IMPORTANT WARNING:
Lamivudine and zidovudine may decrease the number of certain cells in your blood, including red and white blood cells. Tell your doctor if you have or have ever had a low number of any type of blood cells or any blood disorders such as anemia (a lower than normal number of red blood cells) or bone marrow problems. If you experience any of the following symptoms, call your doctor immediately: unusual bleeding or bruising; shortness of breath; pale skin; fever, sore throat, chills, and other signs of infection; or unusual tiredness or weakness.
Lamivudine and zidovudine may cause muscle disorders, especially when used for a long period of time. Tell your doctor if you have or have ever had any disease of the muscles or muscle weakness. If you experience muscle pain or muscle weakness, call your doctor immediately.
Lamivudine and zidovudine may cause life-threatening damage to the liver and a potentially life-threatening condition called lactic acidosis (buildup of lactic acid in the blood). Tell your doctor if you have or have ever had liver disease. If you have liver disease your doctor will probably tell you not to take lamivudine and zidovudine. If you experience any of the following symptoms, call your doctor immediately or get emergency medical treatment: nausea, vomiting, pain in the upper right part of your stomach, loss of appetite, extreme tiredness, unusual bleeding or bruising, weakness, dizziness, lightheadedness, fast or irregular heartbeat, trouble breathing, dark yellow or brown urine, light-colored bowel movements, yellowing of the skin or eyes, feeling cold, especially in the arms or legs, or muscle pain that is different than any muscle pain you usually experience.
Tell your doctor if you have or think you may have hepatitis B virus infection (HBV; an ongoing liver infection). Your doctor may test you to see if you have HBV before you begin your treatment with lamivudine and zidovudine. If you have HBV and you take lamivudine and zidovudine, your condition may suddenly worsen when you stop taking lamivudine and zidovudine. Your doctor will examine you and order lab tests regularly for several months after you stop taking lamivudine to see if your HBV has worsened.
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests during and after your treatment to check your body's response to lamivudine and zidovudine.