Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Fat redistribution: Over time, this medication may change how fat is distributed in your body and may change your body shape. You may notice increased fat in the upper back and neck, breast, around the back, chest, and stomach area; or loss of fat from the legs, arms, and face. The long-term effects of this are not known.
Immune reconstitution syndrome: This medication may cause immune reconstitution syndrome, where signs and symptoms of inflammation from previous infections appear. These symptoms occur soon after starting anti-HIV medication and can vary. They are thought to occur as a result of the immune system improving and being able to fight infections that have been present without symptoms (such as pneumonia, herpes, or tuberculosis). Report any new symptoms to your doctor as soon as possible.
Kidney function: If you have reduced kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. People with severely reduced kidney function should not take this medication.
Lactic acidosis and enlarged fatty liver: Zidovudine can cause a rare but serious condition called lactic acidosis (build-up of lactic acid in the blood) together with an enlarged liver. This tends to occur more often in women, especially if they are overweight. If you experience any of the following symptoms, call your doctor immediately:
- abdominal pain, swelling, or bloating
- feeling unwell
- shortness of breath
- weight loss
Your doctor will monitor your liver function periodically by ordering laboratory tests.
Liver function: Zidovudine is broken down by the liver so it can be removed from the body through the kidneys. Liver disease or reduced liver function may cause a build-up of zidovudine in the body and cause side effects. If you have liver disease or decreased liver function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
If you experience symptoms of liver problems (e.g., abdominal pain, persistent vomiting, feeling unwell, fever, itching, yellowing of the skin and eyes, dark urine), contact your doctor immediately.
Pancreatitis (inflammation of the pancreas): Zidovudine may cause or worsen pancreatitis. If you have a history of or are at risk for developing pancreatitis, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
If you develop signs of pancreatitis (e.g., upper left abdominal pain, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen), contact your doctor.
Red blood cells: Pure red cell aplasia is a rare bone marrow disorder characterized by a reduction in red blood cells produced by the bone marrow. Symptoms include pallor, weakness, shortness of breath, heart palpitations, and decreased blood pressure. If you experience any of these symptoms contact your doctor immediately.
Zidovudine may also cause low levels of red blood cells without causing red cell aplasia. This usually happens after this medication has been taken for more than 4 to 6 weeks. Your doctor should order regular blood tests to monitor for changes in the numbers of blood cells during treatment. If you experience symptoms of reduced red blood cell count (anemia) such as shortness of breath, feeling unusually tired or pale skin, contact your doctor as soon as possible.
Reduced white blood cells: Zidovudine can cause low levels of white blood cells. This usually happens after this medication has been taken for more than 4 to 6 weeks. Your doctor should order regular blood tests to monitor for changes in the numbers of blood cells during treatment. If you experience symptoms of an infection (e.g., fever, sore throat) contact your doctor immediately.
If you have low levels white blood cells, your doctor may consider a different combination of medications to treat your condition.
Stopping the medication: If you stop taking this medication, your HIV infection could get worse. Take the medication exactly as prescribed by your doctor and do not stop taking the medication without checking with your doctor first.
Pregnancy: The use of zidovudine after the first 14 weeks of pregnancy does not appear to increase the risk of birth defects. Zidovudine is used by pregnant women with HIV infection to prevent transmission of the virus to the unborn child.
Breast-feeding: Zidovudine passes into breast milk. Women who have HIV infection are cautioned against breast-feeding because of the risk of passing HIV to a baby who does not have the infection.