it cannot be used to treat an episode of angina once it has begun. Isosorbide is in a class of medications called vasodilators. It works by relaxing the blood vessels so the heart does not need to work as hard and therefore does not need as much oxygen.
How should this medicine be used?
Isosorbide comes as a tablet, an extended-release (long-acting) tablet, and an extended-release capsule to take by mouth. The tablet usually is taken two or three times daily. The extended-release tablet usually is taken once daily in the morning. The extended-release capsule usually is taken once daily.
Do not crush, chew, or divide the extended-release tablets or capsules. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take isosorbide exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Isosorbide controls chest pain but does not cure coronary artery disease. Continue to take isosorbide even if you feel well. Do not stop taking isosorbide without talking to your doctor.
Isosorbide may not work as well after you have taken it for some time or if you have taken many doses. Your doctor will schedule your doses so that there is a period of time every day when you are not exposed to isosorbide. If your chest pain attacks happen more often, last longer, or become more severe at any time during your treatment, call your doctor.
Other uses for this medicine
Isosorbide tablets are also used with other medications to treat heart failure. Talk to your doctor about the possible risks of using this medication for your condition.
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
What special precautions should I follow?
Before taking isosorbide,
- tell your doctor and pharmacist if you are allergic to isosorbide; nitroglycerin tablets, patches, or ointment; any other medications, or any of the ingredients in isosorbide tablets, extended-release tablets, or extended-release capsules. Ask your pharmacist for a list of the ingredients.
- tell your doctor if you are taking or have recently taken riociguat (Adempas) or a phosphodiesterase inhibitor (PDE-5) such as avanafil (Stendra), sildenafil (Revatio, Viagra), tadalafil (Adcirca, Cialis), and vardenafil (Levitra, Staxyn). Your doctor will probably tell you not to take isosorbide if you are taking one of these medications.
- tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: aspirin; beta blockers such as atenolol (Tenormin, Tenoretic), carteolol , labetalol (Trandate), metoprolol (Lopressor, Toprol-XL, in Dutoprol, in Lopressor HCT), nadolol (Corgard, in Corzide), propranolol (Hemangeol, Inderal, Innopran), sotalol (Betapace, Sorine, Sotylize), and timolol; calcium channel blockers such as amlodipine (Norvasc, in Amturnide, in Tekamlo), diltiazem (Cardizem, Cartia, Dilt-CD, others), felodipine (Plendil), isradipine, nifedipine (Adalat CC, Afeditab, Procardia), and verapamil (Calan, Covera, Verelan); ergot-type medications such as bromocriptine (Cycloset, Parlodel), cabergoline, dihydroergotamine (D.H.E. 45, Migranal), ergoloid mesylates (Hydergine), ergotamine (in Cafergot, in Migergot), methylergonovine (Methergine), methysergide (Sansert; no longer available in the U.S.), and pergolide (Permax; no longer available in the U.S.); medications for high blood pressure, heart failure, or an irregular heartbeat. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- tell your doctor if you may be dehydrated, if you have recently had a heart attack, or if you have or have ever had heart failure, low blood pressure, or hypertrophic cardiomyopathy (thickening of the heart muscles).
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking isosorbide, call your doctor.
- if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking isosorbide.
- ask your doctor about the safe use of alcoholic beverages while you are taking isosorbide. Alcohol can make the side effects from isosorbide worse.
- you should know that isosorbide may cause dizziness, lightheadedness, and fainting when you get up too quickly from a lying position, or at any time, especially if you have been drinking alcoholic beverages. To avoid this problem, get up slowly, resting your feet on the floor for a few minutes before standing up. Take extra precautions to avoid falling during your treatment with isosorbide.
- you should know that you may experience headaches every day during your treatment with isosorbide. These headaches may be a sign that the medication is working as it should. Do not try to change the times or the way that you take isosorbide in order to avoid headaches because then the medication may not work as well. Your doctor may tell you to take a pain reliever to treat your headaches.
What special dietary instructions should I follow?
Unless your doctor tells you otherwise, continue your normal diet.
What should I do if I forget a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
What side effects can this medication cause?
Isosorbide may cause side effects. Tell your doctor if any of these symptoms or those listed in the SPECIAL PRECAUTIONS section are severe or do not go away:
Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:
- worsening chest pain
- difficulty breathing or swallowing
Isosorbide may cause other side effects. Call your doctor if you have any unusual problems while you are using this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].
What should I know about storage and disposal of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
Symptoms of overdose may include:
- slow or pounding heartbeat
- bloody diarrhea
- shortness of breath
- cold, clammy skin
- loss of ability to move the body
- coma (loss of consciousness for a period of time)
What other information should I know?
Keep all appointments with your doctor.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Brand names of combination products
- BiDil® (containing Hydralazine and Isosorbide Dinitrate)
¶ This branded product is no longer on the market. Generic alternatives may be available.