Definition Drug-induced immune haemolytic anaemia is a condition where the immune system destroys the red blood cells. This takes place in response to medication. The resulting low red blood cell count is known as anaemia.
What is going on in the body? Red blood cells transport oxygen to tissues of the body. In some people, medications can cause the immune system to attack and destroy red blood cells. This is known as haemolysis.
What are the signs and symptoms of the disease? Signs of haemolysis and the resulting shortage of red blood cells include:
What are the causes and risks of the disease? Haemolytic anaemia brought on by an immune reaction to a drug can be caused by a number of medications. Examples include many types of antibiotics and certain blood pressure drugs, among others.
What can be done to prevent the disease? People who have suffered from haemolytic anaemia due to a particular drug should avoid that medication. However, if the reaction has not occurred in the past it is hard to predict. Often, it cannot be avoided.
How is the disease diagnosed? The doctor will take the person's medical history and perform a physical examination. A FBC, or full blood count, is done to show low red blood cell count and the destruction of blood cells. Other blood tests can also be done to rule out other reasons for low red blood cell counts.
What are the long-term effects of the disease? Persons with haemolysis may develop severe shortage of red blood cells. People with underlying lung or heart disease may be at risk for further damage to the body if the blood counts remain low. For example, a person can suffer a heart attack as the result of very low blood counts
What are the risks to others? Drug induced immune haemolysis is not contagious. It does not place other people at risk.
What are the treatments for the disease? The primary treatment for the condition is to discontinue taking the medication that has caused the reaction. Blood counts, or FBC's, are monitored closely after this is done. Usually they will return to normal without further treatment. In rare cases, the person will need a blood transfusion. However, there is a significant risk that the immune system will destroy these red blood cells as well. Occasionally, a person will need immune-suppressing medications such as corticosteriods to stop the ongoing destruction of blood cells.
What are the side effects of the treatments? Since the medication that caused the haemolysis has to be discontinued, there is a danger that the condition this medication was used to treat will worsen. If medications are used to suppress the immune system, infection and other side effects may occur. These depend on the medication used.
What happens after treatment for the disease? The person is monitored to make sure his or her FBC returns to normal.
How is the disease monitored? The condition is monitored with repeated FBC blood tests to measure the number of red blood cells in the blood. Most people will make a full recovery once the medication is stopped and the immune process returns to normal.
Author: Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
