You should not use this medicine if you have had an allergic reaction to isosorbide or similar medicines (such as nitroglycerin or Isordil®). You should not use this medicine if you are also using Viagra®.
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
Make sure your doctor knows if you are also using diuretics or "water pills" (such as furosemide, hydrochlorothiazide, Hyzaar®), or heart or blood pressure medicine (such as verapamil, Adalat®, Calan®, Cardizem®, Lotrel®, Plendil®, Procardia®, Tiazac®).
Do not drink alcohol while you are using this medicine.
Make sure your doctor knows if you are pregnant or breastfeeding, or if you have low blood pressure, congestive heart failure (CHF), an enlarged heart, or other heart problems.
Medicines that treat chest pain sometimes cause headaches. These headaches are a sign that the medicine is working. Do not stop taking the medicine or change the time you take it in order to avoid the headaches. You may take aspirin or Tylenol® to relieve the headache. If you have severe pain, talk with your doctor.
This medicine may make you dizzy. Avoid driving, using machines, or doing anything else that could be dangerous if you are not alert. You may feel lightheaded when standing, so stand up slowly.
Do not stop using this medicine suddenly without asking your doctor. You may need to slowly decrease your dose before stopping it completely.