Most Common Effect

• The most common side effect associated with Imdur, as noted by Physicians' Desktop Reference, is mild to moderate headaches. This effect usually disappears after using the drug for a short time.
  
  

Blood Pressure Effect

• Imdur can cause very low blood pressure, with symptoms of dizziness, lightheadedness and fainting. These symptoms are more common when a person gets up from sitting or lying down. Drinking alcohol while taking Imdur also can cause a drop in blood pressure.
  
  

Withdrawal

• People should not suddenly discontinue Imdur use, because severe angina side effects can occur.
  
  

Allergic Reaction

• Rarely, some people have an allergic reaction to Imdur. Symptoms include rash, facial swelling, severe dizziness and trouble breathing.
  
  

Drug Interactions

• Several drugs can interact with Imdur and cause severe reactions. Drugs that should be avoided include those that treat erectile dysfunction, medications that lower high blood pressure, diuretics and certain migraine medications.